Surface Engineering Research Articles

GFP Farnesylation as a Suitable Strategy for Selectively Tagging Exosomes.

Exosomes are small extracellular vesicles (EVs) constituting fully biological, cell-derived nanovesicles with great potential in cell-to-cell communication and drug delivery applications. The current gold standard for EV labeling and tracking is represented by fluorescent lipophilic dyes which, however, importantly lack selectivity, due to their unconditional affinity for lipids. Herein, an alternative EV fluorescent labeling approach is in-depth evaluated, by taking advantage of green fluorescent protein (GFP) farnesylation (GFP-f), a post-translational modification to directly anchor GFP to the EV membrane. The performance of GFP-f is analyzed, in terms of selectivity and efficiency, in several typical EV experimental setups such as delivery in recipient cells, surface engineering, and cargo loading. First, the capability of GFP and GFP-f to label exosomes was compared, showing significantly higher GFP protein levels and fluorescence intensity in GFP-f- than in GFP-labeled exosomes, highlighting the advantage of directly anchoring the GFP to the EV cell membrane. Then, the GFP-f tag was further compared to Vybrant DiD lipophilic dye labeling in exosome uptake studies, by capturing EV intracellular fluorescence in a time- and concentration-dependent manner. The internalization assay revealed a particular ability of GFP-f to monitor the uptake of tagged exosomes into recipient cells, with a significant peak of intensity reached 12 h after administration by GFP-f but not Vybrant-labeled EVs. Finally, the GFP-f labeling capability was challenged in the presence of a surface modification of exosomes and after transfection for siRNA loading. Results showed that both procedures can influence GFP-f performance compared to naïve GFP-f exosomes, although fluorescence is importantly maintained in both cases. Overall, these data provide direct insight into the advantages and limitations of GFP-f as a tagging protein for selectively and accurately tracking the exosome route from isolation to uptake in recipient cells, also in the context of EV bioengineering applications.

Innovative surface engineering of sustainable polymers: Toward green and high-performance materials

The development of sustainable polymers is critical to the progression of greener manufacturing processes, especially for the additive manufacturing technologies of fused deposition modeling (FDM). The study aims to explore potential application surface engineering techniques that enhance the performance of these sustainable polymers within the context of FDM. Various surface modification methods, such as plasma treatment, chemical etching, and UV irradiation, were utilized on biodegradable and recycled polymers, with the treatment process conducted under controlled conditions. Mechanical testing was done using a Tinius Olsen universal testing machine, with surface morphology analyzed through scanning electron microscopy. The outcome indicated that the tensile strength of polylactic acid improved by 15% with plasma treatment, while the thermal stability of recycled polyethylene terephthalate improved by 12% with chemical etching. Surface engineering developments on various techniques will be reviewed, particularly in optimizing them within FDM processes for different types of polymers. Different surface modifications will be compared here, analyzing aspects such as adhesion, endurance, and more overall performance. This comparison provides a fundamental outlook into the relationship between surface treatment and polymer performance, paving the way for optimization of FDM processes in sustaining material applications. These findings serve as further guidance toward making additive manufacturing much more sustainable and efficient through advanced surface engineering. The numerical improvement of material properties observed in the study will aid in further endeavors towards achieving sustainability and efficiency in additive manufacturing.

Efficacy Assessment of Sulfated Flavanol Functionalized Silver Nanoparticles against MCF-7 Breast Cancer

Aim: The present research work aims to formulate a cost-effective and less toxic drug for specific and selective delivery at the tumor site. Background: Existing therapeutics, such as chemo, surgery, etc., for fast-paced MCF-7 breast cancer, still face challenges, especially due to their toxic side effects. The unique properties of metal nanoparticles embedded in anti-oxidant plant polymers have sparked great interest in the formulation of less toxic-targeted drugs for cancer cure. Objective: The present work aims to synthesize a targeted formulation of colloidal nanosilver by surface engineering of silver nanoparticles using plant polymers in electrolytic deposition technique, developed indigenously at the institute lab. Methods: A current is passed through an elctrolyte, AgNO3, which splits it into ions. The positive ions of Ag deposit over LDPE wrapped carbon cathode and negative ion, NO3, is liberated. Ag+ ions get capped in-situ. These surface-modified silver nanoparticles formulate a colloidal solution. UV-visible and FTIR spectroscopy, TEM-EDX, and XRD were used to validate asprepared formulation and in vivo human tumor xenograft model in NOD-SCID mouse for efficacy against MCF-7 breast cancer. Results: The as-synthesized formulation consists of pure spherical poly-dispersed silver nanoparticles of average size 5.4 nm, coated with sulphated flavanols. The efficacy evaluation reported that it significantly, T/C = 0.53, reduced tumor volumes with a 100% survival rate and change in animal body weight <4 gms. Conclusion: The as-synthesized formulation can be used as a potential neo-adjuvant or adjuvant drug along with existing therapeutics for MCF-7 breast cancer, significantly reducing the toxicity and cost.

