Transport Mechanism Research Articles

Advancements in P3HT:PCBM solar cells through experimental and simulated techniques

Organic solar cells are a promising alternative in photovoltaics due to their low manufacturing cost and flexibility. In this study, we developed an organic solar cell of structure (ITO/PEDOT:PSS/P3HT:PCBM/Al) where the active layer is represented by P3HT:PCBM. Experimental studies revealed that this layer has an energy gap of 1.9 eV and a good absorption coefficient of 3×105cm−1 . Using analytical and experimental methods based on (J–V–T) curves, we extracted the key parameters of our device, including parasitic resistances ( Rs and Rsh ), ideality factor (n), and Schottky potential barrier ( ϕB) at different temperatures. Also the charge transport mechanism in our junction is identified in this study. We then used simulation to evaluate the performance of our solar cell, obtaining an initial efficiency of 2.13%, in line with experimental results from other research. Our results confirm the feasibility of our theoretical approach, with performance consistent with previous work. However, by introducing an electron transport layer layer (PFN-Br or PDINO), we were able to improve efficiency up to 4.25%. These results highlight the importance of optimising intermediate layers to maximise the efficiency of organic solar cells.

Electrical characteristics and trap signatures for Schottky barrier diodes on 4H-SiC, GaN-on-GaN, AlGaN/GaN epitaxial substrates

The forward and reverse current transport mechanisms, temperature dependence of Schottky barrier height (SBH) and ideality factor, barrier inhomogeneity analysis, and trap parameters for Schottky barrier diodes (SBDs) fabricated on 4H-SiC, GaN-on-GaN and AlGaN/GaN epitaxial substrates are reported. High SBH is identified for Ni/4H-SiC (1.31 eV) and Ti/4H-SiC (1.18 eV) SBDs with a low leakage current density of <10−8 A cm−2 at −200 V. Thermally stimulated capacitance detects the well-known Z1/2 electron trap at E C—0.65 eV in both 4H-SiC SBDs, while an additional deep-level trap at E C—1.13 eV is found only in Ni/4H-SiC SBDs. The vertical Ni/GaN SBD exhibits a promising SBH of 0.83 eV, and two electron traps at E C—0.18 eV and E C—0.56 eV are identified from deep-level transient Fourier spectroscopy. A peculiar two-diode model behavior is detected at metal/GaN/AlGaN/GaN interface of high-electron mobility transistor (HEMT); the first diode (SBH-1 of 1.15 eV) exists at the standard Metal/GaN Schottky junction, whereas the second diode (SBH-2 of 0.72 eV) forms due to the energy difference between the AlGaN conduction band and the heterojunction Fermi level. The compensational Fe-doping-related buffer traps at E C—0.5 eV and E C—0.6 eV are determined in the AlGaN/GaN HEMT, through the drain current transient spectroscopy experiments.

Advances in low-temperature solid oxide fuel cells: An explanatory review

This review article explores recent advancements and potential advantages of low-temperature solid oxide fuel cells (LT-SOFCs), offering a comprehensive overview of critical developments in the field. It highlights the significance of utilizing oxygen ion conducting electrolytes such as La0.8Sr0.2Ga0.8Mg0.2O3–type (LSGM) perovskties and yttria-stabilized zirconia (YSZ) in LT-SOFCs, emphasizing their role in facilitating efficient oxygen transport at lower temperatures. Furthermore, the review discusses the importance of electrode tailoring at the nanoscale using techniques like sol-gel and pulsed laser deposition (PLD), which have been shown to enhance the oxygen reduction reaction (ORR) at the cathode, thereby improving overall cell performance. One of the key focal points of the review is the exploration of perovskite structures and their imperative characteristics in LT-SOFCs. Specifically, it elucidates how oxygen defects within perovskites contribute to the migration of oxygen ions, consequently augmenting electrical conductivity within the cell. This discussion underscores the significance of understanding the fundamental principles governing ion transport mechanisms in electrolyte materials, which is crucial for the development of next-generation LT-SOFCs with improved efficiency and performance. Moreover, the review highlights recent advancements in the fabrication of nanoscale electrolyte films, which have shown promising results in reducing series resistance and enhancing cell performance at lower temperatures. Techniques such as atomic layer deposition (ALD), and spark plasma sintering (SPS) are discussed in the context of fabricating these nanoscale membranes, underscoring their potential for revolutionizing LT-SOFC technology. Overall, this review consolidates recent research findings and technological advancements in the field of LT-SOFCs, shedding light on the novel approaches and strategies employed to overcome existing challenges and propel the development of more efficient and practical fuel cell systems. By synthesizing key insights and highlighting future research directions, this review serves as a valuable resource for researchers and engineers working towards the advancement of LT-SOFC technology.

