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Methanol steam reforming (MSR) is an attractive route for producing clean energy hydrogen. PdZn alloys are extensively studied as potential MSR catalysts for their stability and high CO2 selectivity. Here, we investigated the reaction mechanism using density functional calculations, mean-field microkinetic modeling (MF-MKM), and kinetic Monte Carlo (kMC) simulations. To overcome the over-underestimation of CO2 selectivity by log-kMC, an ads-kMC algorithm is proposed in which the adsorption/desorption rate constants were reduced under certain requirements and the diffusion process was treated by redistributing surface species each time an event occurred. The simulations show that the dominant pathway to CO2 at low temperatures is CH3OH → CH3O → CH2O → H2COOH → H2COO → HCOO → CO2. The ads-kMC predicted OH coverage is 2–3 times that of MF-MKM, while they produce similar coverage for other species. Analyses indicate that surface OH promotes the dehydrogenation of CH3OH, CH3O, and H2COOH significantly and plays a key role in the MSR process. The dissociation of water/methanol is the most important rate-limiting/rate-inhibiting step. The CO2 selectivity obtained by the two methods is close to each other and consistent with the experimental trend with temperature. Generally, the ads-kMC results agree with the MF-MKM ones, supporting the previous finding that kMC and MF-MKM predict similar results if the diffusion is very fast and adsorbate interactions are neglected. The present study sheds light on the MSR process on PdZn alloys, and the proposed scheme to overcome the stiff problems in kMC simulations is worthy of being extended to other systems. [ABSTRACT FROM AUTHOR]

Energy utilities play an important role in transitioning to a sustainable energy industry. Data on 8967 transactions by 19 European energy utilities from 1990 to 2019 illustrate when and how utilities invest in sustainable resources and divest traditional resources such as fossil-fuel plants. Utilities transitioning to sustainable energy have greater financial resources and experience with sustainability, are publicly owned, and access sustainable resources of international and inter-industry partners. Utilities adopt a diversified strategy of balancing sustainable and traditional resources. [ABSTRACT FROM AUTHOR]

In the pursuit of sustainable energy solutions, the development of materials with efficient hydrogen and methane storage capacities is imperative, particularly for advancing hydrogen-powered vehicles. Metal–organic frameworks (MOFs) have emerged as promising candidates to meet the stringent targets set by the Department of Energy for both hydrogen and methane storage. This study employs Grand Canonical Monte Carlo simulations to investigate the usable hydrogen and methane gravimetric and volumetric storage capacities of the recently synthesized SIGSUA. A comparative analysis encompasses the selected MOFs with similar metal compositions, those with comparable density and average pore radius, and classical benchmarks, such as IRMOF-15 and IRMOF-20, all evaluated at room temperature and moderate pressures ranging from 25 to 35 MPa. The results reveal that SIGSUA demonstrates noteworthy gravimetric and volumetric storage capacities for both hydrogen and methane, rivaling or surpassing those of the selected MOFs for analysis. These findings underscore the potential of SIGSUA in advancing clean energy storage technologies. [ABSTRACT FROM AUTHOR]

Heterogeneous photocatalysis is an important research problem relevant to a variety of sustainable energy technologies. However, obtaining high photocatalytic efficiency from visible light absorbing semiconductors is challenging due to a combination of weak absorption, transport losses, and low activity. Aspects of this problem have been addressed by multilayer approaches, which provide a general scheme for engineering surface reactivity and stability independent of electronic considerations. However, an analogous broad framework for optimizing light–matter interactions has not yet been demonstrated. Here, we establish a photonic approach using semiconductor metasurfaces that is highly effective in enhancing the photocatalytic activity of GaAs, a high-performance semiconductor with a near-infrared bandgap. Our engineered pillar arrays with heights of ∼150 nm exhibit Mie resonances near 700 nm that result in near-unity absorption and exhibit a field profile that maximizes charge carrier generation near the solid–liquid interface, enabling short transport distances. Our hybrid metasurface photoanodes facilitate oxygen evolution and exhibit enhanced incident photon-to-current efficiencies that are ∼22× larger than a corresponding thin film for resonant excitation and 3× larger for white light illumination. Key to these improvements is the preferential generation of photogenerated carriers near the semiconductor interface that results from the field enhancement profile of magnetic dipolar-type modes. [ABSTRACT FROM AUTHOR]

This document is a tribute to Dr. Wladyslaw Walukiewicz, a renowned scientist in the field of compound semiconductors, who passed away in 2022. Dr. Walukiewicz made significant contributions to multiple scientific topics throughout his career and brought together a global community of researchers. His work focused on understanding defects in semiconductors and their impact on material and device performance. The document highlights some of his key achievements, including his research on carrier mobilities, doping limits, band structures, and the discovery of the narrow band gap of InN. The document also mentions a special topic in the Journal of Applied Physics dedicated to Dr. Walukiewicz, which includes various papers that build on his concepts and insights. The authors of the document express their fond memories of Dr. Walukiewicz and his contributions to the scientific community. [Extracted from the article]

