Commercial Technology Research Articles

Enhancing Photostability of Complex Lead Halides through Modification with Antibacterial Drug Octenidine.

The high power-conversion efficiencies of hybrid perovskite solar cells encourage many researchers. However, their limited photostability represents a serious obstacle to the commercialization of this promising technology. Herein, we present an efficient method for improving the intrinsic photostability of a series of commonly used perovskite material formulations such as MAPbI3, FAPbI3, Cs0.12FA0.88PbI3, and Cs0.10MA0.15FA0.75PbI3 through modification with octenidine dihydroiodide (OctI2), which is a widely used antibacterial drug with two substituted pyridyl groups and two cationic centers in its molecular framework. The most impressive stabilizing effects were observed in the case of FAPbI3 and Cs0.12FA0.88PbI3 absorbers that were manifested in significant suppression or even blocking of the undesirable perovskite films' recrystallization and other decomposition pathways upon continuous 110 mW/cm2 light exposure. The achieved material photostability-within 9000 h for the Oct(FA)n-1PbnI3n+1 (n = 40-400) and 20,000 h for Oct(Cs0.12FA0.88)n-1PbnI3n+1 (where n = 40-400) formulations-matches the highest values ever reported for complex lead halides. It is important to note that the stabilizing effect is maintained when OctI2 is used only as a perovskite surface-modifying agent. Using a two-cation perovskite composition as an example, we showed that the performances of the solar cells based on the developed Oct(Cs0.12FA0.88)399Pb400I1201 absorber material are comparable to that of the reference devices based on the unmodified perovskite composition. These findings indicate a great potential of the proposed approach in the design of new highly photostable and efficient light absorbers. We believe that the results of this study will also help to establish important guidelines for the rational material design to improve the operational stability of perovskite solar cells.

Characterization of the performance of Ti doped α-C/α-C multilayer coating on SS316L as bipolar plates for PEMFC

In order to improve the corrosion resistance and conductivity of 316L stainless steel (SS316L) in the PEMFC (proton exchange membrane fuel cells) environment, DC-balanced magnetron sputtering was used to deposit Ti doped α-C/α-C multilayer coating on SS316L. The influence of coating structure on its micromorphology and phase composition is characterized, and the coating corrosion and conductivity were further explored. Notably, the investigation reveals that multi-layer structure can inhibit the growth of columnar crystal structure and refine the coating surface, which gradually decreased the coating porosity of from 4.54 % (1 layer) to 0.21 % (4 layers), and the passivation current density decreases to 0.22 μA/cm2 at 0.6 V, remarkably better than the targets. In addition, the introduction of Ti-doped α-C layer further promoted the sp2 hybridization of the coating, its interfacial contact resistance (ICR) value gradually decreased from 5.28 mΩ·cm2 (1 layer) to 2.28 mΩ·cm2 (4 layers) under 1.4 MPa. Therefore, the multilayer composite structure coating significantly enhances the conductivity and corrosion resistance of the SS316L bipolar plate, are more practically applied for commercialization of PEMFC technology.

Ultra-Low Loading IrO2 on Porous Transport Layer for Catalysis of Proton Exchange Membrane Water Electrolysis

Proton Exchange Membrane Water Electrolysis (PEMWE) is a commercial technology with specific advantages such as high-power density and rapid start-up times, which makes it a perfect match to produce hydrogen from intermittent renewable energy sources (green H2). [1] However, very scarce materials, such as iridium and platinum, are currently used as catalysts and protection coatings to withstand the harsh operating conditions in PEMWE. Iridium is the anode catalyst in the state-of-the-art PEMWE, with loadings in the range 1-2 mg/cm2. This metric translates into using 200-500 kg of iridium per GW, which accounts for roughly 10% of the global iridium production per year. Reducing iridium usage in PEMWE is critical to realize the 10-100 GW/year growth in green H2 power. [2,3]To significantly reduce the Ir loading, while maintaining the lateral conductivity, we coated the iridium catalyst by atmospheric spatial Atomic Layer Deposition (sALD) on titanium porous transport layer (PTL), which acts as the electrically conductive substrate. The coating renders ultra-low iridium loadings, which is 100-200 times less iridium than the state-of-the-art catalyst coated membrane technology, while retaining ca. 60-80% of the performance (in terms of current density), with durability demonstrated up to 100 h (see Figure 1). We will also show here that protection coatings on the titanium PTL are beneficial to yield good durability with these ultra-low loadings of iridium and demonstrated that sALD has the potential to produce non-PGM based protection coatings.[1] Barbir, F. Solar Energy 78 (2005) 661-669.[2] Gavrilova, A., Wieclawska, S.M. “Towards a green future. Part 2” (2021). TNO report 21-12158.[3] Minke, C., Suermann, M., Bensmann, B., & Hanke-Rauschenbach, R. J. Hydrogen Energy 46 (2021) 23581-23590. Figure 1