Advancements in black titanium dioxide nanomaterials for solar cells: a comprehensive review

AbstractOver the past decade, black titanium dioxide (B-TiO2) has garnered considerable attention within the scientific community due to its exceptional properties in optoelectronic and photovoltaic applications. This review offers a thorough examination of the synthesis, characteristics, and utilization of B-TiO2 nanomaterials in solar cell technologies. It underscores the pivotal role played by B-TiO2 in bolstering light absorption, facilitating charge separation, and optimizing charge transport mechanisms within solar cell architectures. Notable research endeavors are highlighted, showcasing the strides made in enhancing solar cell efficiency through the incorporation of B-TiO2. Furthermore, this review delves into the challenges inherent in the utilization of B-TiO2, including considerations of stability, scalability, and manufacturing methodologies, thereby stressing the imperative for refined synthesis techniques. Environmental concerns related to B-TiO2 are also addressed, underscoring the significance of evaluating its ecological footprint and advocating for sustainable deployment practices. Moreover, the review elucidates the future prospects of B-TiO2 in solar energy conversion, emphasizing innovations in device design and novel applications while championing environmentally conscious utilization practices. Serving as a comprehensive resource, this review is poised to empower researchers and practitioners alike, fostering deeper insights and facilitating advancements in the realm of B-TiO2 nanomaterials within the domain of solar cells.

Molecular Insights of an Avian Species with Low Oxygen Affinity, the Crystal Structure of Duck T-State Methemoglobin.

Hemoglobin (Hb) is the key metalloprotein within red blood cells involved in oxygen transportation from lungs to body cells. The heme-iron atom inherent within Hb effectuates the mechanism of oxygen transportation and carbon dioxide removal. Structural investigations on avian Hb are limited when compared with the enormous work has been carried out on mammalian Hb. Here, the crystal structure of T-state methemoglobin (T-metHb) from domestic duck (Anas platyrhynchos), a low oxygen affinity avian species, determined to 2.1Å resolution is presented. Duck T-metHb crystallized in the orthorhombic space group C2221 with unit cell parameters a = 59.89, b = 109.42 and c = 92.07Å. The final refined model with R-factor: 19.5% and Rfree: 25.2% was obtained. The structural analysis reveals that duck T-metHb adopts a unique quaternary structure that is distinct from any of the avian liganded Hb structures. Moreover, it closely resembles the deoxy Hb of bar-headed goose, a high oxygen-affinity species. Besides the amino acid αPro119 located in the α1β1 interface, a unique quaternary structure with a constrained heme environment is attributed for the intrinsic low oxygen-affinity of duck Hb. This study reports the first protein crystal structure of low oxygen-affinity avian T-metHb from Anas platyrhynchos.

