We carry out a comprehensive numerical investigation to evaluate the influence of various hole transport layers (HTLs) on the performance of FTO/TiO2/Mg2Mn3O8/HTL/Ag solar cells. Five HTLs, PEDOT:PSS, P3HT, Spiro-OMeTAD, Cu2O, and MoO3, were examined through J–V characteristics, impedance spectroscopy, conductance–frequency analysis, C–V profiling, and Mott–Schottky evaluation. The results reveal that the choice of HTL strongly governs the built-in potential, interfacial recombination, and carrier extraction efficiency. P3HT produced the lowest performance due to reduced Vbi (0.52 V) and limited conductance, while Spiro-OMeTAD showed intermediate behavior with improved transport and a moderate Vbi of 0.67 V. In contrast, Cu2O and MoO3 delivered the highest device efficiencies, achieving PCE values of 27.51 and 27.25
Renewable energy technologies are crucial for achieving global sustainability. Among green energy solutions, power generation through hydrovoltaic devices stands out as a particularly promising option. One of the promising materials for hydrovoltaic power generation is layered double hydroxide, a class of lamellar compounds in which interactions occur between water and the surface of the active material. In this work, a sustainable hydrovoltaic device is fabricated by decorating a synthesized NiCo LDH onto a natural coconut fibre substrate, providing an eco-friendly alternative to conventional systems and aligning with the Sustainable Development Goals. NiCo LDH is an ideal hydrovoltaic material due to its layered hydrophilic structure, tunable surface charge and efficient ion transport pathways. Intercalating polyvinyl pyrrolidone (PVP) into the NiCo LDH structure enhances its hydrophilicity and ionic conductivity, leading to improved efficiency in water-driven electricity generation. The fabricated devices, comprising NiCo LDH-decorated coconut fibre and PVP/NiCo LDH-decorated coconut fibre, were subjected to biased, sweep and loop measurements. The optimised device delivers an open-circuit voltage of 255 mV, a short-circuit current of 50 μA, and a maximum power density of 123.07 μW g⁻1. Additional data involving solvent variation and solar illumination were collected to elucidate the key operating parameters. This paper explores the synthesis, mechanism and potential of polymer-intercalated NiCo LDH for enhancing hydrovoltaic power generation, aimed at promoting a sustainable energy future.
Abstract This study investigates the double-perovskite hydride K 2 MnTlH 6 as a promising and previously unexplored absorber for perovskite solar cells (PSCs) using the SCAPS-1D simulator. Key parameters including the electron-transport layer (WS 2 ), hole-transport layer (CBTS), absorber thickness, defect density, and doping concentration are systematically optimized. Results show that WS₂ and CBTS provide favorable band alignment and efficient carrier extraction, enhancing the open-circuit voltage (V OC ), short-circuit current density (J SC ), fill factor (FF), and overall power conversion efficiency (PCE). Interfacial defect densities at the WS 2 /K 2 MnTlH 6 and K 2 MnTlH 6 /CBTS interfaces are analyzed to elucidate recombination and charge-transfer behavior. Additional evaluations of series resistance, shunt resistance, and operating temperature assess device performance under realistic conditions. The optimized configuration achieves a V OC of 1.13 V, J SC of 34.74 mA/cm², FF of 83.56%, and a PCE of 29.41%, confirming K 2 MnTlH 6 as a strong candidate for next-generation, environmentally friendly PSCs.