This study reviews available van der Waals- and Platteeuw-based hydrate models considering multiple occupancy of cavities. Small guest molecules, such as hydrogen and nitrogen, are known to occupy lattice cavities multiple times. This phenomenon has a significant impact on hydrate stability and thermodynamic properties of the hydrate phase. The objective of this work is to provide a comprehensive overview and required correlations for the implementation of a computationally sufficient cluster model that considers up to five guest molecules per cavity. Two methodologies for cluster size estimation are evaluated by existing nitrogen hydrate models showing accurate results for phase equilibria calculations. Furthermore, a preliminary hydrogen hydrate model is introduced and compared with the results of other theoretical studies, indicating that double occupancy of small sII cavities is improbable and four-molecule clusters are predominant in large sII cavities for pressures above 300 MPa. This work lays the foundation for further exploration and optimization of hydrate-based technologies for small guest molecules, e.g., storage and transportation, emphasizing their role in the future landscape of sustainable energy solutions. [ABSTRACT FROM AUTHOR]

The increasing demand for functional nanodevices in sustainable energy applications necessitates the development of innovative approaches. In this study, we present the fabrication and characterization of three-dimensional (3D) structures coated with titanium dioxide (TiO 2) nanorods (NRs). These novel devices are created through the integration of four distinct techniques, multi-photon lithography, post-thermal treatment, pulsed laser deposition, and an aqueous chemical growth, enabling their unique properties and functionalities in photocatalysis. The photocatalytic performance of the 3D devices is evaluated through the degradation of organic pollutants, such as methylene blue and stearic acid, showcasing their efficiency in reducing pollutant concentrations. The devices demonstrate a remarkable decomposition coefficient (k = 0.059 min − 1 ), highlighting their enhanced photocatalytic efficiency. Additionally, we propose a rapid fabrication technique using 3D holographic printing to create large-area TiO 2 -coated micro-structured photocatalytic devices at the mesoscale regime. This approach increases the active surface area, further enhancing the devices' photocatalytic capabilities. By combining additive micro-manufacturing, TiO 2 NR coating, and holographic printing, our work introduces a promising avenue for the development of advanced nanodevices with superior photocatalytic performance in sustainable energy applications. [ABSTRACT FROM AUTHOR]

Harnessing the boundless solar energy, photovoltaic cells emerge as pivotal players in the world's sustainable energy landscape. The efficiency of solar cells is intimately tied to the carrier properties influenced by defects and impurities within the sunlight-absorbing semiconductors. In this Perspective, we offer a brief overview of recent advances in exploring doping properties with a focus on three vital thin-film photovoltaic semiconductors: CdTe, CIGS, and halide perovskites. Our discourse encompasses their electronic band structure, intrinsic and extrinsic doping behaviors, defect-assisted nonradiative recombination losses, as well as promising strategies poised to enhance solar cell efficiency. Additionally, we discuss several lingering challenges associated with defects in the advancement of photovoltaic technologies. [ABSTRACT FROM AUTHOR]

Many experimental and theoretical studies on CH4–CO2 hydrates have been performed aiming at the extraction of CH4 as a relatively clean energy resource and concurrent sequestration of CO2. However, vague or insufficient characterization of the environmental conditions prevents us from a comprehensive understanding of even equilibrium properties of CH4–CO2 hydrates for this substitution. We propose possible reaction schemes for the substitution, paying special attention to the coexisting phases, the aqueous and/or the fluid, where CO2 is supplied from and CH4 is transferred to. We address the two schemes for the substitution operating in three-phase and two-phase coexistence. Advantages and efficiencies of extracting CH4 in the individual scheme are estimated from the chemical potentials of all the components in all the phases involved in the substitution on the basis of a statistical mechanical theory developed recently. It is found that although substitution is feasible in the three-phase coexistence, its working window in temperature–pressure space is much narrower compared to the two-phase coexistence condition. Despite that the substitution normally generates only a small amount of heat, a large endothermic substitution is suggested in the medium pressure range, caused by the vaporization of liquid CO2 due to mixing with a small amount of the released CH4. This study provides the first theoretical framework toward the practical use of hydrates replacing CH4 with CO2 and serves as a basis for quantitative planning. [ABSTRACT FROM AUTHOR]

The electric grid was designed to move large amounts of energy through space, but decarbonization goals will require it to also move energy through time--from days and seasons with a surplus of energy production to days and seasons with insufficient production. Long-duration energy storage technologies that can hold a large amount of electricity and distribute it over periods of many hours to days and even seasons will play a critical role in the clean energy transition. But creating an environment in which these nascent technologies can develop and thrive will require changes in how the grid is planned and built. [ABSTRACT FROM AUTHOR]