Titania nanoengineering towards efficient plasmonic photocatalysis: Mono- and bi-metal-modified mesoporous microballs built of faceted anatase

Preparation of porous micro-sized materials with solar response is urgent for fast commercialization of green technologies based on semiconductor photocatalysis. Here, mesoporous titania microballs composed of nanocrystalline anatase with exposed facets were prepared by a sub-zero sol-gel method followed by hydrothermal/alcohothermal crystallization. The mechanism of microballs formation and the influence of preparation conditions on the properties, and thus resultant photocatalytic activity, were investigated in detail. The photocatalytic performance was examined in four reaction systems under UV/vis irradiation, i.e., oxidative decomposition of methyl orange (MO) dye, hydrogen evolution, degradation of tetracycline (TC) antibiotic, and carbon dioxide reduction. Moreover, hydrogen generation was also examined under visible-light (vis) irradiation. Amorphous and faceted (octahedral- and decahedral-based) microballs were additionally modified with nanoparticles (NPs) of noble metals (Pt, Au, Ag, Pt/Au, Pt/Ag) for both UV-activity enhancement and vis response (i.e., plasmonic photocatalysis). It has been found that nano-architecture of microballs might be controlled by the ratio of alcohol to water used during hydrothermal/alcohothermal treatment. Accordingly, highly active microballs composed of pure octahedral- or decahedral-shaped anatase crystals, i.e., with {101} facets only (bipyramids) or eight {101} and two {001} facets, respectively, could be synthesized by a facile and environmental-friendly method. The versatility and high activity of faceted microballs have been confirmed in both oxidation and reduction reactions under UV and/or vis irradiation (comparable performance to that by famous P25). Decahedral-based samples exhibit usually higher photocatalytic activity than octahedral ones, despite worse photoelectronic properties (charge carriers’ separation, electron transport capacity and photocurrent density), due to higher hydrophilicity. However, single type {101} facet photocatalyst (octahedral shape) is preferable for efficient CO2 adsorption and reduction into CO and CH4. Among noble metals, though platinum shows much higher positive effect on UV activity, gold is responsible for the highest activity under vis, which corresponds to the strongest plasmonic filed enhancement, as proven by finite difference time domain (FDTD) simulations. Concluding, micro-sized balls composed of faceted anatase are undoubtedly prospective photocatalyst for diverse environmental applications.

Metal-Doped ZIF-8 Derived Hollow Carbon for High-Performance Lithium-Sulfur Batteries