Highly stable, antiviral, antibacterial cotton textiles via surface engineering.

The unprecedented pandemic has highlighted the need for textiles that rapidly inactivate pathogens to protect public health. However, how to achieve rapid, effective and durable pathogen inactivation with the minimum antimicrobial dose loading has become a major challenge for cotton fabric modification. Here, a surface engineering cotton fabric (Co-CMC@Cu2+) was prepared by grafting carboxymethyl chitosan (CMC) onto cotton fabric and then loading with Cu2+ via coordination. The Co-CMC@Cu2+ with minimal copper ion dosage achieved rapid inactivation, excellent comfort, good biosafety, and durability. Specifically, Co-CMC modified with 12.5 mmol/L copper ion solutions achieved impressive bacterial reduction (BR) rates of 94.3 % and 89.3 % against E. coli and S. aureus, respectively, within 10 min of contact. Moreover, the bacteria were completely eradicated after 2 h of continuous contact. Additionally, Co-CMC@Cu2+ achieved excellent phage reduction (PR) rates of 98.9 % and 100 % against phi6 and phi-x174 bacteriophages, respectively, within 30 min of exposure, highlighting its potential for viral inactivation. Furthermore, Co-CMC@Cu2+ demonstrated exceptional durability for pathogen inactivation, with BR and PR values above 80 %, even after 150 washing cycles. This novel antimicrobial and antiviral cotton fabric will be a promising candidate textile to protect public health during a pandemic.

Simultaneous structure and surface engineering of metal-organic framework derived LiNi0.5-xFe2xMn1.5-xO4 cathode material for improving high voltage performance of lithium-ion batteries

This study presents a novel material synthesis approach utilizing a terephthalic acid-based metal-organic framework as a precursor and employing an ethanol-assisted hydrothermal treatment to produce high-performance Fe-doped LiNi0.5Mn1.5O4 (LNMO) cathode material. This strategy yields a well-crystallized spinel structure with uniformly distributed transition metal ions. Additionally, the appropriate quantity of Fe dopant can achieve the desired Mn3+/Mn4+ ratio, level of structural disordering, and crystal phase purity for Fe-doped LNMO. The synthesis process also aids in forming an amorphous Li2CO3 surface layer, approximately 1 nm thick, which protects the active material from excessive reaction with electrolyte. The typical Fe-doped LNMO cathode (S-05) exhibits superior performance compared to a commercialized LNMO counterpart. It delivers an initial discharge capacity of 135 mAh g-1 at 1 C with exceptional cycling stability over 500 cycles (capacity retention of 90%) under high voltage (5.0 V vs. Li+/Li). Furthermore, its rate capability significantly improves, with a capacity retention of 85% (5 C/0.2 C). This enhanced performance aligns with evidence of activated Ni2+/Ni3+/Ni4+ redox reactions and suppressed cathode electrolyte interphase resistance, leading to promoted Li+ diffusion. Moreover, it is found the cathode helps alleviate electrolyte degradation at high voltages by inhibiting the formation of singlet oxygen in the electrolyte.

The Expanded Phases Formed in Stainless Steels by Means of Low-Temperature Thermochemical Treatments: A Corrosion Perspective

Surface engineering of stainless steels using thermochemical treatments at low temperatures has been the subject of intensive research for enhancing the surface hardness of these alloys without impairing their corrosion resistance. By using treatment media rich in nitrogen and/or carbon, it is possible to inhibit chromium compound formation and obtain supersaturated solid solutions, known as expanded phases, such as expanded austenite or S-phase in austenitic stainless steels, expanded ferrite in ferritic grades, and expanded martensite in martensitic grades. These low-temperature treatments produce a significant increase in surface hardness, which improves wear and fatigue resistance. However, the corrosion behavior of the modified surface layers remains of paramount importance. In the international literature, many studies on this topic are reported, but the results are not always univocal, and there are still open questions. In this review, the corrosion behavior of the expanded phases and the modified layers in which they are present is critically analyzed and discussed. The relationships between the phase composition and the microstructure of the modified layers and the corrosion resistance are highlighted while also considering the different test conditions. Furthermore, corrosion test methods are discussed, and suggestions are given for improving the measurements. Finally, perspectives on future directions for investigation are suggested for encouraging further research.