Biomass-Derived Carbon Materials for Advanced Metal-Ion Hybrid Supercapacitors: A Step Towards More Sustainable Energy

Modern research has made the search for high-performance, sustainable, and efficient energy storage technologies a main focus, especially in light of the growing environmental and energy-demanding issues. This review paper focuses on the pivotal role of biomass-derived carbon (BDC) materials in the development of high-performance metal-ion hybrid supercapacitors (MIHSCs), specifically targeting sodium (Na)-, potassium (K)-, aluminium (Al)-, and zinc (Zn)-ion-based systems. Due to their widespread availability, renewable nature, and exceptional physicochemical properties, BDC materials are ideal for supercapacitor electrodes, which perfectly balance environmental sustainability and technological advancement. This paper delves into the synthesis, functionalization, and structural engineering of advanced biomass-based carbon materials, highlighting the strategies to enhance their electrochemical performance. It elaborates on the unique characteristics of these carbons, such as high specific surface area, tuneable porosity, and heteroatom doping, which are pivotal in achieving superior capacitance, energy density, and cycling stability in Na-, K-, Al-, and Zn-ion hybrid supercapacitors. Furthermore, the compatibility of BDCs with metal-ion electrolytes and their role in facilitating ion transport and charge storage mechanisms are critically analysed. Novelty arises from a comprehensive comparison of these carbon materials across metal-ion systems, unveiling the synergistic effects of BDCs’ structural attributes on the performance of each supercapacitor type. This review also casts light on the current challenges, such as scalability, cost-effectiveness, and performance consistency, offering insightful perspectives for future research. This review underscores the transformative potential of BDC materials in MIHSCs and paves the way for next-generation energy storage technologies that are both high-performing and ecologically friendly. It calls for continued innovation and interdisciplinary collaboration to explore these sustainable materials, thereby contributing to advancing green energy technologies.

On the spatio-temporal dynamics of cavitating turbulent shear flow over a microscale backward-facing step: A numerical study

The influence of cavitation on the mean characteristics and unsteady behavior of turbulent separated flows was comprehensively investigated in this study over a microscale backward-facing configuration at the Reynolds number (ReD) of 7440. The computational approach took both compressibility and finite mass transfer (Thermodynamic non-equilibrium) into account, to accurately capture the effects of shock waves, as well as to capture baroclinic phenomena on vortex dynamics within the turbulent separated flow. The compressibility effects were handled by using appropriate equation of states for each phase and for the mixture. Phase-change was considered through a transport equation for the vapor volume fraction, allowing for finite mass transfer contributions. Additionally, a wall adaptive large eddy simulation (LES) approach was utilized for simulating turbulent structures and their effects. The findings reveal that vapor development diminishes the mean growth rate of the shear layer and delays its reattachment to a longer distance from the step. Moreover, analysis of Reynolds normal and shear stresses, as well as the root mean square (RMS) of pressure fluctuations, demonstrates that the formation and collapse of vapor packets significantly influence turbulence decay and production in the second half of the shear layer and reattachment. It was also observed that both mean pressure and pressure fluctuations increased in vicinity of the reattachment region when cavitation was present, which was attributed to the condensation and collapse events. Spectral analysis further indicates the emergence of two dominant low frequency modes, linked to the displacement of the reattachment point. In the presence of cavitation, the frequencies associated with dominant Power Spectral Densities (PSDs) were smaller than those in the absence of cavitation. Additionally, each of these low frequencies corresponded to a specific vapor transport mechanism within the Turbulent Separation Bubble (TSB). Furthermore, it is shown that cavitation leads to a significantly higher spectral energy of high frequency fluctuations within the reattachment region in comparison to the condition where cavitation is absent. This can be attributed to the frequent collapse of bubbles in this region. At the end, we employed Spectral Proper Orthogonal Decomposition (SPOD) for modal analysis. This method offers valuable insights into the coherent structures and associated frequencies that arise in both the presence and absence of cavitation, which provides a deeper understanding of the effect of cavitation on the coherent structures and their dynamics.