Lithium-ion (Li-ion) batteries have been ubiquitously utilized in the modernized world in portable electronic, electrical vehicles, and grid-scale energy storage. However, demand satisfaction for traditional Li-ion batteries is becoming difficult due to their limited capacity and energy density. Moreover, there are challenges related to the availability of non-renewable critical materials for Li-ion batteries such as Co, Ni, and graphite, and environmental pollution during battery creation and recycling. Further neglect of these problems will lead to dramatic consequences at which batteries will become a part of the environmental problems but not a solution to these problems as they should be. Therefore, it is highly imperative to explore novel battery systems that show high energy density, low production cost and low environmental pollution during production, use and recycling. One of the most promising candidates is the lithium-sulphur (LiS) battery, which offers various advantages such as high energy density, high theoretical specific capacity, and affordable cost, because of the high availability of elemental sulphur and carbon used in this type of battery. The theoretical gravimetric energy density of LiS batteries is 2567 Wh/kg which is 4.5 times higher than the energy density of conventional Li-ion batteries. Despite the richness of sulphur in the Earth’s crust and its prominent merits in energy density and cost, several problems have restricted the development of LiS batteries for commercialization. The most notorious and intractable problem is the high solubility of the sulphur species (Li2Sx, 3≤x≤8) in common Li-ion battery electrolytes that leads to the so-called lithium polysulfide (LiPS) shuttle effect and loss of battery capacity, Li metal anode corrosion, and low coulombic efficiency during interaction of the LiPS with Li metal anode. The most prospective solution to address the above drawbacks is sulphur incorporation with a porous, high-conductive carbon host that will tolerate sulphur volume expansion, improve the conductivity of the electrode, prevent the shuttle effect, and allow reversible lithium-ion migration during charging and discharging.However, to achieve the excellent operation performances of the porous carbon host its properties should be carefully tuned and the LiPS absorption ability of the carbon host should be improved for example by metal oxide doping. Many different strategies for the creation of the required material were proposed in recent years. Unfortunately, many proposed synthetic methods require a hard template to provide fine control of the pore distribution in the materials, which is a significant drawback as in this case harsh conditions are required for template removal. In addition, the formation of doped carbons with good electrical conductivity often demands high temperatures, simultaneously causing the undesirable reduction of metal cations to their metallic state followed by the aggregation to form nanoparticles, together with the collapse of the carbon matrices. Therefore, it still urgently needs to find a new strategy to produce a porous carbon host for the sulfur with fine porosity and good lithium polysulfide absorption ability, which purpose to accelerate the successful commercialization of this battery technology on the market.In our current work, we are investigating the possibility to synthesize finely dispersed metal oxide catalysts on hollow N-doped porous carbon capsules produced from zeolitic imidazolate framework (ZIF-8). The coating of the ZIF-8 with metal–tannic acid coordination polymer allows to uniformly dispersed metal oxide nanoparticles, such as Fe2O3, MnO, CoO etc., on hollow carbon capsules after the pyrolysis process. Moreover, the carbon produced by ZIF-8 pyrolysis is expected to be both doped with nitrogen and highly porous, which should have a positive effect on the maximum sulfur loading possibility in the carbon host and lithium polysulfide absorption ability. In addition, the used approach for the synthesis of the hollow N-doped porous carbon allows the distribution of multicomponent metal oxide nanoparticles on the surface of the hollow carbon capsules, which may have a synergetic effect and improve the lithium polysulfide absorption ability of the produced materials. The structural, compositional, and morphological properties of the created material are investigated using SEM, EDS, XPS, Raman spectroscopy, FTIR and TGA techniques. The effect of the different metal oxide nanoparticles and their combinations on the lithium polysulfide absorption ability of the synthesized materials are investigated by analysis of the electrochemical performances of the Li-S batteries, where synthesized material was used as the sulfur host during the creation of the Li-S battery cathode.

Investigating the Effects on Replacing Platinum by Molybdenum as Cathode Electrocatalysts in Proton Exchange Membrane Water Electrolysis

Water electrolysis coupled to renewable energy sources has become in a crucial technique for the green hydrogen production. Hydrogen economy is currently in the spotlight to solve energy demands due to its advantages such as clean, sustainable, low footprint, as well as high-power density which is 3 times above gasoline and diesel. To produce large quantities of hydrogen, proton exchange membrane water electrolysis (PEMWE) has arisen as a promising system to solve hydrogen demands. The heart of the PEMWE consists in a membrane electrode assembly (MEA), where two gas diffusion layers (GDLs), hosting the respective catalysts, are sandwiched between an ionomer membrane. Commonly, noble metals are needed as catalyst in the anode (Ir, Ru) and cathode (Pt) to reach high current densities maintaining low cell voltages. The large content of noble metals, their high cost, and accelerated corrosion rates at high cell voltages are some drawbacks that limit the industrialization and commercialization of PEMWE technology. Replacing, decreasing, or simply extending the operational lifetime of these noble metals have a positive impact on the hydrogen economy. Molybdenum is an earth-abundant metal with low-cost which has been already used to produce highly active electrocatalysts, that can potentially replace Pt. However, most electrocatalytic studies are restricted to three-electrode cells with different operational conditions than those employed in PEM cells. The latter makes a complicated task to predict the performance of the catalyst and stability under relevant instrial applications. Here, we investigated the viability of using three selected Mo-based nanomaterials (1T’-MoS2, Co-MoS2, and ß-Mo2C) as potential electrocatalysts to replace Pt in PEMWE systems. We investigated the effects of replacing Pt in the catalyst loading, charge transfer resistance, kinetics, operational stability, and hydrogen production efficiency during PEMWE operation. Furthermore, we developed a methodology to identify the effects of tuning the cathode catalyst while keeping the anode catalyst in the overall kinetics of PEMWE system. Our results point that electrochemical performance in traditional open cell might not strictly predict the performance that could be seen in PEMWE cells due to differences in interfaces, contact between the components and porosity of the macroscopic catalyst layers. Among the catalyst studied, 1T’-MoS2 exhibited low overpotential associated to low charge transfer resistance while reaching 1 A cm-2 at 1.9 V. Our study highlights the importance to continue developing efficient electrocatalysts to replace noble metals suitable for PEMWE systems. Figure 1