Surface engineering-based S, N co-doped biochar for improved anaerobic digestion: Enhancing microbial-pollutant and inter-microbial electron transfer synergistic EPS protection

Enhancing extracellular electron transfer (EET) efficiency is crucial for improving the anaerobic digestion (AD) system's capability to treat recalcitrant wastewater. In this study, a novel S, N co-doped biochar (S-N-BC) was prepared through surface engineering to optimize EET within AD systems. The addition of S-N-BC significantly enhanced the performance of a mesophilic AD system treating Congo red wastewater, increasing the decolorization rate by 78%, COD degradation rate by 82%, and methane yield by 87% compared to the control. Additionally, the shock resistance of anaerobic granular sludge was improved, as evidenced by the formation of the protective extracellular polymeric substances (EPS) barrier and the enhanced activities of the electron transport system. Mechanistic analysis revealed that adding S-N-BC did not alter the Congo red decolorization pathway but significantly enriched various electrochemically active bacteria and established EET pathways between microbial-pollutant and inter-microbial. This significantly accelerated EET efficiency within the AD system, ensuring stable and efficient operation under challenging conditions. This study proposed a novel approach using S-N-BC to simultaneously enhance "dual-pathway EET" between microbial-pollutant and inter-microbial while constructing an EPS protective barrier, addressing the issues of low efficiency and fragile stability of AD systems for treating recalcitrant wastewater.

Digital Light Processing (DLP) 3D Printing Fabrication of Hydrophobic Meshes Incorporating Fluorinated and Silicone-Based Acrylates Combined with Surface Engineering: Comparison of Their Oil–Water Separation Efficiency

Digital Light Processing (DLP) 3D Printing Fabrication of Hydrophobic Meshes Incorporating Fluorinated and Silicone-Based Acrylates Combined with Surface Engineering: Comparison of Their Oil–Water Separation Efficiency

Surface engineering of paper via binary graphene inks for sustainable micro-supercapacitor with innovative architecture

Paper-based micro-supercapacitors (MSCs) are a vital on-chip micro-energy storage component for degradable and implantable electronics that are envisioned as the forerunner of sustainability revolutions. However, an easily-manipulated, macro-assembly proposal and innovative paper architecture to ameliorate the intrinsic topology surface and nonconducting feature remain challenging. In this work, a generalized surface assembly strategy is reported for controllably engineering a graphene-anchored monolithic network for the degradable metal-free paper MSCs. Devoid of insulating auxiliaries and multistep postprocessing (such as cryogenic assistance), the as-engineered paper electrodes essentially consist of unique conductive fiber layer featuring interconnected nanosheets and accumulated functionalized graphene layer based on micron-sized fibers, providing excellent flexibility and anti-aging properties. The multiscale capillary of cellulose fibers and effective space-charge of functionalized graphene ensure fast charge transport. Consequently, the resulting integrated paper MSCs deliver an impressive areal capacitance of 36.5 mF cm−2, high energy density of 3.25 μWh cm−2 and long-term cycling performance (66.4 % retention after 10 000 cycles), surpassing most previously reported paper-based MSCs. The new charge reservoir engineering on paper to fabricate sustainable energy storage system would open a novel available paradigm for the growing demand of portable and degradable electronics.

Biocompatibility and drug release kinetics of TiNbZrSn femtosecond laser-induced superhydrophilic structures

As load-bearing components, metallic implants are frequently used for orthopedic prostheses due to their superiority over conventional ceramic and polymeric biomaterials. Metal-based orthopedic implants have been subjected to various fabrication and treatment methods to enhance their biological activities at the host site. Modifying the structure, improving the hydrophilicity, and developing controlled-release drug delivery systems can improve cellular adhesion, proliferation, osseointegration, and differentiation. Ultrafast lasers have recently attracted interest in surface engineering. Laser surface structuring permits the alteration of sample topography, the chemical makeup of the surface, and the material physical properties. This study presents the surface modification of a TiNbZrSn shape memory alloy using a femtosecond laser to produce laser-induced periodic structures with better drug release than that of a pristine sample. We also present the in vitro cell viability and biocompatibility of the alloy system. All samples structured with femtosecond laser exhibited superhydrophilic nature with 0° contact angle. In addition, the laser structured surfaces showed cell viability above 80 % and minimal cytotoxicity towards human keratinocytes. Moreover, a well-defined hydroxyapatite layer developed on the laser structured surface. In general, the laser structuring process and the induced changes on the surface in terms of roughness and oxide formation result in slower drug release (up to 10 %) compared to pristine specimens.