Piezo-photocatalysis is a "green" approach to decompose various pollutants using natural clean energy. Herein, a series of ZnSnO 3 /C nanofibers with excellent piezo-photocatalytic activities were reported. The XRD, TEM and SEM, as well as XPS measurements were carried out and the results indicate that ZnSnO 3 /C nanofibers with the orthorhombic phase were fabricated successfully. The UV–vis absorbance spectra, photocurrent response, EIS curves and photoluminescence characteristics indicate that the incorporated C decreases the band gap of ZnSnO 3 and improves separation efficiency of photoinduced charge-hole pairs, which results in higher catalytic activity of ZnSnO 3 /C nanofibers. The photocatalytic, piezocatalytic and piezo-photocatalytic activities were investigated by degrading diclofenac. The ZnSnO 3 /C‒0.3 ‰ has the highest reaction constant among the series of catalysts. The reaction constat of ZnSnO 3 /C‒0.3 ‰ in photocatalysis process (0.0185 min−1) is 2.15 times that of ZnSnO 3. The reaction constat of ZnSnO 3 /C‒0.3 ‰ in piezo-photocatalysis process (0.0549 min−1) is 2.97 times that of ZnSnO 3 /C‒0.3 ‰ in photocatalysis and 3.47 times that of ZnSnO 3 in piezo-photocatalysis (0.0158 min−1). The •OH and e− radicals are key roles for degrading diclofenac in catalysis processes. [ABSTRACT FROM AUTHOR]

Concerning environmental issues, including global warming and the reduction of hydrocarbon assets, the utilization of environmentally sustainable energy production is imperative nowadays. In this regard, water electrolysis is considered the most prominent and ecologically sustainable technique for the production of hydrogen. However, owing to its sluggish OER, designing electrode materials with remarkable efficiency becomes crucial for boosting the functioning of water electrolysis. In the present investigation, we successfully developed the SnSe catalyst incorporated into graphitic carbon nitride (g-CN) via a simple hydrothermal approach. The various approaches were used to characterize g-CN/SnSe nanocomposite. Meanwhile, g-CN/SnSe nanocomposite demonstrated exceptional catalytic properties for OER under 1.0 M alkaline electrolyte (KOH), which exhibited low overpotential (241 mV) to obtain ideal j (10 mA cm−2) and an exceptional stability (20 h). It also demonstrated a low onset potential (1.27 V), a significant electrochemical active surface area (ECSA) of 592.5 cm2 and an impressive Tafel value (38 mV dec−1), significantly superior to the pure SnSe nanomaterial. The observed improved performance can be attributed to enhanced morphological properties and significant surface area. The above-reported nanocomposite (g-CN/SnSe) shows great potential for OER and other electrochemical systems because of its numerous active sites, faster electron transfer process, exceptional durability and good electrical conductivity. [ABSTRACT FROM AUTHOR]

In the context of escalating global efforts to mitigate carbon emissions and explore sustainable energy resources, the transformation of CO2 into valuable chemicals and fuels via plasma technology has garnered significant attention. This study demonstrated a new pathway of CO2 conversion into CO and H2O2 via the bubble-enabled gas-liquid discharge driven by a nanosecond pulse. Results showed that the increased discharge frequency and larger pulse widths could enhance CO2 conversion rates and H2O2 yields, albeit potentially at the cost of reduced energy efficiency. Conversely, the rising time of pulse showed negligible impact on the process, whereas varying gas flow rates significantly altered CO and H2O2 yields, underscoring the nuanced influence of these parameters on the efficiency and selectivity of conversion processes. Through illuminating the dynamics of bubble discharge-assisted CO2 transformation, this study contributes to the broader understanding of gas-liquid discharge driven by nanosecond pulse, underlining its potential for addressing environmental and energy challenges. [ABSTRACT FROM AUTHOR]

A novel non-isolated high-gain DC–DC converter for green energy employment is presented and analyzed. The proposed converter comprises a switched capacitor cell, passive clamp circuit, coupled inductors, and voltage multiplier unit. An interleaved boost converter (IBC) is placed on the input side of the proposed design. The voltage multiplier unit (VMU) with the secondary windings of the coupled inductors is located on the load side. It is used to accomplish interleaved power storage. The leakage energy of coupled inductor is recirculated to the load side, and the reverse recovery problem of diodes is effectively suppressed. As a result, a low-on-state resistance power switch with a low voltage rating is employed and minimizing conduction losses. The presented topology is suitable for sustainable energy applications due to its low operating duty cycle, high voltage conversion ratio, and higher efficiency. The output voltage causes substantially low voltage stress on semiconductor switches and passive elements. This proposed paper deals with simulation, parameter selection, experimental design, results and discussion. The simulation is verified using MATLAB/Simulink with a DC voltage of 30–517 V. To validate the design analysis, a 1.5-kW experimental prototype is designed with a switching frequency of 10 kHz and attained an efficiency of 96.07%. [ABSTRACT FROM AUTHOR]