Te hexagonal nanotubes with fast 1-dimensional Zn ion diffusion for high-performance zinc-ion battery cathodes

The need for advanced next-generation secondary batteries have been urgently demanded for improved, sustainable, and eco-friendly energy storage systems. Aqueous rechargeable zinc ion batteries (ARZIBs) have garnered substantial attention as a substitute for lithium-ion batteries owing to their exceptional stability, environmentally friendly features, and cost-effectiveness. In this study, it is found that tellurium hexagonal nanotubes with a unique crystal growth orientation of [001] are of promising cathode materials for enhancing the performance of zinc ion batteries owing to their outstanding reaction kinetic properties. Additionally, the hollow interior of the nanotubes effectively mitigates the volume changes of tellurium during the charging and discharging processes. These research findings are expected to solidify the potential of tellurium hexagonal nanotubes as reliable cathode materials, significantly contributing to the commercialization of zinc ion battery technology in the future.

(Invited) Recent Advances and Challenges of MOCVD-Grown AlScN/GaN HEMTs

The allocated frequency bands of next-generation wireless communication networks will be shifting further up in the spectrum to be able to meet the stringent data rate requirements. Doing so, demands higher bandwidth capabilities from the electronic devices in the RF chain. Numerous cutting-edge systems are using AlGaN/GaN-HEMT based components, in particular in the transmit chain, due to their favorable combination of output power and bandwidth capability. Still, this semiconductor technology is approaching an upper bound in this regard, known as the Bode-Fano limit. Devices based on an AlScN/GaN heterointerface have been identified as candidates to push these boundaries and enable components that deliver higher power over a broader frequency range. We report on the status of MOCVD-grown AlScN/GaN HEMTs, their current capabilities but also on challenges that still hamper the exploitation of the material system's full potential.The first reported AlScN/GaN HEMTs were fabricated on epitaxial stacks grown by MBE. However, the majority of commercial GaN-based HEMT technologies is relying on MOCVD-grown epitaxy due to higher growth rate and lower cost of operation. We managed to grow AlScN/GaN heterostructures showing sheet carrier densities (nS) of up to 3·1013cm-2 and mobilities of 1100 cm2/Vs. These results were achieved with a MOCVD reactor that had been modified to cope with the low vapor pressure of the used precursors Cp3Sc and (MCp)2ScCl. Depending on the temperature, the obtained growth rates were as high as 0.015 nm/s. Currently, further precursors with allegedly higher vapor pressure are evaluated that should allow for even higher growth rates, further improving the quality of the fabricated heterostructures. Furthermore, HEMT devices were fabricated on top of the epitaxial wafers that showed power densities (Pout) of up to 8.4 W/mm and power-added efficiencies (PAE) of more than 48 % at a frequency of 30 GHz, even surpassing the current state-of-the-art in terms of combined Pout and PAE of Ga-polar devices.However, there are still a number of unsolved issues visible in most reported AlScN/GaN HEMT devices, regardless of the used growth method. One is concerning the level of leakage currents and the consequential premature soft breakdown. The root cause of this phenomena is not yet fully understood but is believed to originate from poor dielectric/isolating properties of the Sc-containing barrier. This hypothesis is supported by a comparably high level of impurites that is found in the AlScN layers. Minimizing theses residuals by purification of the precursors is, therefore, necessary to further improve the electrical device characteristics. Secondly, transport properties of AlScN/GaN heterointerfaces are not as well studied as more established junctions, e.g., AlGaN/GaN and AlN/GaN. An important parameter that has not been experimentally identified for 2DEGs induced by AlScN/GaN heterojunctions yet, is the saturation drift velocity (vsat). It is of particular importance since the Bode-Fano limit, among other, depends on it. Since the extension of the latter is one of the great promises of AlScN/GaN devices, it is clear that the value of vsat is essential to know in order to make quantitative predictions of the level of improvement that is achievable in terms of bandwidth capability but also with regard to power density.We will give an overview of recent advances of MOCVD-grown AlScN/GaN HEMTs with respect to their capability to extend on the achievable performance level of present GaN-based devices, in particular in the millimeter-wave frequency range. Further, we will benchmark the results against other competing technologies, i.e. GaAs pHEMT and Si-CMOS, to give an outlook of where optimized AlScN/GaN devices can takes us and where they cannot.