Evaluating hydrogen embrittlement susceptibility of operated natural gas pipeline steel intended for hydrogen service

Green hydrogen produced by renewable energy sources is expected to play an important role as a decarbonized energy carrier. It can be transported cost-effectively over long distances by pipelines. Hydrogen transport through existing natural gas pipeline networks is supposed to be prospective. However, a possible degradation of gas pipeline steels as a result of their long-term operation should be taken into account in assessing the prospects of using the existing gas network for hydrogen transportation safely. In this study, hydrogen embrittlement susceptibility of low-carbon pipeline steel in the as-received state and after long-term operation is investigated. The influence of long-term operation on the microstructure, mechanical properties, and fracture mechanism of steel is assessed, considering the direction of cutting the specimens relative to the pipe axis. The electrolytic hydrogen pre-charging process with different intensities is used to analyze the influence of absorbed hydrogen on the mechanical behaviour of steel by tensile tests of uncharged and hydrogen-charged specimens. The as-delivered steel is not prone to hydrogen embrittlement after moderate hydrogen charging, while the operated one is sensitive to it. Metallographic and fractographic analyses revealed a crucial role of non-metallic inclusions in the hydrogen embrittlement of steel, which depended on its technical state and hydrogen charging conditions. Moderate hydrogen charging led to intergranular embrittlement of steel, while intensive − to transgranular embrittlement, indicating different mechanisms of transport of hydrogen absorbed by the metal.

Stabilization of structure and channel height of two-dimensional montmorillonite membrane for efficient ion separation

As a new type of separation material, two-dimensional membrane has attracted wide attention due to its special transport mechanism. However, due to the hydration swelling of montmorillonite nanosheets, there are still challenges in preparing two-dimensional membrane with stable channel structure and fixed interlayer spacing. In order to overcome the problems caused by swelling, this study used polyvinyl alcohol and polyacrylic acid to stabilize the channel structure of two-dimensional membranes. Moreover, the crosslinking between Fe3+ and montmorillonite nanosheets was proposed to fix the interlayer spacing of two-dimensional membrane. It is found that various polymers had different effects on the mechanical property of two-dimensional membrane. The addition of polyvinyl alcohol and polyacrylic acid can significantly improve the tensile strength of the membrane. And the introduction of them reduces the hydrophilicity of the membrane surface, thus improving the stability of the membrane in water. In addition, the interlayer cations affect the stability of interlayer spacing of the membrane in water. After crosslinking the membrane with Fe3+, the interlayer spacing is fixed and can be maintained at about 0.94 nm in water for a long time. When a certain dosage of polyvinyl alcohol and PAA are added into the membrane and the crosslinking conditions are suitable, two-dimensional membrane has good selectivity to Li+ and Mg2+ in high Mg/Li ratio brine. Inspired by the natural ion exchange properties of montmorillonite, this study found a new method for inhibiting the hydration swelling of two-dimensional membrane and realizing precise control of interlayer spacing.

Effect of Graphene Oxide Nanomaterials on the Durability of Concrete: A Review on Mechanisms, Provisions, Challenges, and Future Prospects.

This review focuses on recent advances in concrete durability using graphene oxide (GO) as a nanomaterial additive, with a goal to fill the gap between concrete technology, chemical interactions, and concrete durability, whilst providing insights for the adaptation of GO as an additive in concrete construction. An overview of concrete durability applications, key durability failure mechanisms of concrete, transportation mechanisms, chemical reactions involved in compromising durability, and the chemical alterations within a concrete system are discussed to understand how they impact the overall durability of concrete. The existing literature on the durability and chemical resistance of GO-reinforced concrete and mortar was reviewed and summarized. The impacts of nano-additives on the durability of concrete and its mechanisms are thoroughly discussed, particularly focusing on GO as the primary nanomaterial and its impact on durability. Finally, research gaps, future recommendations, and challenges related to the durability of mass-scale GO applications are presented.

Enhanced Sampling Molecular Dynamics Simulations Reveal Transport Mechanism of Glycoconjugate Drugs through GLUT1.

