Search Results (1,493)

The photoelectrochemical splitting (PEC) of water provides a direct route to converting solar energy into storable chemical fuels. When illuminated, a semiconductor photoelectrode can absorb light and generate electron-hole pairs, which participate in interfacial redox reactions at the semiconductor-electrolyte junction. Therefore, to achieve high-performance PEC, photoelectrodes with optimized optical absorption and charge have been explored. This review analyzes recent fabrication strategies used to design photoelectrodes for the PEC dissociation of water. Physical fabrication techniques, including pulsed laser deposition, magnetron sputtering, and physical vapor deposition, allow for precise control of film thickness, crystallinity, and defect density, critical parameters for efficient charge transport. Typically, in physical methods, reported photocurrent densities span from ~10⁻² to 10¹ mAcm⁻², depending on the semiconductor material, nanostructure design, and interfacial engineering strategies. Chemical synthesis methods, such as hydrothermal growth, successive ion layer adsorption and reaction, and microemulsion techniques, provide greater compositional flexibility and enable controlled doping, surface functionalization, and the formation of nanostructured morphologies. Finally, hybrid fabrication strategies integrate physical and chemical processes within a single synthesis framework to combine structural precision with compositional tuning capabilities. These approaches enable the development of advanced architecture such as heterojunctions, core–shell nanostructures, and catalyst-modified interfaces, which enhance light absorption and optimize interfacial transfer. Furthermore, theoretical and computational tools are here analyzed as complementary approaches that guide the rational design and optimization of photoelectrochemical materials and devices. Full article

Conventional phenolic-resin-based carbon fiber paper (CFP) typically suffers from low mechanical strength, poor toughness, insufficient pore interconnectivity, and a reliance on extreme high-temperature graphitization to attain high conductivity. This study employs a novel melamine-hexamethylenediamine (MH) thermosetting resin as the binder to fabricate MH resin-based CFP (MHCFP). Through the synergistic effects of robust interfacial bonding, triazine-ring-induced low-temperature formation of sp² carbon clusters, and nitrogen doping, the MHCFP achieves comprehensive performance superiority over the phenol-formaldehyde (PF)-based CFP (PFCFP) at moderate carbonization temperatures (500–700 °C): MHCFP exhibits superior toughness, tensile strengths of 23–45 MPa (vs. PFCFP’s 8–18 MPa), and in-plane resistivity of 24–39 mΩ·cm (vs. PFCFP’s 54–83 mΩ·cm). Furthermore, MHCFP possesses a highly open macroporous structure (porosity > 78%), ensuring excellent gas permeability and water management capability. This work presents a promising low-temperature strategy for developing high-performance CFP, showing great potential for next-generation proton exchange membrane fuel cell gas diffusion layers. Full article

Structural optimization of the cathode flow field is a viable approach to homogenize multi-physical field distributions and boost the output of air-cooled proton exchange membrane fuel cells (PEMFCs). This work develops a three-dimensional non-isothermal model to systematically evaluate the performance of graded flow channel designs. The results indicate that the graded structure promotes fluid transport in the central zone, thereby improving oxygen distribution uniformity at the gas diffusion layer/catalyst layer (GDL/CL) interface. Compared to the traditional parallel flow channel (with an average oxygen mass fraction of 0.051% and a uniformity index of 0.779), this configuration yields a 6.4% increase in the average oxygen mass fraction and a 0.96% enhancement in distribution uniformity. However, increased gradient flow reduces the flow velocity within the channels and raises the operating temperature, posing challenges for water and thermal management. The curved channel design, featuring longer channels at the ends and shorter channels in the center, compensates for the uneven air supply caused by the fan, thus balancing the flow distribution. Among the tested configurations, the 10° curved structure exhibits optimal performance, achieving the best compromise between gas distribution and liquid water removal. It effectively promotes oxygen diffusion and uniform water distribution, significantly alleviating mass transfer polarization and yielding a more uniform interface temperature distribution due to evaporative cooling. Both excessively small and large curvature angles lead to performance degradation, primarily due to inadequate water removal and flow separation, accompanied by excessive pressure drop, respectively. In contrast, the 10° curved channel strikes an optimal balance, offering significant advantages in overall cell performance and water–thermal management, which provides critical guidance for optimizing PEMFC flow field designs. Full article