In this study, proton exchange membranes (PEMs) based on chitosan (CS), sulfonated polystyrene (SPS), and pristine or modified nanosilica were fabricated for direct methanol fuel cell (DMFC) applications. Membranes containing different SPS contents were prepared, and polystyrene was sulfonated to an optimal degree of sulfonation determined by evaluating its hydrolytic stability. Proton conductivity and methanol permeability were measured to determine the membrane selectivity parameter (defined as the ratio of proton conductivity to methanol permeability), which was used to optimize the CS/SPS blend composition to achieve an optimal balance between proton conductivity and methanol crossover resistance. Among the prepared membranes, the membrane containing 40 wt
Solid oxide fuel cells (SOFCs) offer high energy conversion efficiency alongside excellent fuel flexibility. However, their complex underlying electrochemical processes require successful parameter identification so that modeling and control can be achieved. Traditional optimization algorithms on the other hand often face limitations in this problem, such as premature convergence to suboptimal solutions, or an inability to explore the entire solution space. In this manuscript a new metaheuristic based on vulture foraging is derived i.e., Griffon Vulture Optimization Algorithm (GVOA). It is superior in terms of accuracy, stability and computational speed in case of complicated optimization, such as SOFC parameter identification. GVOA’s guided convergence and controlled diversity provide a theoretically sound and practical solution. Because of its efficiency, it can be used for real-time modeling and adaptive control. The GVOA algorithm was successfully used to estimate seven nonlinear model parameters of a simplified SOFC model in ten different operating conditions (varying temperature and pressure), based on simulated V-I data. In comparison with 9 well-known metaheuristic algorithms, such as BKA, AO, LSO, and PEOA, GVOA always gave the lowest minimum mean squared error (MSE) results under any temperature and pressure conditions. Furthermore, it occupied the highest rank in the Friedman test in all situations and had the quickest convergence behaviour. These results validate GVOA’s superior accuracy, stability and speed with respect to the challenging task of identification of SOFC parameters. Theoretically, this is evidence in support of the efficacy of its combination of guided convergence and controlled diversity, and, practically, is a reliable method for modeling and adaptive control of fuel cell systems. Upcoming research will be spread to investigational validation and application to other electrochemical systems.
Magnesium-based alloys are promising hydrogen storage materials due to their high capacity but suffer from slow hydrogenation kinetics and high operating temperatures. While high-pressure torsion (HPT) enhances kinetics through microstructural refinement, and nickel addition provides catalytic effects, their combined influence on hydrogen storage performance remains insufficiently characterized. This work investigates Mg-Ni composites with variable Ni content (2–16 at
This review provides a critical and forward-looking analysis of recent advancements in magnesium-based electrode materials for supercapacitors, a class of materials distinguished by their unique combination of high theoretical capacity, divalent charge carrier (Mg2+), and sustainability profile. Moving beyond a simple summary, the work systematically deconstructs the electrochemical performance and charge storage mechanisms of key material families, including oxides (e.g., MgCo2O4, MgO), hydroxides, sulfides, and hybrid composites by linking specific structural modifications (nanostructuring, doping, composite formation) to their resultant impact on conductivity, stability, and capacitance. A central and unique contribution of this review is its structured critical evaluation, which clearly delineates the persistent challenges of poor intrinsic conductivity and ion diffusion kinetics, and their direct consequences on device-level performance. Furthermore, the review merges current literature into actionable, strategic research pathways. It prioritizes advanced material engineering, such as the design of conductive 3D heterostructures and defect-controlled doping, to chart a clear course for overcoming existing limitations. Ultimately, this work positions magnesium-based electrodes not merely as alternatives but as a viable and sustainable platform for next-generation energy storage, provided these focused research directions are pursued.
Abstract Agricultural biomass offers a sustainable and cost-effective precursor for synthesizing activated carbon (AC) electrodes in energy storage systems, addressing both the global energy crisis and the environmental challenges of fossil-based materials. Biomass-derived carbons have gained increasing attention for supercapacitor applications due to their natural abundance, tunable porosity, and excellent electrochemical properties. This review critically examines recent progress in processing routes, activation strategies, and structure-property relationships of AC derived from agricultural wastes. Emphasis is placed on emerging approaches such as heteroatom doping, template-assisted activation, and composite design that enhance energy density and cycling stability. The novelty of this work lies in its integrated analysis of synthesis–performance correlations and the identification of future pathways toward scalable, green production of high-performance, biomass-derived AC electrodes for next-generation supercapacitors.