Glucose transporters GLUT1 belong to the major facilitator superfamily and are essential to human glucose uptake. The overexpression of GLUT1 in tumor cells designates it as a pivotal target for glycoconjugate anticancer drugs. However, the interaction mechanism of glycoconjugate drugs with GLUT1 remains largely unknown. Here, we employed all-atom molecular dynamics simulations, coupled to steered and umbrella sampling techniques, to examine the thermodynamics governing the transport of glucose and two glycoconjugate drugs (i.e., 6-D-glucose-conjugated methane sulfonate and 6-D-glucose chlorambucil) by GLUT1. We characterized the specific interactions between GLUT1 and substrates at different transport stages, including substrate recognition, transport, and releasing, and identified the key residues involved in these procedures. Importantly, our results described, for the first time, the free energy profiles of GLUT1-transporting glycoconjugate drugs, and demonstrated that H160 and W388 served as important gates to regulate their transport via GLUT1. These findings provide novel atomic-scale insights for understanding the transport mechanism of GLUT1, facilitating the discovery and rational design of GLUT1-targeted anticancer drugs.

Defect/disorder correlated modification of transport properties from hopping to tunneling processes in BaTiO3–LaFeO3 solid solution

Crystal structure, bandgap, and the changes in the charge conduction mechanisms in ceramics are interrelated, and the underlying physics unifies all these different phenomena. The experimental and theoretical evaluation of the electronic properties of the solid solution of (1 − x)BaTiO3–(x)LaFeO3 (x = 0, 0.015, 0.031, 0.062) is attempted in this work. Bandgap was observed to be tunable with La/Fe doping from 3.2 eV (x = 0) to 2.6 eV (x = 0.06), while the lattice disorder was found to increase. A theoretical assessment confirms a considerable shift of valence band maxima and conduction band minima with an introduction of additional defect states within the bandgap. Electron localization was also confirmed theoretically with doping. Such changes in the electronic properties were experimentally confirmed from dielectric/AC - conductivity/impedance spectroscopy studies. From different transportation models, hopping is a preferred mechanism in the less distorted BaTiO3. However, a large polaron tunneling process can be justified for the doped samples at lower temperatures. Only at higher temperatures, a small polaron tunneling can be justified for the doped samples. The transportation is affected by the grain boundaries as much as the grains themselves. A complete analysis using Nyquist plots reveals the competing contributions of these regions to the transportation mechanism and is correlated to the disorder/distortions in the lattice in terms of the formation of oxygen vacancies.

Numerical simulation of heat transfer and nanoparticle transport in a nanofluid within a tumour surrounding a blood vessel

A Newtonian nanofluid containing suspended nanoparticles can substantially improve heat transfer due to enhanced energy transport mechanisms. This theoretical study investigates heat and mass transfer in biological tissues using such a nanofluid under a magnetic field. These properties have promising medical and engineering applications. The nonlinear governing equations were transformed into ordinary differential equations using similarity variables and numerically solved with MATLAB boundary value problem solver bvp4c, subject to appropriate boundary conditions. Results demonstrated increasing the heat source parameter dramatically raised tumor interstitial temperature. This heating, along with improved nanoparticle accumulation within the tumor due to the thermal effects, are together essential for effective hyperthermia treatment. The model provides new insights into tuning heat and mass transport mechanisms in biological tissues via nanofluids for therapeutic applications. Therefore, the findings of this study may improve the efficacy of thermal therapy in treating cancer.

Regulating the Ion Transport in the Layered V2O5 Electrochromic Films with Tunable Interlayer Spacing

AbstractUnveiling the ion transport mechanism to design and explore efficient and stable ion transport pathways for high‐performance transition metal oxide (TMO)−based electrochromic materials is highly desired yet challenging. Herein, this study has demonstrated that the interlayer spacing of layered vanadium penoxide (V2O5) films can be tuned by inserting different amounts of lithium−ion (Li+) within host V2O5 material, as well as adjusting ion transport behavior and electrochromic performance. These results show that V2O5 with a small amount of ion insertion delivers a stable ion transport process and electrochromic properties. Increasing the amount of inserted Li+ will enlarge the interlayer spacing, which provides abundant active sites and efficient ion transport channels, and thus reversible and rich color variation of yellow−green−blue−olive green−orange is realized. Nevertheless, an excess of ion insertion results in the crystal structure collapse and cyclic stability degradation. These findings give a rationale for the evolution of electrochromic properties during different electrochemical reaction stages. This work provides considerable insight into the ion transport behavior within the layered V2O5 films, which gives fundamental theoretical guidance for developing and designing superior layered TMO electrochromic materials.