The use of resource-saving technology in road construction material production is a current problem, the solution of which will allow us to increase the environmental and economic efficiency of the road construction industry. Nowadays, secondary raw materials are widely used in highway construction, obtained both from the waste of old road construction materials and collected from other industries. During asphalt production, up to 90% of raw materials can be replaced by reclaimed asphalt pavement (RAP). This technology requires residual binder modification to reduce the negative impact on the technological and operational asphalt concrete properties. On the other hand, the use of rubber crumbs or granules obtained from the disposal of old car tires in asphalt–concrete mixtures is widespread. However, some types of car tires cannot be used as raw materials to produce an effective modifier. Truck tires and tires from special vehicles are suitable for use as a modifier for asphalt–concrete mixtures. Tires designed for passenger cars do not contain enough polymer. As an experiment on asphalt–concrete mixture production using secondary resources only, a testing facility was developed. The testing facility uses hot gas obtained by burning automobile tires in a special oven as a heat source. Rubber residues from the recycling of automobile tires are used as fuel, which cannot be used to produce rubber powder or granules. RAP obtained by cold milling of the pavements of city and public roads was used as the object of the research. When studying the characteristics of the asphalt–concrete-mixture-based binder, it was found that the sulfur compounds present in the composition of hot gases change the properties of the binder, leading to a serious deterioration in the technological characteristics of asphalt–concrete mixtures. The asphalt–concrete mixture obtained during RAP processing is characterized by a narrow temperature range in which it can be laid and compacted to the required density values. After laying the pavement, quality control revealed a significant variation (the number of air voids ranged from 0.8 to 5.5%) in the average density of samples taken from the compacted layer. In addition, there were significant violations of the longitudinal evenness of the finished coating. Experiments were carried out to extract the binder from asphalt–concrete mixtures before and after regeneration. The physico-mechanical and rheological characteristics were studied and qualitative analysis of the binder was realized by IR spectroscopy. The data obtained allow us to establish the mechanism of how sulfur-containing gases influence the bitumen binder’s properties in asphalt mixtures. Additionally, the features of thermo-oxidative degradation occurring during the hot recycling of asphalt–concrete mixtures were established. A justification is also given for the need to use anti-aging modifiers to restore the properties of the residual binder. Full article

Various types of turbine engines have been chosen as the primary power source of the long-endurance unmanned aerial vehicles (UAVs) because of their high propulsive efficiency and low specific fuel consumption. To ensure the healthy operation of UAV turbine engines, rotor unbalance should be monitored and constrained to a preset limit. This paper proposes an efficient and physically interpretable method to achieve rotor unbalance monitoring. This method enables the frequency response function (FRF) to inform the neural network design, bringing the physics-informed convolutional neural network (PICNN). Firstly, the FRF gives a qualitative judgment of the axial positions of dominant faulty parts. Then, the following subnet proceeds to achieve quantitative identification. This method is demonstrated on a series of numerical cases and on a twin-disk rotor-bearing-casing experimental setup with anisotropic supporting stiffness. This setup is representative of engine installation status on the UAV platform. The results show that the PICNN can achieve higher precision compared to pure data-driven or model-based benchmarks. The PI layer does not require a high-fidelity model that generates responses identical to the actual ones. The robustness against modeling errors in stiffness and damping ratios is demonstrated. The achieved relative errors are less than 1.5% under various experimental datasets. Full article

High-temperature Solid Oxide Fuel Cells (SOFCs) typically operate under conditions involving repeated thermal cycling. The transient temperature rise during thermal cycling directly affects the stress distribution within the SOFC structure, particularly inducing non-uniform thermal stresses in the electrolyte layer. This can readily lead to cracking and fracture of the SOFCs, potentially degrading overall system performance. Therefore, investigating the effects of cyclic thermal loading on structural stress distribution is essential for optimizing SOFC design. To this end, this study developed a coupled thermo-chemo-mechanical finite element analysis for a planar tubular SOFC. The model is employed to analyze the influence of thermal impact on the thermal stress distribution within the cell structure under multiple thermal cycling conditions. The results indicate that both the transient temperature rise during SOFC operation and the number of thermal cycles significantly affect the peak stress in the electrolyte layer and the overall performance stability of the cell. By optimizing the geometric configuration of the flat-tubular and the transient temperature rise during thermal cycling, the thermal stress field distribution in the electrolyte can be improved. These findings provide theoretical guidance for optimizing the design and engineering application of high-temperature SOFCs. Full article