This study investigates the double-perovskite hydride K2MnTlH6 as a promising and previously unexplored absorber for perovskite solar cells (PSCs) using the SCAPS-1D simulator. Key parameters including the electron-transport layer (WS2), hole-transport layer (CBTS), absorber thickness, defect density, and doping concentration are systematically optimized. Results show that WS₂ and CBTS provide favorable band alignment and efficient carrier extraction, enhancing the open-circuit voltage (VOC), short-circuit current density (JSC), fill factor (FF), and overall power conversion efficiency (PCE). Interfacial defect densities at the WS2/K2MnTlH6 and K2MnTlH6/CBTS interfaces are analyzed to elucidate recombination and charge-transfer behavior. Additional evaluations of series resistance, shunt resistance, and operating temperature assess device performance under realistic conditions. The optimized configuration achieves a VOC of 1.13 V, JSC of 34.74 mA/cm², FF of 83.56
Abstract The search for efficient, lead-free perovskite solar cells motivates the exploration of stable chalcogenide absorbers like BaSnS₃. To address the need for systematic interface engineering in these devices, this SCAPS-1D simulation study investigates the integration of a single-walled carbon nanotube (SWCNT) interlayer. We first optimize an FTO/TiO₂/BaSnS₃/P3HT/Ag baseline cell, achieving a power conversion efficiency (PCE) of 26.05%. By introducing and optimizing a SWCNT layer, the PCE is boosted to 29.15%—an absolute gain of 3.10% points. Our analysis deconvolutes this enhancement, attributing it to improved charge extraction (increased fill factor to 86.19%), a higher built-in potential, and extended near-infrared absorption. A sensitivity analysis confirms the robustness of this gain even with more realistic SWCNT parameters. The study provides clear design rules and quantifies the theoretical performance ceiling for SWCNT-engineered interfaces, offering a valuable guide for experimental development of high-efficiency, lead-free chalcogenide perovskite photovoltaics.
Abstract During the last few years, new materials for multifunctional optoelectronic applications have been developed with the aim of generating eco-friendly and renewable solar energy, therefore reducing the cost of electricity production and improving luminous efficiency through a simple manufacturing process. In the present work, the nano powder Ba 0.5 Sr 0.5 Fe 12 O 19 hexaferrite sample was successfully synthetized via the sol gel auto-combustion process and was characterised by room temperature X-ray diffraction (XRD) and UV–Visible-NIR spectroscopy. The structural study proved that the studied sample crystallises according to the hexagonal system with the (P6 3 /mmc) space group. The spectral behaviour of absorbance proves that the studied sample exhibits a broad absorption in the UV–Visible light region as well as a tunable direct optical gap of 1.81 eV. Further analysis of the extinction coefficient, refractive index, dispersion parameters, optical dielectric constant, nonlinear optical parameters as well as optical conductivity were highlighted and investigated in order to undertake a deeper and better insight into the optoelectronic behaviour of hexaferrite compound. The obtained results place emphasis on a powerful luminous efficiency as well as the suitability of the studied Ba 0.5 Sr 0.5 Fe 12 O 19 hexaferrite compound for the manufacture of optoelectronic devices.
Abstract Machine learning (ML) has become a pervasive tool in clean-energy materials research, accelerating virtual screening, inverse design, catalyst discovery, process optimisation, and autonomous experimentation across a range of domains. This review offers a systematic and deliberately critical assessment of what that acceleration has and has not yet delivered. Across twelve application domains spanning CO $$_2$$ reduction, hydrogen evolution, nitrogen reduction, ML interatomic potentials, generative inverse design, battery lifetime prediction, sustainable manufacturing, critical-material recycling, and operando characterisation, we introduce the Materials–ML Maturity Matrix (M4) to rate each domain on four dimensions: data reliability, model robustness, experimental and industrial readiness, and generalisation stability. No domain currently achieves high ratings on all four dimensions simultaneously. Four findings emerge from this analysis. First, ML performance outside training distributions is consistently and substantially lower than benchmark results indicate. Second, experimental validation rates for ML-generated candidates remain below 5–10% in inverse-design workflows, and adsorption-energy predictions in catalysis routinely diverge from experiment by more than 0.3 eV. Third, cross-facility reproducibility of autonomous laboratory results has not been established at scale. Fourth, no ML-designed material has yet outperformed the state of the art across the combined metrics of activity, selectivity, stability, and cost in any application area reviewed. Battery lifetime prediction and manufacturing optimisation represent genuinely mature and industrially relevant applications. NRR catalysis and fully autonomous discovery remain at an early, largely conceptual stage. The most binding constraints across domains are infrastructural—data quality, benchmark integrity, and uncertainty quantification—rather than architectural. A five-year priority roadmap grounded in the M4 analysis identifies the interventions most likely to convert ML’s demonstrated acceleration into genuine transformation of clean-energy materials development.