Analysis of PEM Membrane Electrode Assemblies Impact on the Levelized Cost of Hydrogen

Plug is building an end-to-end green hydrogen ecosystem to help its customers meet their business goals and decarbonize the economy. This hydrogen ecosystem is inclusive of production, storage, delivery, and energy generation. As the largest user of liquid hydrogen globally, Plug Power plans to build and operate green hydrogen production plants across North America and Europe. Plug’s hydrogen production plants are based on electrolyzer systems featuring internally developed proton exchange membrane (PEM) based water electrolysis membrane electrode assemblies (MEAs). This paper will review the state of commercial PEM water electrolysis MEAs and provide insight as to what advances in MEA technology are needed to produce hydrogen at a levelized cost of $1/kg.The cell polarization curves for two modeled PEM MEAs are shown in Figure 1. They represent the performance of both commercial and future PEM water electrolyzer technology. As the applied current density to the cell increases, so does the cell voltage, and thus the energy required to produce a kilogram of hydrogen. As the MEA technology in the stack matures, the applied current density, and thus, the hydrogen production rate can increase at a set efficiency. A 155 cell, 1,000 cm2 active area, electrolyzer stack featuring commercial MEAs would produce approximately 220 kg-H2/day at an efficiency of 49 kWh/kg-H2. With the future MEAs, this same stack, operating at the same efficiency, could produce as much as 1,200 kg-H2/day.A hydrogen plant with a production capability of 45 metric tons per day, featuring commercial MEAs, would produce hydrogen at a cost of approximately $6/kg when powered by energy at a price of $35/MWh. The MEA cost represents only a few percent of the total capital expenditure required to build a 45 metric ton hydrogen plant. Thus, MEAs would only contribute a few cents to the estimated $6/kg levelized cost of hydrogen (LCOH). They, however, are responsible for most of the energy consumed at a hydrogen plant. Therefore, the MEAs could account for 50%, or more, of the total cost to produce hydrogen. A savings of $328M to $410M can be realized or every $1/kg reduction in LCOH over the lifetime of a hydrogen plant. Thus, performance improvements in the MEA are paramount to making hydrogen production competitive with other energy carriers.The oxygen evolution catalyst featured in a future MEA would be required to achieve a greater than four-fold increase in activity. The PEM of the future MEA would also be required to support a substantial increase in proton transfer while maintaining its integrity for greater than 100,000 hours. These advances, as well as savings in hydrogen plant capital expenditures, are required to achieve a LCOH of approximately $1/kg at a fixed energy cost of $35/MWh. Even at the lowest projections for capital expenditures, most of the cost of hydrogen will be dominated by power consumption, further highlighting the importance of maturing PEM water electrolysis MEA technology. Figure 1

Volta: A Tool for Battery Screening Bridging the Gap between Virtual Electrode Materials and Practical Applications