The film photocatalyst is easily recycled and has attracted the widely research interesting. Here the ferroelectric Hf 0.5 Zr 0 · 5 O 2 (HZO) thin film synthesized through the atomic layer deposition (ALD) method is used as a photocatalyst for the rhodamine B (RhB) dye decomposition under visible light irradiation. The photocatalytic RhB dye decomposition performances with or without an external magnetic field excitation provided by a commercial NdFeB magnet are experimentally characterized. With the increasing of the external direct-current (DC) magnetic field from 0 to 3000 Gs, the photocatalytic RhB dye decomposition ratio by HZO film obviously increases from 87.20 % to 98.17 %, which is attributed to the enhanced separation of the photo-induced positive and negative carrier due to the magnetic Lorentz effect. The magnetically-induced enhancement of photocatalysis in the ferroelectric HZO film, provides a method with these advantages of simple external excitation method, remarkable promotion effect and friendly-environment to enhance the dye decomposition ratio, and is potential in the practical application of photocatalytic dye wastewater treatment through harvesting the clean solar energy in future. [ABSTRACT FROM AUTHOR]

Renewable energy sources, such as wind, tide, solar cells, etc, are the primary research areas that deliver enormous amounts of energy for our daily usage and minimize the dependency upon fossil fuel. Paralley, harnessing ambient energy from our surroundings must be prioritized for small powered systems. Nanogenerators, which use waste energy to generate electricity, are based on such concepts. We refer to these nanogenerators as energy harvesters. The purpose of energy harvesters is not to outcompete traditional renewable energy sources. It aims to reduce reliance on primary energy sources and enhance decentralized energy production. Energy storage is another area that needs to be explored for quickly storing the generated energy. Supercapacitor is a familiar device with a unique quick charging and discharging feature. Encouraging advancements in energy storage and harvesting technologies directly supports the efficient and comprehensive use of sustainable energy. Yet, self-optimization from independent energy harvesting and storage devices is challenging to overcome. It includes instability, insufficient energy output, and reliance on an external power source, preventing their direct application and future development. Coincidentally, integrating energy harvesters and storage devices can address these challenges, which demand their inherent action. This review intends to offer a complete overview of supercapacitor-based integrated energy harvester and storage systems and identify opportunities and directions for future research in this subject. [ABSTRACT FROM AUTHOR]

[Display omitted] • Dual-metal cocatalysts consisting of Pt NCs and In NPs were anchored on CN matrix. • The optimal Pt-In/CN exhibited an impressive photocatalytic H 2 production activity. • Pt NCs and In NPs as traps boosted the separation and migration of photogenerated charges. • Bimetallic cocatalysts regulated optimal adsorption behavior of H* intermediates for fast kinetics. Photocatalytic H 2 production is envisioned as a promising pillar of sustainable energy conversion system to address the energy crisis and environmental issues but still challenging. Herein, a strategy is proposed to design a dual-metal cocatalysts consisting of Pt nanoclusters (Pt NCs) and In nanoparticles (In NPs) anchored on polymeric carbon nitride (Pt-In/CN) for boosting photocatalytic water splitting. As expected, the designed Pt-In/CN photocatalyst exhibits an impressive H 2 production rate of 6.49 mmol·h−1·g−1 with an apparent quantum yield (AQY) of 33.56 % at 400 nm, which is 2.8- and 11.2-fold higher than those of the Pt/CN and In/CN, respectively. Combining experimental characterization with theoretical calculation demonstrates the synergistic mechanisms underpinning the enhanced photocatalytic activity. The Pt NCs and In NPs serve as photogenerated electron and hole trapping sites, respectively, which achieves the spatial separation of charge carriers and induces the polarized surface charge distribution, thus fostering optimal adsorption behavior of intermediates. More importantly, the p-block In NPs modulate the electronic microenvironment of Pt NCs to attenuate the adsorption behavior of H* intermediates for accelerated H 2 evolution kinetics. This work unveils a versatile strategy to regulate the electronic structures of dual-metal sites with synergy by establishing charge transfer mechanism for dual-metal cocatalysts. [ABSTRACT FROM AUTHOR]

The AlCl 3 /ZnCl 2 aqueous solution acts as a benign cellulose solvent, polymerization catalyst for acrylamide monomer, effective ion source for electron transport networks, and dynamic riveting point for hydrogel networks. [Display omitted] 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 AlCl 3 /ZnCl 2 /H 2 O solvent to create cellulose/polyacrylamide-based hydrogel (AZ-Cel/PAM) with expanded hierarchical topologies. The aqueous AlCl 3 /ZnCl 2 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. [ABSTRACT FROM AUTHOR]