Abstract Bipolar plates (BPs) are crucial components of proton exchange membrane fuel cells (PEMFCs), which provide electrical conductivity, structural integrity, and play a critical role for gas distribution and water management. However, the preparation of low-cost BPs with mutually enhanced electrical conductivity, mechanical strength, and electrochemical durability remains challenging. The present work highlights the utilization of locally sourced, highly graphitized and pure flake shaped natural graphite as a sustainable filler for the development of BPs on a commercial scale, with the required set of characteristics. It functions as an effective natural conductive filler compared to expensive and synthetically produced carbon-based fillers used in literature, involving complex and overdependence on energy-intensive routes. In this study, composites with different natural graphite particle sizes and recyclable polyphenylene sulfide (PPS) have been prepared via ball milling and compression molding process. Comparatively, from twelve different compositions, the composite with a combination of 10 wt% fine graphite, 60 wt% jumbo graphite and 30 wt% PPS demonstrates a synergistic enhancement of electrical/thermal conductivity, thermal stability, and compressive strength. The prepared composite demonstrates a higher degree of crystallinity, high gas (N 2 ) impermeability, and the lowest thermal expansion. The hybrid particle size formulation has the potential to develop natural graphite-based composite BPs with simultaneously improved multifunctional properties, above DOE. This study provides valuable insights to develop natural graphite-based composite BPs through an industrially viable processing approach, for future PEM fuel cell applications.
Abstract Microbial electrolysis cells (MECs) represent a promising strategy for simultaneously treating wastewater, generating green hydrogen, and producing various biobased products, while minimizing environmental impact in alignment with the Sustainable Development Goals (SDGs). These systems have been extensively integrated with bioelectrochemical processes and renewable energy sources, such as solar and wind power, offering a viable pathway for sustainable development. This review provides a comprehensive summary and analysis of MEC's technology, tracing its evolution from its first discovery in 2004 to the present day. The data analyzed were collected from approximately 2000 papers published since 2004, with a particular focus on studies related to the production of green hydrogen, methane, and high-value-added products. Additionally, the review addresses the various challenges associated with MECs, highlighting innovations in design, operational strategies, and anticipated integration with other renewable energy systems. In conclusion, this work outlines a roadmap for future advancements, providing insights into the potential of MECs for hydrogen production, renewable biochemicals, and environmental applications. This framework aims to facilitate the transition from laboratory-scale experiments to industrial-scale implementation.
The development of efficient and affordable technologies for green hydrogen production can significantly help the transition to sustainable energy systems. Among them, anion-exchange membrane water electrolysis (AEMWE) can offer an appealing balance between performance and cost. This requires simple methods for the large-scale synthesis of efficient and low-cost electrocatalysts. In this paper, precious metal-free high-entropy oxides synthesized by the sol–gel method and calcination at different temperatures (400 − 800 °C) are utilized to fabricate the anode of a zero-gap AEMWE full cell, while for the fabrication of the cathode they are first reduced in a H2/Ar atmosphere. The effect of calcination temperature on the cell electrochemical performance, as resulting from the physicochemical properties of the obtained electrode materials, is studied. The electrode pair obtained from the oxide calcined at 600°C allows achieving a current density of 1.33 A cm−2 at a potential of 1.93 V at 50 °C in 1M KOH electrolyte. Besides, it is capable of operating at current densities reaching even 1.0 A cm−2 for 1100 h at a cell potential never exceeding 2.1 V. Overall, the study provides insights into the temperature-driven evolution of multicomponent oxide catalyst properties and its impact on AEMWE performance, contributing to the rational design of efficient and scalable materials for practical applications in sustainable hydrogen generation.