For millennia, materials science has relied on the paradigm of empiricism to describe the physical world and to fuel technological advance. It was only some centuries ago that the paradigm of mathematical modelling was introduced, boosting scientific knowledge with the introduction of laws in the form of equations. Their predictive capability proved essential to the human understanding of nature, but, as the complexity of the problems increased over time, equations became more and more impenetrable, with analytical solutions being often rather challenging to determine. Electronic computers cut this Gordian knot for us, allowing for quick(er) calculations of approximate solutions to the equations mentioned above. [1]Battery science has greatly benefit from these advances: Density Functional Theory allowed for e.g. reliable quantifications of active materials’ figures of merit like stability or operational potential. The introduction of multiscale modelling was also allowed by this third paradigm of science, leveraging quick computation speeds to infer cell level properties from lower-level ones. [2]The data generated both with experimentation and computation has now accumulated, and a great amount is being published on platforms like, but not limited to, the Materials Project. [3] This is where science enters the so-called fourth paradigm, i.e. data driven science, [4] where statistical methods can contaminate and enhance the “traditional” physico-chemical ones.In fact, new approaches to materials screening are being published with increasing frequency, like neural networks able to predict material properties [5], or generative algorithms able to suggest novel materials. [6] It is important to notice that these methods rely heavily on data quality, hence are not to be seen as a substitute for first principle calculations, but rather as techniques able to expand their scope and capabilities.Battery science itself can greatly benefit from the fourth paradigm of science as well: it is in this context that we developed the present work, in an endeavor to tackle a specific issue in battery science: active materials screening has rarely considered the properties that emerge when coupling two active materials, embedding them into composite electrodes and connecting them electrically.The present work introduces a Python-based combinatorial materials screening workflow, named VOLTA. Its pipeline allows for a novel battery active material explorative workflow, that prioritizes the cell level performance indicators, like cell capacity and voltage profile. This is achieved by the construction of a starting dataset of both observed and virtual active materials from the Materials Project, the implementation of a physics-based pipeline for the assessment of practical electrode properties like porosity and thickness, [7] and the coupling of the electrodes into virtual cells, whose figures of merit are calculated, like voltage and capacity. The screening can be conducted by applying filters to these cell-level properties, achieving an indirect selection of the most suitable active materials.The approach is validated through comparison to current commercial battery technology, and we demonstrate that VOLTA is able to identify promising electrode materials for high energy batteries, like the well-known LCO, LNO and graphite. We also illustrate a case-study, where the pipeline is used in a low-voltage "battery discovery" problem. Bibliography [1] Agrawal, A., & Choudhary, A. (2016). Perspective: Materials informatics and big data: Realization of the “fourth paradigm” of science in materials science. APL Materials, 4(5), 053208.[2] Jain, A., Ong, S. P., Hautier, G., Chen, W., Richards, W. D., Dacek, S., Cholia, S., Gunter, D., Skinner, D., Ceder, G., & Persson, K. A. (2013). Commentary: The Materials Project: A materials genome approach to accelerating materials innovation. APL Materials, 1(1), 011002.[3] Franco, A. A., Rucci, A., Brandell, D., Frayret, C., Gaberscek, M., Jankowski, P., & Johansson, P. (2019). Boosting Rechargeable Batteries R&D by Multiscale Modeling: Myth or Reality? Chemical Reviews, 119(7), 4569–4627.[4] Hey, T., Tansley, S., Tolle, K., & Gray, J. (2009). The Fourth Paradigm: Data-Intensive Scientific Discovery. The Fourth Paradigm: Data-Intensive Scientific Discovery, 39–44.[5] Wang, A. Y.-T., Kauwe, S. K., Murdock, R. J., & Sparks, D. (2021). Compositionally-Restricted Attention-Based Network for Materials Property Predictions. Npj Computational Materials, 33.[6] Dan, Y., Zhao, Y., Li, X., Li, S., Hu, M., & Hu, J. (2020). Generative adversarial networks (GAN) based efficient sampling of chemical composition space for inverse design of inorganic materials. Npj Computational Materials, 6(1), 84.[7] Lombardo, T., Caro, F., Ngandjong, A. C., Hoock, J. B., Duquesnoy, M., Delepine, J. C., Ponchelet, A., Doison, S., & Franco, A. A. (2022). The ARTISTIC Online Calculator: Exploring the Impact of Lithium-Ion Battery Electrode Manufacturing Parameters Interactively Through Your Browser. Batteries & Supercaps, 5(3), e202100324.

Influence and Optimization of Gas Diffusion Layer Porosity Distribution along the Flow Direction on the Performance of Proton Exchange Membrane Fuel Cells

Influence and Optimization of Gas Diffusion Layer Porosity Distribution along the Flow Direction on the Performance of Proton Exchange Membrane Fuel Cells

A Doping-Induced SrCo0.4Fe0.6O3/CoFe2O4 Nanocomposite for Efficient Oxygen Evolution in Alkaline Media.

Perovskite and spinel oxides are promising alternatives to noble metal-based electrocatalysts for oxygen evolution reaction (OER). Herein, a novel perovskite/spinel nanocomposite comprised of SrCo0.4Fe0.6O3 and CoFe2O4 (SCF/CF) is prepared through a simple one-step method that incorporates iron doping into a SrCoO3- δ matrix, circumventing complex fabrication processes typical of these materials. At a Fe dopant content of 60%, the CoFe2O4 spinel phase is directly precipitated from the parent SrCo0.4Fe0.6O3 perovskite phase and the number of active B-site metals (Co/Fe) in the parent SCF can be maximized. This nanocomposite exhibits a remarkable OER activity in alkaline media with a small overpotentional of 294mV at 10mAcm-2. According to surface states analysis, the parent SCF perovskite remains in its pristine form under alkaline OER conditions, serving as a stable substrate, while the second spinel CF is covered by 5/8 monolayer (ML) O*, exhibiting considerable affinity toward the oxygen species involved in the OER. Analysis based on advanced OER microkinetic volcano model indicates that a 5/8 ML O* covered-CF is the origin for the remarkable activity of this nanocomposite. The results reported here significantly advance knowledge in OER and can boost application, scale-up and commercialisation of electrocatalytic technologies toward clean energy devices.

Augmented reality and radiology: visual enhancement or monopolized mirage.