3D printing of biomimetic hierarchical surface textures using L-PBF for improving tribological performance of Ti6Al4V alloy

Energy and material losses due to friction and wear during the use of materials bring about very serious costs in every sector. In order to minimize friction and wear losses of materials, different surface engineering applications are used, especially surface coatings, thermal, mechanical and thermochemical processes. On the other hand, it has been shown in recent years that the tribological properties of materials can be controlled by creating different types of biomimetic hierarchical patterns on the surface of materials. Therefore, this study investigates both the individual and the synergetic effects of both biomimetic surface textures and thermal oxidation process on the tribological performance of Ti6Al4 V alloy. For this purpose, hierarchical models were produced using the laser powder bed fusion (L-PBF) technique, which is one of the additive manufacturing methods. Snake skin, shark skin and tree frog models were used as biomimetic hierarchical models. Additionally, flat and random snake skin models were used to examine the effect of texture orientation. Moreover, thermal oxidation was carried out at 700 ⁰C for 2 h and 4 h and the wear tests were carried out using a reciprocation-type tribo-tester under dry and simulated body fluid (SBF) conditions. As the oxidation time increased, the hardness and surface roughness of the material increased. A significant improvement in the wear rate of biomimetic models was observed compared to the non-textured sample. Lower tribological performance was observed in the tree frog model (hexagonal geometry) compared to other biomimetic models due to the presence of sharp corners. In particular, the snakeskin model provided the best wear rate because it trapped wear residue and provided additional hydrodynamic pressure. The highest tribological performances for all samples were observed in the samples oxidized at 700 ⁰C for 4h.

Enhancing power density in D-mode GaN HEMT direct-current triboelectric nanogenerators through ICP-etched surface engineering

In the evolving landscape of energy harvesting, the refinement of friction properties in metal-semiconductor direct current triboelectric nanogenerators (MSDC TENGs) has garnered significant attention. While prior research predominantly concentrated on achieving superior performance in MSDC TENGs through material manipulation, structural adjustments, and friction mode optimization, there has been a noticeable dearth of investigations into surface engineering or modification of semiconductor materials. In this paper, the surface patterning of depletion mode GaN-based high electron mobility transistor (D-GaN HEMT) as friction materials is done by inductively coupled plasma etching method, involving both mechanism analysis and experimental exploration. Through modulation of etching depth and pattern density, a systematically arranged diamond pattern is created on the surface, augmenting surface roughness and charge density. Consequently, the surface-patterned D-GaN HEMT TENG achieves a maximum short-circuit current of 60 µA and a peak power density of 4.05 W/m², which is about 2.8 times greater than the pristine D-GaN HEMT TENG. Furthermore, the power supply capabilities of the surface-patterned D-GaN HEMT TENG are scrutinized, revealing its proficiency in capacitive charging and discharging. The successful activation of a deep ultraviolet LED underscores its potential applications in ultraviolet disinfection. This research holds substantial significance in optimizing the power generation efficiency and performance of MSDC TENGs employing D-GaN HEMT.

The Photophysics of Perovskite Emitters: from Ensemble to Single Particle.

Halide perovskite emitters are a groundbreaking class of optoelectronic materials possessing remarkable photophysical properties for diverse applications. In perovskite light emitting devices, they have achieved external quantum efficiencies exceeding 28%, showcasing their potential for next-generation solid-state lighting and ultra high definition displays. Furthermore, the demonstration of room temperature continuous-wave perovskite lasing underscores their potential for integrated optoelectronics. Of late, perovskite emitters are also found to exhibit desirable single-photon emission characteristics as well as superfluorescence or superradiance phenomena for quantum optics. With progressive advances in synthesis, surface engineering, and encapsulation, halide perovskite emitters are poised to become key components in quantum optical technologies. Understanding the underpinning photophysical mechanisms is crucial for engineering these novel emergent quantum materials. This review aims to provide a condensed overview of the current state of halide perovskite emitter research covering both established and fledging applications, distill the underlying mechanisms, and offer insights into future directions for this rapidly evolving field.

Insights on Prussian Blue Analogue Cathode Material Engineered with Polypyrrole Surface Protection Layer for Aqueous Rechargeable Zinc Metal Battery.