To address the corrosion protection issues for hot components of high-end equipment in extreme service environments, the C276 alloy coating was deposited on the surface of 304 stainless steel via high-velocity air fuel (HVAF) spraying. The extreme conditions of 1000 °C temperature, an atmosphere containing 6% HCl, and a flow rate of 30 m/s were simulated in the study using a high-temperature airflow corrosion erosion device. The C276 coating and the 304 stainless steel substrates were subjected to a corrosion test for 25 min. The surface phase composition, element distribution, corrosion product characteristics, and cross-section structure of the samples before and after corrosion were systematically analyzed by means of a scanning electron microscope, an energy dispersive spectrometer, and an X-ray diffractometer. The mechanism of high-temperature chlorination corrosion was deduced through thermodynamic and kinetic analysis. The results show that compared with 304 stainless steel, the C276 alloy coating exhibits better corrosion resistance in an extremely high-temperature environment containing HCl, and the average weight gain and growth rate of the corrosion layer were lower. The main corrosion products on the C276 coating surface are Fe₂O₃, FeO, FeCl₂, NiO, and Cr₂O₃, among which the oxides of Ni and Cr form a continuous and dense protective oxide layer that effectively inhibits the intrusion of corrosive media. The high-temperature HCl corrosion follows the ‘chlorination–oxidation’ cycle mechanism, and Cl₂ plays a catalytic role in the reaction and accelerates the corrosion process. Full article

Electric vehicles (EVs) represent a key pathway toward reducing greenhouse gas emissions and fossil fuel dependence. Although significant advances have been achieved in energy storage technologies for EVs, a structured comparative assessment that jointly evaluates batteries, supercapacitors, and their hybridisation remains lacking. This review addresses that gap by systematically comparing lithium-ion, lead-acid, and nickel-based batteries with electrochemical double-layer capacitors (EDLCs), pseudocapacitors, and hybrid capacitors across ten performance and sustainability criteria. A literature-informed scoring framework, supplemented by sensitivity analysis under alternative weighting scenarios, is employed to rank the technologies. Particular attention is given to Hybrid Energy Storage Systems (HESS), which combine the high energy density of lithium-ion batteries with the high power density and long cycle life of supercapacitors. The review synthesises evidence that HESS can improve overall energy efficiency by up to 20% and extend battery lifetime by 30–50%, thereby reducing raw-material extraction, electronic waste, and lifecycle cost. Second-life pathways and circular-economy implications are discussed in depth. The findings demonstrate that neither batteries nor supercapacitors alone can satisfy the full spectrum of EV energy demands; instead, their integration within HESS offers the most balanced, sustainable, and economically viable solution. This work provides actionable insights for engineers, policymakers, and stakeholders engaged in next-generation sustainable mobility. Full article

Extreme hydro-meteorological events are intensifying under climate change, disproportionately disrupting last-mile healthcare in flood-prone geographies. In this study, flood-adaptive primary care clinics (FAPCCs) integrated with islandable smart microgrids and a rapid-deploy medical technology stack (MedTech) are developed and evaluated to ensure continuity of essential services (triage, maternal and child health, vaccination cold-chain, minor procedures, diagnostics, and telemedicine) during fluvial, pluvial, and coastal flooding. Evidence on resilient health facilities, microgrid architectures, distributed energy resources, and modular clinical systems is presented in a multi-layer systems design: (1) a modular, amphibious, and elevatable clinic chassis; (2) a photovoltaic–battery–diesel hybrid system with demand-aware energy management; (3) redundant connectivity long-term evolution/fifth-generation, satellite, and very high frequency; (4) a rapid-deploy MedTech kit including point-of-care diagnostics, low-temperature cold-chain, negative-pressure isolation, and sterilization modules; and (5) flood-aware logistics using unmanned aerial vehicle/unmanned surface vehicle. A mixed-integer linear programming sizing is formulated and dispatched with a continuity-of-care reliability metric that couples energy availability to clinical throughput. Simulation across three archetypal sites (peri-urban delta, inland riverine, coastal estuary) shows that FAPCCs achieve the service availability of higher than 99.5% across 7-day grid outage scenarios while reducing fuel use by 62–81% relative to diesel-only baselines, maintaining vaccine temperatures within 2–8 °C with <0.1% thermal excursion time, and sustaining telemedicine quality of service with <150 ms median uplink latency in hybrid networks. A life-cycle cost analysis indicates a 7.1–9.8 year discounted payback from fuel displacement and avoided service loss. Deployment playbooks and policy guidance are also proposed for Ministries of Health and Disaster Agencies in monsoon-impacted regions. Full article