Augmented reality (AR) exists on a spectrum, a mixed reality hybrid of virtual projections onto real surroundings. Superimposing conventional medical imaging onto the living patient offers vast potential for radiology, potentially revolutionising practice. The digital technology and user-interfaces that allow us to appreciate this enhanced environment however are complex, expensive, and development mainly limited to major commercial technology (Tech) firms. Hence, it is the activity of these consumer-based businesses that will inevitably dictate the available technology and therefore clinical application of AR. The release of mixed reality head-mounted displays in 2024, must therefore prompt a review of the current status of AR research in radiology, the need for further study and a discussion of the complicated relationship between consumer technology, clinical utility, and the risks of monopolisation.

Solar PV technologies selection for the design of photovoltaic installations in Mexico based on the analysis of meteorological satellite data from the region

Mexico’s expansive territory spans diverse climatic conditions, which directly influences the selection of commercial photovoltaic technologies. This study utilizes solar irradiance, temperature, and cloud index data (derived from satellite sources) to generate a suitability map for commercial solar panel technologies through the Analytical Hierarchy Process-Geographical Information Systems methodology. The map illustrates that chalcopyrites and cadmium telluride emerge as the most suitable technologies in 47.12% of the national territory. Following closely behind is amorphous silicon, covering 30.45%, while monocrystalline and polycrystalline silicon account for 22.43%. The primary objective of this paper is to guide the proper selection of solar panel technology types that align optimally with Mexico’s climatic conditions. This strategic approach aims to strengthen the planning and viability of photovoltaic solar energy projects nationwide.

Advancing Hydrogen: A Closer Look at Implementation Factors, Current Status and Future Potential

This review article provides a comprehensive analysis of the hydrogen landscape, outlining the imperative for enhanced hydrogen production, implementation, and utilisation. It places the question of how to accelerate hydrogen adoption within the broader context of sustainable energy transitions and international commitments to reduce carbon emissions. It discusses influencing factors and policies for best practices in hydrogen energy application. Through an in-depth exploration of key factors affecting hydrogen implementation, this study provides insights into the complex interplay of both technical and logistical factors. It also discusses the challenges of planning, constructing infrastructure, and overcoming geographical constraints in the transition to hydrogen-based energy systems. The drive to achieve net-zero carbon emissions is contingent on accelerating clean hydrogen development, with blue and green hydrogen poised to complement traditional fuels. Public–private partnerships are emerging as catalysts for the commercialisation of hydrogen and fuel-cell technologies, fostering hydrogen demonstration projects worldwide. The anticipated integration of clean hydrogen into various sectors in the coming years signifies its importance as a complementary energy source, although specific applications across industries remain undefined. The paper provides a good reference on the gradual integration of hydrogen into the energy landscape, marking a significant step forward toward a cleaner, greener future.

Testing the waters: founding team composition and search heuristics in academic entrepreneurial ventures

Abstract Entrepreneurial action often stems from individual judgment about the value potential of market opportunities. Where entrepreneurs direct their search for and evaluate profitable opportunities has long received scholarly consideration. Attention has been increasingly directed toward how search is conducted, with a distinction between “cognitive” search, where actors are driven by a prior belief about the linkage between actions and outcomes (i.e., “learning-before-doing”) and “experiential search,” in which the solution must be realized through experimentation, trial-by-error, or “learning-by-doing.” We examine founders’ experiential search for market applications in uncertain technological environments. In doing so, we seek to uncover how founder background, experience, and depth of knowledge affect the firm’s degree of experiential search. We examine a sample of technology-oriented start-ups founded by researchers from six major US research universities to investigate the role of experiential search in university technology commercialization. In our context of academic entrepreneurship, we find that founding teams that draw from multiple disciplinary perspectives in selecting a market application to pursue exhibit a broader cognitive map of the technological landscape and thus expend more effort in the experiential search process than do teams with less varied backgrounds. Conversely, teams that include individuals with prior commercial experience conduct less experiential search, although this evidence is less strong. The inclusion of students appears to lead to greater experiential search by the founding team. Our findings add new understanding to the application of search heuristics by entrepreneurial firms in technology commercialization.