Mobilization of in situ fine particles in geothermal reservoirs is a key contributor to permeability damage and clogging of the reservoir rock, leading to a decline in well productivity during enhanced geothermal operations. This phenomenon is a result of disturbance in the mechanical equilibrium of the forces acting on a given fine particle, most significant of which are electrostatic and drag forces. These forces are affected by changes in fluid flow velocities, in situ temperatures, or ionic strength of in situ fluids. Theoretical formulation of migration of fine particles in porous media driven by non-isothermal flow remains challenging, and requires a considerable number of parameters to quantify the characteristics of a given colloidal particle-pore fluid–solid grain system. The identification of all the involved parameters often necessitates costly, intricate, and time-consuming physical experiments. Moreover, implementing the complete form of the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory, commonly adopted to evaluate changes in electrostatic forces, is complicated, computationally demanding, and impractical, particularly when applied to evaluate fines migration at a reservoir scale. This study presents a theoretical framework for accurate and practical prediction of fine particle migration driven by non-isothermal flow in a clay-NaCl-quartz system. The novel contributions of this study are twofold. Firstly, a new numerical model is developed based on the complete DLVO theory, which integrates for the first time the effects of both thermal and hydraulic loads on all underlying parameters including both the static dielectric constant and the refractive index of the pore fluid. Secondly, an innovative simplified DLVO-based model has been introduced, requiring notably fewer parameters compared to existing models, thus offering a practical and efficient solution. The proposed models are utilized to conduct a comprehensive assessment of the fundamental mechanisms involved in fine particle liberation. Findings are key to predict fines-migration-induced permeability damage in geothermal reservoirs to achieve a sustainable design of energy storage/production operations as well as to develop effective strategies to prevent or mitigate the decline in well productivity in time. [ABSTRACT FROM AUTHOR]

With deteriorating air pollution and climate change, generating power with cleaner technologies to meet energy demand of economic development has become a crucial policy consideration globally. Biomass power generation, despite being cleaner than coal power generation, still emits certain air pollutants that can impact ambient air quality. On the other hand, biomass power plants might mitigate air pollution by reducing open-field crop burning. With this counteracting in play, it is unclear which effect is dominant and how biomass power generation affects ambient air quality eventually. We build a unique spatially high-resolution dataset for 20-km-radius circles, considering both regions with biomass power plants and those without, to explore the impacts of biomass power generation on air quality in nearby regions. By applying panel and canonical difference-in-differences models with various model specifications and estimation strategies, we demonstrate that biomass power generation in China significantly reduces ambient annual concentrations of PM2.5, PM10, SO2, and CO. The impacts on NO2 reduction could only be observed in summer, when open-field burnings decreased substantially. The impacts on PM2.5 could be observed in both summer and fall. No seasonal pattern is observed for the reductions in PM10, SO2, and CO concentrations. [ABSTRACT FROM AUTHOR]

The agricultural growth of the nation resulted in the elevated amount of agricultural toxic contaminants in water. It is a promising technique for the degradation of agricultural pollutants. Photocatalysis is termed the utilization of light energy as an inexhaustible and green energy source for degrading organic pollutants through reactive oxygen species generation. The agricultural pollutants mainly comprise pesticides, herbicides, and certain veterinary contaminants. This paper aims to discuss the prevalence of various photocatalytic agents in the degradation process of agricultural pollutants in water. Considering this, the present review has attempted to look back at the existing research based on applying chemical agents as photocatalysts to treat contaminated water systems. Literature that falls within the period from 2018 to 2023 is chosen, and the effects of various photocatalytic agents on agricultural pollutants have been explored. The categorization of the existing literature is highly relevant for future research that aims to recognize the role of photocatalytic agents and their contribution toward the purification of water systems and the eradication of agricultural pollutants. It also highlights the challenges and benefits of incorporating photocatalytic agents for the degradation process of agricultural pollutants. [ABSTRACT FROM AUTHOR]

Examining the game-changing possibilities of explainable machine learning techniques, this study explores the fast-growing area of biochar production prediction. The paper demonstrates how recent advances in sensitivity analysis methodology, optimization of training hyperparameters, and state-of-the-art ensemble techniques have greatly simplified and enhanced the forecasting of biochar output and composition from various biomass sources. The study argues that white-box models, which are more open and comprehensible, are crucial for biochar prediction in light of the increasing suspicion of black-box models. Accurate forecasts are guaranteed by these explainable AI systems, which also give detailed explanations of the mechanisms generating the outcomes. For prediction models to gain confidence and for biochar production processes to enable informed decision-making, there must be an emphasis on interpretability and openness. The paper comprehensively synthesizes the most critical features of biochar prediction by a rigorous assessment of current literature and relies on the authors' own experience. Explainable machine learning techniques encourage ecologically responsible decision-making by improving forecast accuracy and transparency. Biochar is positioned as a crucial participant in solving global concerns connected to soil health and climate change, and this ultimately contributes to the wider aims of environmental sustainability and renewable energy consumption. [ABSTRACT FROM AUTHOR]

Developing an efficient system is essential for energy storage, especially sustainable sources of energy, which have expanded significantly in the last few years. However, the fabrication of effective materials proves an aid to solve such crises of high cost and low specific capacitance. Transition and inner transition metal oxides play a significant role in energy storage as well as energy conversion systems. In this research, a novel material CuO/CeAlO 3 nanocomposite is synthesized by sonication technique for supercapacitor applications. The different physical methods including X-ray diffractometer (XRD), Raman and Scanning Electron Microscopy (SEM) were employed to analyze the phase purity, structure as well as morphology of the prepared electrode. Electrochemical investigations concluded that the CuO/CeAlO 3 nanocomposite exhibited specific capacitance of 1091.98 F/g, high energy density of 56.26 Wh/kg, high power density of 304.55 W/kg at 1 A/g current density as well as high cyclic stability after 5000th cycle with lower charge transfer resistance of 0.09 Ω. The electrochemical characteristics of CuO/CeAlO 3 nanocomposite were improved because of the increased area of surface, large active sites and decreased resistance that resulted from the addition of CeAlO 3 with CuO. This research showed the great potential of CuO/CeAlO 3 nanocomposite along with inexpensive fabrication cost and could be used in next-generation energy storage systems. [ABSTRACT FROM AUTHOR]