This paper reviews research on energy management strategies (EMSs) for fuel-cell hybrid ships and introduces a “topology–strategy coupling” analytical framework, dividing system topology into two layers: energy-unit composition and DC-bus interface topology. It also introduces key concepts, such as EMS-independent dispatchability and the dominant DC-bus voltage-regulation unit. Based on this framework, the paper explains why certain strategies are easier to implement, tune, and validate under specific interface structures by considering the impact of interface topology on hybrid system efficiency and typical EMS constraints. It presents a unified four category EMS taxonomy, treating hybrid EMSs as a distinct class, and provides cross-category comparisons of different strategies. Additionally, it discusses the consistency and validation challenges when learning-based strategies transition from simulation to onboard deployment and further synthesizes mainstream approaches for integrating lifetime/health considerations into EMSs and their corresponding degradation modeling. Furthermore, the paper conducts a quantitative synthesis of relevant studies from 2016 to 2025, statistically summarizing and presenting the distributional characteristics of energy-unit composition, strategy categories, commonly used methods, validation approaches, and the inclusion of lifetime/health factors. In doing so, it uses data to describe the current state of research and identifies the key challenges and future research directions. Full article

Perfluorinated sulfonic acid ionomer (PFSAI) dispersions are widely used for fabrication of ion-conducting membranes and catalyst layers for hydrogen fuel cells. The conformation and concentration of PFSAIs affect the properties of the final product and depend on the liquid phase in dispersion. Here we present a novel method of preparing water/alcohol dispersions based on Nafion and Aquivion PFSAI by using a high-pressure homogenizer. The proposed route is faster and much safer and allows achieving higher PFSAI concentrations in comparison with the autoclave technique used for commercial dispersion preparation. The comparison of dispersion viscosity and PFSAI aggregate size was performed for both techniques and demonstrated similar values. Analysis of the morphology of membranes obtained from different dispersions by the casting method revealed differences in structure, which disappeared after annealing. These results highlight an important novel method of preparing PFSAI dispersions and the use of membrane morphology analysis for membrane quality evaluation. Full article

Previous research indicates that WC-12Co contents above 60 wt.% in feedstock powders for cermet coatings impair adhesion and wear resistance. This study characterizes NiCrFeSiAlBC coatings—unreinforced or reinforced with 65 wt.% or 85 wt.% WC-12Co—applied via high-velocity oxy-fuel (HVOF) spraying onto stainless steel substrates under controlled parameters. It quantifies the influence of high carbide volume fractions within the NiCrFeSiAlBC matrix on microstructure and tribomechanical performance. Microstructural analysis revealed uniformly distributed cermet layers featuring dissolved reinforcements and WC hard phase formation, with minimal W₂C crystallization. Elevated WC-12Co incorporation promoted densification and reduced porosity. Vickers microhardness tests (HV 0.3) demonstrated increased hardness upon WC-12Co addition, attributable to finer particle sizes, lower porosity, and the presence of WC phases alongside crystallographic refinements. Under dry reciprocating sliding conditions, friction coefficients and wear volumes decreased markedly. Consequently, the coating with 85 wt.% WC exhibited the best mechanical and tribological properties. Full article

The policymakers of Bangladesh have been mapping the energy mix to shift its high dependency on fossil fuels to sustainable energy; wind energy is addressed as a highly potential option. A feasible site selection process is essential for wind power plant establishment; thus, this study aims to identify potential areas for the sustainable development of large-scale wind plants by considering socio-economic, safety and environmental factors. In this study, two techniques of multi-criteria analysis (MCA), analytical hierarchy process (AHP) and ratio scale weighting (RSW), were incorporated with geographic information system (GIS) to select the optimal area in Bangladesh. This study considers fifteen sub-criteria under four main criteria, namely, socio-economy, geology, ecology, and climatology. AHP and RSW assign suitable weights to the sub-criteria based on their significant impact on the plant. GIS analyzes spatial data layers and produces suitability maps with the following categories: 5—most suitable, 4—suitable, 3—moderately suitable, 2—unsuitable, 1—completely unsuitable, and 0—excluded area. The final suitability map was generated using suitability maps of AHP and RSW. Finally, a combination of the final suitability map and the wind speed suitability map provide a total suitable area of 1595.8293 km². This could produce 2.96 GW power with 1418 wind turbines and be able to reduce 4,992,346.42 tons of CO₂ emissions annually (calculated using a reference turbine). The study was uniquely carried out at a 150 m hub height, and integration of AHP and RSW for weight cross-validation was performed for the first time in large-scale wind plant siting in Bangladesh. The findings of the study can be helpful for decision-makers in developing large-scale wind power plants. Full article