An assessment of the application of catalyst preheating prior to engine cold start to improve the filtration performance of CDPF on particulate emissions

The catalytic diesel particulate filter (CDPF) is an effective technology for reducing particle emissions. However, during engine startup, especially in cold start conditions, notable particle emissions are observed at the CDPF outlet. These emissions are attributed to combustion deterioration during startup and the low temperature of the aftertreatment catalyst. Addressing this challenge, this study investigated the effectiveness of rapidly preheating the diesel oxidation catalyst (DOC) and CDPF substrate temperatures before engine start to enhance particle removal during cold starts. Experimental results indicated that CDPF filtration efficiency during cold start was lower compared to hot start conditions, with a clean CDPF exhibiting very low efficiency due to minimal particle deposition. Substrate temperature preheating of either the DOC or CDPF was found to improve CDPF filtration efficiency for particles during cold start, albeit with a concurrent increase in emissions of particles smaller than 50 nm. Notably, a combination of a 250 °C DOC with a 22 °C CDPF yielded the most significant reduction in particle emissions, particularly for particles under 50 nm. Given that the DOC shares the same material composition as the CDPF but has a smaller volume that requires less energy for heating, preheating the DOC emerges as a more energy-efficient strategy. These findings underscore the need for more comprehensive studies on catalyst preheating to further the commercialization of technologies that effectively reduce cold start particle emissions, aligning with increasingly stringent future emission regulations.

Small-scale desalination and atmospheric water provisioning systems in water-scarce vulnerable communities: status and perspectives

ABSTRACT Small-scale desalination and atmospheric water provisioning systems can be vital for supplying drinking water in water-scarce areas. However, their potential to support vulnerable communities in such regions has not been fully assessed. Through an in-depth comprehensive review of 111 peer-reviewed publications from 1992 to 2023 and commercial technologies, this study shows significant knowledge gaps on implementing those systems in water-scarce vulnerable communities. To address knowledge gaps, research and implementation should align with local socio-economic, institutional and cultural contexts involving supportive policies, funding mechanisms, risk analysis, human resources, participatory approaches and consideration of community needs.

Solar spectral management in space using lanthanide-based downshifting layers

Photovoltaic (PV) cells are still the most used energy generation devices for aerospace applications. Although multijunction solar cells represent the standard commercial technology for powering spacecraft, spacecraft companies are still using Si-based PV cells to decrease the cost of satellites at the expense of efficiency and energy generation losses. One of the limitations on solar energy conversion is the mismatch between the solar spectrum and the absorption of the PV technology in use. Thus, strategies to overcome this have been proposed, namely the use of luminescent downshifting layers (DSLs) which are very promising to shape the incident sunlight. In this sense, downshifting materials with absorption in the UV/blue spectral region have been privileged considering the solar spectrum in space environments (AM0 solar spectrum), in which the UV component is larger than that on Earth surface (AM1.5 solar spectrum). Here, we propose the use of Eu3+-doped di-ureasil organic-inorganic hybrid materials as DSLs to be used on large area Si-based PV cells (∼0.1 m2) for space applications. Electrical measurements on the PV cell, done before and after the deposition of the DSLs, confirm the positive effect of the coatings on the device performance, with a relative increase on the generated electrical power of ∼2.6 %. Here, we report, for the first time, a DSL specifically designed for space applications and with the largest active area reported so far.

Experimental demonstration of coupled differential oscillator networks for versatile applications.

Oscillatory neural networks (ONNs) exhibit a high potential for energy-efficient computing. In ONNs, neurons are implemented with oscillators and synapses with resistive and/or capacitive coupling between pairs of oscillators. Computing is carried out on the basis of the rich, complex, non-linear synchronization dynamics of a system of coupled oscillators. The exploited synchronization phenomena in ONNs are an example of fully parallel collective computing. A fast system's convergence to stable states, which correspond to the desired processed information, enables an energy-efficient solution if small area and low-power oscillators are used, specifically when they are built on the basis of the hysteresis exhibited by phase-transition materials such as VO2. In recent years, there have been numerous studies on ONNs using VO2. Most of them report simulation results. Although in some cases experimental results are also shown, they do not implement the design techniques that other works on electrical simulations report that allow to improve the behavior of the ONNs. Experimental validation of these approaches is necessary. Therefore, in this study, we describe an ONN realized in a commercial CMOS technology in which the oscillators are built using a circuit that we have developed to emulate the VO2 device. The purpose is to be able to study in-depth the synchronization dynamics of relaxation oscillators similar to those that can be performed with VO2 devices. The fabricated circuit is very flexible. It allows programming the synapses to implement different ONNs, calibrating the frequency of the oscillators, or controlling their initialization. It uses differential oscillators and resistive synapses, equivalent to the use of memristors. In this article, the designed and fabricated circuits are described in detail, and experimental results are shown. Specifically, its satisfactory operation as an associative memory is demonstrated. The experiments carried out allow us to conclude that the ONN must be operated according to the type of computational task to be solved, and guidelines are extracted in this regard.