The combination of microbial CO 2 reduction process and photocatalysis can meet the economic goal of sustainable carbon neutrality. Solar-energy as driven force can be achieved, by mimicking natural photosynthesis through the interaction between photo-responsive semiconductor nano-materials and electroautotrophic bacteria (EAB). Therefore, we reviewed the engineering strategies developed in recent years for photocatalytic microbial fixation of CO 2 to improve extracellular electron transfer (EET) rate and enhance the conversion efficiency of solar-to-chemical energy, including (1) the application principles of semiconductor nanomaterials in microbial CO 2 reduction systems; (2) photocathode; (3) photoanode; (4) dual photoelectrodes and (5) inorganic-microbe hybrid system; (6) perspectives on future challenges and opportunities for photocatalytic microbial fixation of CO 2 for sustainable energy and chemical production. This review will provide a theoretical basis for the future development of photocatalytic microbial fixation of CO 2 in energy harvesting, CO 2 fixation, and chemical synthesis. [ABSTRACT FROM AUTHOR]

This paper proposes stochastic programming to optimal economic scheduling problems of a sustainable integrated energy system with renewable resources including power, natural gas, and hydrogen carriers. Hydrogen is considered a byproduct of electrical power and natural gas carriers using water electrolysis and steam methane reform process technologies. The main objective is to minimize the operation and emission costs while addressing uncertainties of electric/heating/cooling demands, electricity price, and renewable generation using scenario-based stochastic programming. To achieve a risk-hedging strategy, downside risk constraints are involved to minimize the risky scenarios portfolio. The whole problem is modeled as mixed-integer linear programming in GAMS optimization software. The analysis revealed that the expected operation cost without DRC is $ 577.52 and the expected risk-in-cost value for risky scenarios is $ 470.7. However, a conservative decision for reaching zero risk is costly and increases the expected cost up to $ 2901.1, which is not economically viable. A modest decision-making strategy compromises the cost and risk values where for decreasing the risk-in-cost to $ 288.7 (36.8%), the expected cost increased by to $1010.39 (75.95%). Moreover, the risk-averse decision-maker lowers the power sold to the grid, increases the use of water electrolyzing instead of the SMR process to reduce the environmental charges, and tries to increase flexibility with the help of hydrogen and battery storage. • The operation of a multi-carrier energy system is evaluated by stochastic programming. • The risk of different uncertainties is involved using downside risk constraints. • The risk-neutral and risk-averse strategies are developed by adjusting a risk level. • The hydrogen carrier considered as an intermediate to serve multi-energy demands. • The water electrolyze and steam methane reform technologies produce hydrogen gas. [ABSTRACT FROM AUTHOR]

Hydrogen, as a clean energy carrier, presents a significant step toward sustainable energy solutions but faces challenges in storage due to its low energy density and high volatility. This study addresses the optimization of Type V hydrogen storage tanks by investigating the burst pressure performance of spherical, cylindrical, and toroidal shapes. Using finite element analysis (FEA) and first-order shear deformation theory, we examined how these geometries impact burst pressure outcomes across a range of composite materials and layup configurations. The materials tested included carbon T700/epoxy, Kevlar/epoxy, E-glass fiber/epoxy, and basalt/epoxy. Results demonstrate that the toroidal shape significantly outperforms spherical and cylindrical designs in stress distribution and burst pressure, with basalt/epoxy composites exhibiting superior burst pressure performance (12.7 MPa) compared to Kevlar/epoxy (10.8 MPa), E-glass fiber/epoxy (11.4 MPa), and carbon T700/epoxy (8.9 MPa). Kevlar/epoxy toroidal tanks outperform other materials in weight performance, having a structural performance index of 0.0305 Mpa.m3/kg and hydrogen density per unit mass of 0.0251 kg H 2 /kg. The stacking sequence [-45/45]s optimized stress distribution for the toroidal shape across all materials. The findings highlight that toroidal designs offer significant advantages for high-pressure hydrogen storage, providing efficient stress management and improved safety. This paper underlines the potential of toroidal vessels for enhancing hydrogen storage efficiency and emphasizes the importance of material selection and stacking sequences in achieving optimal burst pressure performance for international organization for standardization (ISO) certification. • Toroidal tanks show superior burst pressure over spherical and cylindrical designs. • The [-45/45]s stacking sequence optimizes stress distribution for toroidal tanks. • Basalt/epoxy composites outperform other materials in burst pressure performance. • Kevlar/epoxy toroidal tank outperforms others in weight performance. • Toroidal tanks offer efficient stress management and enhanced safety for hydrogen storage. [ABSTRACT FROM AUTHOR]