The accelerating transition toward carbon neutrality necessitates the synergistic integration of power and hydrogen systems to mitigate renewable intermittency; however, coordinating regulatory policies with the operational flexibility of these coupled systems remains a critical challenge under deep uncertainty. Motivated by this gap, this study develops a bilevel carbon price-coupled optimization framework for integrated power–hydrogen systems, aiming to coordinate environmental policy design with operational scheduling under deep uncertainty. The upper-level model represents the decision-making of a market regulator that determines the optimal carbon price and emission allowances to maximize overall social welfare, while the lower-level model captures the coordinated operation of electricity and hydrogen subsystems that minimize total dispatch cost, including renewable utilization, electrolyzer conversion, and fuel-cell recovery.To address stochastic variations in renewable generation and load demand, a Distributionally Robust Optimization (DRO) formulation is introduced using Wasserstein ambiguity sets, ensuring decision feasibility against worst-case probability distributions. The bilevel structure is efficiently solved via a Benders–Column-and-Constraint Generation (CCG) algorithm, which decomposes policy and operation layers into tractable subproblems with provable convergence. Case studies on a 33-bus integrated power–hydrogen network demonstrate that the proposed framework effectively balances economic efficiency and carbon reduction. Results show that the optimal carbon price of approximately 45 $/tCO₂ achieves a 27% emission reduction with only a 9% cost increase, revealing a near-optimal social welfare equilibrium. Hydrogen subsystems operate flexibly, with electrolyzer utilization increasing by 30% and storage cycling deepening by 15%, enabling enhanced renewable absorption. Sensitivity analyses confirm that the DRO layer reduces operational risk by 4% compared with stochastic optimization, validating robustness against distributional shifts. The study provides a rigorous and computationally efficient paradigm for policy-coordinated decarbonization, highlighting the synergistic role of carbon pricing and cross-energy scheduling in the next generation of resilient low-carbon energy systems. Full article

Colistin sulfate (COL), a critical last-line antibiotic, poses a severe environmental threat due to its persistence and role in spreading mobile resistance genes. This study introduces a novel quaternary Ni-Co-Zn-Al layered double-hydroxide/activated carbon composite (Q-LDH/AC) for highly efficient COL remediation. The composite’s unique architecture, revealed through comprehensive characterization, enables an exceptional adsorption capacity of 952.52 mg·g⁻¹ under optimal conditions (pH 7, 55 °C), a value that significantly surpasses those reported for most previous adsorbents. The process was spontaneous and endothermic, with kinetics and isotherms best described by the pseudo-second-order and Langmuir–Freundlich models, respectively, indicating a complex mechanism dominated by chemisorption on both homogeneous and heterogeneous sites. A key innovative feature is the successful regeneration and reusability of the composite, which retained over 70% efficiency after five cycles, enhancing its potential for practical, cost-effective water treatment applications. The thermodynamic parameters (ΔG° = −8140.68 kJ/mol, ΔH° = +61.22 kJ/mol) indicate that the reaction is spontaneous and endothermic. The interaction mechanism of COL on Q-LDH/AC can be deduced by FT-IR including hydrogen bonding, π-π bonding, electrostatic interactions, and surface complexation. Beyond mere regeneration, this work demonstrates a pioneering circular economy strategy by repurposing the spent COL-laden adsorbent not as waste, but as a high-performance electrocatalyst. In direct urea fuel cell tests, this electrode achieved a superior and stable current density of 45.63 mA/cm² for Q-LDL/AC, substantially outperforming the pristine Q-LDH/AC/COL (206.63 mA/cm²) and highlighting how the captured pollutant enhances functionality. This dual-purpose approach successfully closes the loop, transforming the environmental liability of antibiotic-laden waste into a valuable resource for energy applications. With a production cost of 2.755 USD/g, this work presents not only a highly effective adsorbent but also a transformative, circular strategy that simultaneously addresses water pollution and energy recovery. These findings offer a promising dual-purpose solution for mitigating the environmental spread of antibiotic resistance through a sustainable cycle that enables efficient antibiotic removal from wastewater while simultaneously converting the captured pollutant into a useful energy resource. Full article