Performance study of low temperature air heated rock bed thermal energy storage system

AbstractOne of the primary types of sensible heat storage systems in drying applications is the packed rock bed. However, to create large‐scale heat storage systems for industrial use, one must comprehend the hydrodynamic and effectiveness of the heat transport mechanism inside the bed. In this study, the thermal storage unit uses river rock as heat storage materials with equivalent particle diameters of 36 mm in bed 1 and 56 mm in bed 2. The rocks were stacked in a truncated cone‐shaped concrete wall section with an average diameter and depth of 1.1 m and 1.3 m, respectively and a volume of 2.32 m3. During the charging phase, two airflow configurations were used, one from the top with an air mass flow rate of 0.753 and 0.332 kg/m2‐s and the other from the bottom with an air mass flow rate of 0.955 kg/m2‐s. During the discharging phase, the entire flow configuration is from the bottom section. It was observed that the mass flow rate and particle equivalent diameter had an important effect on the thermal performance and behaviour of the rock bed during charging and discharging operations. Maximum efficiency was achieved with an airflow configuration provided from the bottom when charging at 0.955 kg/m2.s. Consequently, a sizable quantity of heat or energy (60 MJ) was retained. It was also observed that the relationship between air mass flow rate and particle size was significant, with smaller particles retaining more energy. When comparing bed 1 with bed 2 at this air mass flow rate, bed 1 stored 2.1 times more energy than bed 2. A wind tunnel experiment was used to measure the pressure drop in the packed rock bed. The pressure drop in the bed increases with an increase in particle Reynolds number and decreases with an increase in particle size. Rock bed heat transfer coefficient and Nusselt number were calculated using the correlation that has already been established in the literature smaller particles showed higher heat transfer coefficients and lower Nusselt numbers. This is due to the increase in particle‐to‐particle interaction and larger particle surface areas. For a given Reynolds number, the Nusselt number increases with the size of the rock particle.

Suppression of current-induced membrane discharge of bipolar membranes by regulating ion crossover transport

Bipolar membranes (BPMs) exhibit the unique capability to regulate the operating environment of electrochemical system through the water dissociation-combination processes. However, the industrial utilization of BPMs is limited by instability and serious energy consumption. The current-induced membrane discharge (CIMD) at high-current conditions has a negative influence on the performance of anion-exchange membranes, but the underlying ion transport mechanisms in the BPMs remain unclear. Here, the CIMD-coupled Poisson-Nernst-Planck (PNP) equations are used to explore the ion transport mechanisms in the BPMs for both reverse bias and forward bias at neutral and acid-base conditions. It is demonstrated that the CIMD effect in the reverse-bias mode can be suppressed by enhancing the diffusive transport of salt counter-ions (Na+ and Cl−) into the BPMs, and that in the forward-bias mode with acid-base electrolytes can be suppressed by matching the transport rate of water counter-ions (H3O+ and OH−). Suppressing the CIMD can promote the water dissociation in the reverse-bias mode, as well as overcome the plateau of limiting current density and reduce the interfacial blockage of salt co-ions (Cl−) in the anion-exchange layer in the forward-bias mode with acid-base electrolytes. Our work highlights the importance of regulating ion crossover transport on improving the performance of BPMs.

Effect of polarization on tunnelling electroresistance in ferroelectric tunnel junctions

High-quality epitaxial BiFeO3 (BFO) films were grown on (001)-, (110)- and (111)-oriented Nb:SrTiO3 (NSTO) substrates by pulsed laser deposition. The type of domain structure can be modulated using BFO ferroelectric films with different crystalline orientations. The ON/OFF ratios obtained in (001)-, (110)- and (111)-oriented Au/BFO/NSTO ferroelectric tunnel junctions (FTJs) are 6 × 103, 3 × 104 and 2 × 105, respectively. Analysis of the I–V curves of tunnelling current and average BFO ferroelectric barrier height proves that the polarization intensity of the BFO films modulates both the ferroelectric barrier and the Schottky barrier profile, which further influences the electronic tunnelling probability in BFO FTJs. This work will be useful for further study on achieving a giant ON/OFF ratio and developing insights into the barrier profile and transport mechanism of metal/ferroelectric/semiconductor-type FTJs.