The emergence of sustainability concepts within the energy sector has prompted a heightened interest in exploring alternative avenues to meet global energy demands. The embracement and integration of SDG 7 as a pivotal objective for the future energy landscape have spurred the development of comprehensive frameworks aimed at embedding sustainability principles within the energy sector's core fabric. In this pursuit of sustainable energy solutions, bio-hydrogen has emerged as a promising waste-to-energy concept, serving as a bridge between SDG 6 and SDG 7, thereby addressing both waste management and energy production imperatives. Among the diverse array of methods, biomass fermentation stands out as an effective approach, wherein waste streams derived from industrial and municipal sources can be utilized as feedstock for biohydrogen fermentation. While this approach exemplifies a step towards a circular economy, the treatment of the fermentation broth poses significant challenges, primarily due to the generation of bio-hazardous and toxic effluents. The fermentation broth is replete with microbial species, metabolites, organic compounds, and inorganic residues, rendering direct discharge untenable due to the adverse environmental and ecological ramifications. Consequently, the treatment and management of fermentation effluent have emerged as formidable techno-economic barriers inhibiting the industrial-scale upscaling of biohydrogen production processes, prompting widespread attention within the research community. This review aims to elucidate the various practices employed in post-fermentation broth treatment and management, shedding light on current methodologies, and highlighting areas for future advancement, particularly towards achieving zero liquid discharge from hydrogen fermentation processes. • Scale up of biohydrogen as clean and green energy source hindered by technical, economic and environmental factors. • Post-fermentation broth from biohydrogen production poses ecological ramifications. • Manging the broth while adding value to waste need of the hour. • Pathways for simultaneous effluent management and adding economic value to the waste overviewed. [ABSTRACT FROM AUTHOR]

The development of new efficient bifunctional catalysts for overall water splitting is of great importance to address the escalating global energy demand. Among these catalysts, two-dimensional-material-supported single-atom catalysts (SAC) have attracted widely attention due to their outstanding sensitivity, activity, and efficiency compared to traditional catalysts. Here, we employed density functional theory (DFT) calculations to investigate the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic performance for 12 single-TM-atom-embedded NbS 2 monolayer (TM-NbS 2). The results reveal that Pt/Co–NbS 2 has the ideal HER activity, characterized by Δ G H* values of 0.03 eV. While Pt–NbS 2 represents exceptional OER catalytic performance with an OER overpotential of 0.52 V. Notably, Pt–NbS 2 is a potential HER/OER bifunctional catalyst for overall water splitting because of its extremely low overpotential. Our findings broaden the understanding of two-dimensional NbS 2 and offer valuable insights for the rational design of transition metal-based bifunctional electrocatalysts. [Display omitted] • 12 TM-atom-substituted ML-NbS 2 to realize bifunctional (both HER and OER) catalysis. • Pt/Co-ML-NbS 2 is the best one due to the lowest overpotential of 0.03 eV. • We find Pt–NbS 2 and Ni–NbS 2 can be good candidates as bifunctional SACs to achieve HER/OER for utilization in clean energy production. [ABSTRACT FROM AUTHOR]

Electrocatalytic water splitting is a very important energy conversion technology that utilizes renewable energy sources to produce hydrogen for sustainable energy development. In this work, the catalytic performance of 1T-VS 2 (1T phase of vanadium disulfide) nanoribbons in the hydrogen evolution reaction (HER) was investigated based on first-principles calculations. It was found that 1T-VS 2 nanoribbons have a Gibbs free energy (ΔG H*) of 0.05 eV, demonstrating its excellent HER performance. Moreover, some transition metal substitutions can further improve this performance (e.g. the ΔG H* of the Ti/Fe-1T-VS 2 are as low as −0.02/0.04 eV). The mechanism of the performance enhancement is thoroughly investigated. The improved catalytic performance of HER is mainly promoted by hybridization between the V- d and TM- d- orbitals. The crystal orbital Hamiltonian population (COHP) and integral crystal orbital Hamiltonian habitation (ICOHP) calculations show that the HER properties are closely related to the filling of bonding and antibonding states. The differential charge density indicates that the adsorption of H results in an effective charge transfer at the interface and an increase in the conductivity, leading to an increase in the HER. The HER activity of the TM-1T-VS 2 (TM stands for transition metal) nanoribbons is also related to the proximity of the adsorption site to the edge. Our work suggests that the TM-1T-VS 2 nanoribbons are expected to be low cost and highly efficient catalysts. [Display omitted] • 1T-VS 2 nanoribbons have ΔG H* of 0.05 eV, showing its excellent HER performance. • TM SACs on 1T-VS 2 nanoribbons greatly improve the HER performance. • The ΔG H* of the Ti/Fe-1T-VS 2 are as low as −0.02/0.04 eV. • HER activity is related to the filling of bonding and antibonding states. • Location of TM also affects the activity of TM-1T-VS 2 nanoribbons. [ABSTRACT FROM AUTHOR]