One of the key intricacies against using Prussian blue analogues (PBAs)in aqueous batteries is their gradual dissolution in aqueous electrolytes, resulting in inadequate cycling stability. Besides, the rate capability of PBAs is limited due to their poor electrical conductivity. To overcome these challenges, it is essential to tune the physical and chemical properties of PBAs at the nano regime without affecting the inherent charge storage properties, especially at high-voltage operating conditions. Through this work, a strategy is demonstrated to enhance the electrochemical performance of vanadium-based PBA (V-PBA) by surface engineering using a conducting polymer nano-skin (V-PBA/PPy) for aqueous zinc metal batteries. The polypyrrole (PPy) nano-skin over the V-PBA nanoparticles acts as an electron percolation path to ameliorate the poor electronic conductivity of the otherwise pristine V-PBA. Interestingly, the V-PBA with an optimized polypyrrole coating (V-PBA/PPy-2) exhibits an enhanced specific capacity (173 mAh g-1 at 0.10 A g-1) than the pristine V-PBA counterpart (80 mAh g-1) and 85% capacity retention up to 500 cycles. The DFT calculation confirms the synergistic interaction between PPy and V-PBA and the presence of PPy favors the adsorption of Zn.

Theoretical models from experiments on particle population in convective arrays

Studying suspensions of gold nanorods has provided valuable knowledge on variations in concentration and how nanoparticles behave. Analysis of UV–visible spectra has shown changes in both longitudinal and transverse peaks, indicating a reduction in nanoparticle absorption peaks as the nanoparticle concentration decreases in suspension. Furthermore, changes in droplet contact angles have elucidated a direct correlation between nanoparticle density and droplet dynamics, shedding light on the intricate interplay between concentration reduction and droplet behavior. Investigations into cetyltrimethylammonium bromide (CTAB-coated) gold nanorods have unraveled the complexities of depletion, electrostatic, and Van der Waals forces, offering valuable knowledge on the self-assembly mechanisms governing these nanomaterials. The examination of interactions within coffee stain rings has underscored the crucial role of nanoparticle density in nanostructure arrangements, influencing deposition patterns and contributing to a deeper understanding of volume fraction evolution in nanostructured systems. By establishing a quantitative framework for interpreting energy parameters and observing optimal fitting agreements with experimental data, this research provides a solid foundation for future endeavors aimed at elucidating nanomaterial behavior in suspended systems. This comprehensive overview lays the groundwork for tailored manipulation of gold nanorod properties, emphasizing the essential relationship between density and contact angle in shaping wetting phenomena and surface engineering practices.

Human-CoMo: A Combination of Cognitive Knowledge Engineering and Data Modelling for Human-Cyber-Physical Systems in Intelligent Manufacturing

Many cyber-physical systems face the challenge of appropriately integrating domain-specific human expert knowledge into the cyber part to create a shared sphere of knowledge and intelligent interactions between humans and the semi-autonomous technical system. Cognitive engineering contributes methods and insights into higher-order cognition that help to embed human knowledge in an appropriate way. The original research introduces a novel transdisciplinary framework called Human-CoMo, which demonstrates a systematic modelling process, different human perspectives, and the integration of expert knowledge at multiple hierarchical levels. Fundamental principles inspired by human cognition, such as conceptual chunking and knowledge precision, are characterised. Furthermore, it is shown how knowledge hierarchies can be methodically reflected in appropriate data analysis and modelling levels for small and big data applications including artificial intelligence approaches. Combined knowledge- and data-based modelling approaches offer more flexibility to integrate the strengths of humans and technology in a complementary way. The cognitive foundations and their computational reflections are outlined for the technical example process electroplating from the field of materials and surface engineering. The possibilities and limitations of integrating human knowledge through formalisation and implications for future forms of human-machine interaction are discussed.

Enhanced Low-Humidity Performance of Polymer Exchange Membrane Fuel Cells via Membrane Surface Engineering.