Aqueous AlCl3/ZnCl2 solution room-induced the self-growing strategy of expanded topological network for cellulose/polyacrylamide-based solid-state electrolytes

The green synthesis strategy for cellulose-containing hydrogel electrolytes is significant for effectively managing resources, energy, and environmental concerns in the contemporary world. Herein, we propose an all-green strategy using AlCl3/ZnCl2/H2O solvent to create cellulose/polyacrylamide-based hydrogel (AZ-Cel/PAM) with expanded hierarchical topologies. The aqueous AlCl3/ZnCl2 facilitates the efficient dissolution of cellulose at room temperature, and the dispersed Al3+-Zn2+ ions autocatalytic system catalyzes in-situ polymerization of acrylamide (AM) monomer. This expands the AM network within the cellulose framework, forming multiple bonding interactions and stable ion channels. The resulting hybrid hydrogel exhibits improved mechanical properties (tensile strength of 56.54 kPa and compressive strength of 359.43 kPa) and enhanced ionic conductivity (1.99 S/m). Furthermore, it also demonstrates excellent adhesion, freeze resistance (−45 °C), and water retention capabilities. Quantum simulations further clarify the mechanical composition and ion transport mechanism of AZ-Cel/PAM hydrogels. The assembled supercapacitor with the hydrogel electrolyte, demonstrates an ideal area-specific capacitance of 203.80 mF/cm2. This all-green strategy presents a novel approach to developing sustainable energy storage devices.

Highly sensitive rhodamine B dye-based electrochemical sensor for lactose detection

Lactose (LAC) is the main disaccharide sugar found in milk and dairy products, making it easily accessible as a food source. In addition to its importance for human and animal health, LAC concentrations serve as a biomarker of milk quality. In this study, we reported the detection of LAC using a highly sensitive electrochemical sensor based on rhodamine B (RhB) dye. The prepared RhB-based sensor exhibited excellent characteristics, including a straightforward manufacturing technique, cost-effectiveness, and exceptional sensitivity. We conducted a comparative analysis of the electrochemical response of the novel RhB-based sensor, evaluating its electrochemical performance across varying LAC concentrations and when different analyte materials (glucose, fructose, and maltose) were employed. The proposed analytical method was utilized to determine LAC using an electrochemical RhB-based sensor under optimal experimental conditions. As a result, it was experimentally observed that high sensor sensitivity of RhB based sensor against LAC was inversely proportional to the impedance value and directly proportional to conductance which corolated with the transport mechanism of RhB.

The migration of hydrogen in sedimentary basins

Understanding the mechanisms of large-scale, subsurface hydrogen migration is essential for natural hydrogen exploration and for hydrogen storage assessment. The unique properties of hydrogen make the timescales of hydrogen migration within geological basins vary from thousands of years to days. Within the shallow Earth, diffusive and advective transport mechanisms are dependent on a wide range of parameters, including geological structure, microbial activity and subsurface environmental factors (e.g. salinity, temperature and pressure). In this study, we review the nature and timescale of hydrogen migration in geological basins. We also review the mechanisms and timescales of hydrogen migration within diffusive, advective and biologically moderated systems within the shallow Earth. We calculate maximum vertical velocity for several key rock types, including sandstone and micrite, and discuss the importance of capillary pressure in controlling the mode of hydrogen migration in sedimentary rocks. Finally, we discuss the potential application of causal analyses methods to constrain complex processes in hydrogen systems and assess the challenges of conventional reservoir modelling for hydrogen migration.