The synthesis and characterization of novel polythiophene (PTh)-based electrocatalysts incorporating NiCo-LDH and NiCo 2 S 4 additives for oxygen evolution reaction (OER) are investigated. NiCo-LDH and NiCo 2 S 4 are synthesized using standard precipitation techniques and characterized using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). PTh-based composite coatings are electrodeposited on steel substrates with varying concentrations of NiCo-LDH and NiCo 2 S 4. The electrochemical performance of the composite coatings is evaluated using linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and stability tests. Results reveal that the incorporation of NiCo-LDH and NiCo 2 S 4 enhances the catalytic activity of PTh-based electrocatalysts for OER, with PTh@NiCo 2 S 4 exhibiting superior performance. The synergistic effects of the additives improve charge transfer kinetics and interfacial conductivity, leading to efficient oxygen generation. The study demonstrates the potential of tailored composite materials for advancing sustainable energy conversion technologies. • Novel PTh-based electrocatalysts incorporating NiCo-LDH and NiCo 2 S 4 enhance OER catalysis. • Synergistic effects improve charge transfer kinetics and interfacial conductivity. • Structural disparities influence catalytic activity, with PTh@NiCo 2 S 4 exhibiting superior performance. • Unexpected findings challenge conventional beliefs on the correlation between C dl and catalytic activity. • Tailored composite materials offer promising avenues for advancing sustainable energy conversion technologies. [ABSTRACT FROM AUTHOR]

The transition to sustainable energy sources is a global imperative in the face of climate change and dwindling fossil fuel reserves. Hydrogen, as a clean and versatile energy carrier, has garnered significant attention as a potential solution. This paper provides a comprehensive overview of various electrolyzer types, their features, advantages, disadvantages, and future expectations in the context of sustainable energy generation. The article begins by outlining the fundamental principles of electrolysis, highlighting its potential to harness surplus renewable energy. Four main types of electrolyzers are discussed: alkaline electrolyzers, proton exchange membrane electrolyzers, anion exchange membrane electrolyzers, and solid oxide electrolyzers. Each type is explored in depth, with a focus on their unique operating principles, efficiency, scalability, and suitability for different applications. The paper further delves into recent advancements in electrolyzer technology, discussing emerging trends, improved catalysts, and innovative system designs aimed at enhancing efficiency and reducing costs. It also explores the role of policy support and research initiatives in accelerating the adoption of electrolysis for sustainable hydrogen production. • Water electrolyzer systems are one of the most promising technologies for green hydrogen production. • This review provides insights into the current state and future potential of water electrolysis technologies. • Challenges, advantages, and future directions of electrolyzer types are discussed. • Green hydrogen plays a crucial role in decarbonization efforts and offers a sustainable solution for future energy needs. [ABSTRACT FROM AUTHOR]

Significant research is currently performed on electrochemical water splitting to solve ecological problems and energy issues. Sustainable and eco-friendly energy systems prefer to generate cost-effective electrocatalyst material with higher stability and excellent electrocatalytic activity to speed up the oxygen evolution reaction (OER) process. The current study followed a hydrothermal approach to develop a barium cerium oxide nanohybrid with g-CN (BaCeO 3 /g-CN) as an electro-catalyst for an efficient OER process in 1.0 M KOH. Physical characteristics analyses confirmed the enhanced activity of the synthesized BaCeO 3 (BCO) and BCO/g-CN nanohybrid materials. The evaluated increased performance may be ascribed to improved morphological characteristics and substantial surface area (212 m2 g−1). The nanocomposite as mentioned above (BCO/g-CN) exhibits significant potential for effective OER in electrochemical assessments due to its abundant active spots and accelerated charge transfer process. Further, the electro-catalytic activity of the composite is improved, as demonstrated by a reduced overpotential (η = 210 mV) with Tafel value (36 mV dec−1) in comparison to pristine BCO (η = 262 mV and 52 mV dec−1) for OER. The material exhibited a reduced charge transfer impedance (R ct = 0.7 Ω), confirmed by EIS analysis. It also demonstrated a substantial ECSA (electrochemical active surface area) of 237.5 cm2 as compared to the pure BCO (137.5 cm2) material. Moreover, electrocatalyst material durability for 30 h was assessed by a chronoamperometric study. Thus, BCO/g-CN exhibits a notable rise in electrochemical properties, suggesting that it is a viable candidate for prospective OER applications. [Display omitted] • BaCeO 3 /g-CN nanomaterial was synthesized by simple hydrothermal technique. • The conductivity of nanohybrid BaCeO 3 was analyzed under 1.0 M KOH for OER. • BaCeO 3 /g-CN material had higher surface area (70.6 m2 g−1) than pure BaCeO 3. • The cyclic stability of BaCeO 3 /g-CN is remarkable after 5000 cycles. [ABSTRACT FROM AUTHOR]

Solar energy storage technology ensures a sustainable and reliable energy supply. Herein, we show that electrons generated in semiconductor nanocrystals (NCs) of CsPbBr3 by visible light excitation can be stored in polyoxometalates (POMs) of W10O32, and extracted as an electric current using a photoelectrochemical cell. [ABSTRACT FROM AUTHOR]