Polymer electrolyte membrane fuel cells (PEMFCs) play a pivotal role in meeting the energy needs of high-power applications such as construction and agricultural machinery and mobility. High-power operation often exacerbates problems associated with water management within the cell due to excessive water generation, affecting water distribution at the cathode and anode interfaces. Our research recognizes the importance of addressing challenges associated with the high-power operation of polymer electrolyte membrane fuel cells (PEMFCs) for use in high-power fuel cell applications. The introduction of surface-patterned membranes leads to overall performance enhancement and improved humidity stability, thereby mitigating critical issues related to high-power operation. The enhanced contact at the electrolyte/catalyst interface and the expanded three-phase interface contribute to better heat dissipation and water management, ultimately alleviating challenges associated with catalyst efficiency and water stability during high-power usage. Furthermore, the improved low-humidity performance and stability observed in our study leverage the excessive water generated during PEMFC low-humidity operation. This not only enhances overall performance but also presents an opportunity to improve efficiency by utilizing the excess water generated, potentially reducing the costs associated with humidification maintenance. Our findings highlight the potential of surface-patterned membranes to address both high-power and low-humidity challenges, offering a comprehensive solution for the optimal performance of PEMFCs in demanding applications such as construction and agricultural machinery, as well as in the field of mobility.

Surface Engineering of Copper Foam to Construct a Hierarchical Heterostructure for High Energy Efficient Supercapacitors.

As a unique pseudocapacitive material, the heterojunction-structured CuO@Cu combines the high conductivity of substrate Cu and the high capacity of active CuO together for structure-integral electrodes, however, its structural optimization and improved capacity are still the main challenges so far. In this study, an initial surface etching of copper foam (CF) is adopted to construct a primary heterostructure of CuO nanowires@CF (CuO NW@CF), and then, the surface decoration of CuO NW@CF via the deposition of cerium-2-methylimidazole based metal-organic frameworks (Ce-2MI) finally results in the current-collector-/binder-free electrodes of the hierarchical heterostructure Ce-2MI@CuO NW@CF. Compared to the structural properties of CuO NW@CF, both the introducing Ce-ion active sites and the enriched lattice oxygen vacancies cooperatively endow the pseudocapacitive electrodes of Ce-2MI@CuO NW@CF with a ultrahigh specific capacitance and excellent cycling stability. Within the potential window of 1.6 V, the asymmetric supercapacitor devices of activated carbon//Ce-2MI@CuO NW@CF acquire a high energy density of 56.8 Wh kg-1 at 725 W kg-1, which can light up a light-emitting diode (LED) bulb for 20 min. Therefore, constructing the hierarchically heterostructured Ce-2MI@CuO NW@CF is an effective approach to developing high-performance supercapacitors for potential application purposes.

The application of pressure-driven ceramic-based membrane for the treatment of saline wastewater and desalination–A review

Ceramic-based membranes, known for their stability, mechanical strength, and anti-fouling properties, have garnered significant attention for their application in treating saline wastewater and ion rejection. As a green technology, the preparation process of ceramic membranes does not need to use a large number of organic solvents, showing the characteristics of environmental friendliness. This review comprehensively examines recent advancements and optimization strategies in the preparation of ceramic membranes. The discussion encompasses both traditional fabrication methods and innovative techniques such as co-sintering, the introduction of sacrificial layers, and 3D printing. Additionally, the review delves into surface engineering design strategies, including functionalized modifications and the construction of new separation layers on ceramic supports. These advanced designs, such as polyamide/ceramic and graphene oxide/ceramic composite membranes, leverage the strengths of multiple materials, resulting in enhanced separation performance, mechanical strength, and resistance to chemical and thermal stress. The review also highlights the recent ceramic-based membranes applications in saline water treatment. Finally, the challenges and future prospects of ceramic-based membranes are discussed in detail.

Different surfaces of copper with single-atom doping for hydrogen evolution reaction in alkaline conditions

The advantages of Cu-based materials make it a potential catalyst for alkaline hydrogen production reactions (HER), but the inertness of pure Cu restricts its application. Thus, it is very meaningful to seek strategies to improve the catalytic activity. In this work, we designed the 15 modified Cu surface models by integrating single atom doping with surface engineering to be used to explore the catalytic activity of Cu surfaces in alkaline HER and the mechanism of effective adsorption and dissociation of water. The results indicated that the combination of surface engineering with single-atom doping can greatly activate the electro-catalysis activity of copper surface. All these 15 catalysts can effectively achieve hydrogen evolution in alkaline conditions, among which the H2O dissociation energy barriers of Cu(210)-Os and Cu(210)-Ru are just 0.47 eV and 0.60 eV, which are much lower than that of pure Pt(111). Thus, it is expected that Cu(210) doped with proper noble metal elements is an ultra-low-cost and ultra1-high-performance catalyst for alkaline HER. Meanwhile, Os and Ru-doped Cu(110) and Cu(211) surfaces also demonstrate remarkable alkaline HER activity compared with the metal catalysts that have been reported hitherto. These offer a novel concept and theoretical guidance to design cheaper and more efficient HER catalysts.