CuO/Cu2O nanostructures were developed on copper substrates through an anodization process in a sodium hydroxide solution, with durations ranging from 0 to 900 s. This study examines how anodization improved the surface activity of the material, which was further enhanced by a two-hour (N2) plasma treatment. The influence of anodization time on the final layers’ structural, morphological and electrochemical properties was investigated. A cubic phase of CuO/Cu2O films was observed from X-ray diffraction (XRD) measurement. Surface roughness and nanostructure density were increased when anodization time was increased, this was confirmed by scanning electron microscopy (SEM). Further electrochemical performance was evaluated by cyclic voltammetry (CV), Galvanostatic Charge-Discharge (GCD) and electrochemical Impedance spectroscopy (EIS). With an areal capacitance of 1250 mF.cm− 2, the sample that was anodized for 600 s and treated with (N2) plasma (Cu-600s-N2) showed the best supercapacitive behavior out of all the samples that were tested. The contributions of diffusion-controlled and capacitive mechanisms to the total amount of charge storage were examined using Dunn’s method. After plasma treatment, EIS measurements also revealed improved electronic conductivity and a sharp rise in electron lifetime from 64 ms to 1592 ms. These findings highlight the metal oxide nanostructures treated with (N2) plasma’s great potential for cutting-edge energy storage applications. The graphical abstract depicts the synthesis of CuO/Cu2O nanostructures through anodization followed by (N2) plasma treatment, highlighting the enhancement in surface morphology and supercapacitive performance, especially for the Cu-600s-N2 sample.
Innovative research into thermal energy retention materials that improve interior thermal efficiency and lower overall energy consumption is prompted by the growing need for energy-efficient buildings. Phase change materials are known for their enormous latent heat storage capacity; however, issues with low thermal conductivity, leakage, and structural stability following repeated thermal cycling limit their practical application. This review work investigated the creation of hybrid biochar-metal foam PCM composites in order to overcome these problems. By adding graphene, rapid heat absorption and release rates are obtained, which considerably enhance thermal conductivity. Biochar, which is produced by pyrolyzing agricultural waste, offers a lightweight, extremely porous, economical, and environmentally acceptable matrix that reduces PCM leakage and promotes capillary-driven form stability. Benefits of metal foam include homogeneous heat distribution, good mechanical resistance, and structural strengthening. PCM is injected into hybrid scaffolds using the vacuum impregnation process to create form-stable composites that improve thermal transfer and minimize leakage. The findings demonstrate the use of composites in thermal-regulating wall panels, roofing systems, and passive energy-saving envelopes. For the future generation of high-performing, energy-efficient buildings, this PCM composite hybrid graphene-biochar-metal foam offers sustainable TES materials.
Abstract The desire for clean, affordable, and efficient energy technologies that can harvest light to generate electricity has led to recent developments in new-generation solar cells. Among them, dye-sensitized solar cells (DSSCs) have numerous merits, including low impact on the environment, facile fabrication procedures, and the associated low cost of raw materials. However, the power conversion efficiency (PCE) of DSSCs is limited by poor electron injection and high charge carrier recombination in conventional photoanode materials. This, in turn, has prompted significant research efforts to find alternative photoanode materials. In this study, we report a novel perovskite-based photoanode material (Sr0.7Sm0.3BO2.89) optimised by varying the B-site using Fe or Co. To achieve this, Sr0.7Sm0.3FeO2.89 (SSF) and Sr0.7Sm0.3CoO2.89 (SSC) perovskites were synthesised using the ball milling method, calcined at 600 °C, and characterised using various techniques. Varying the B-site using Fe or Co significantly influenced the structure and morphology of Sr0.7Sm0.3BO2.89. Both perovskites revealed the formation of irregularly shaped nanoparticles with cubic and tetragonal lattices for SSF and SSC, respectively. SSF, with relatively smaller particle sizes, larger pore volumes, and better crystallinity, exhibited a relatively larger surface area (52.6 m2 g−1), lower energy band gap (2.4 eV), and higher electrical conductivity (4.98 S cm−1) than SSC. This led to the fabrication of SSF photoanode-based DSSCs with an enhanced PCE of 6.24%, outperforming SSC-based devices by ~ 109%. Therefore, this study demonstrates that varying the B-site cations can significantly improve the physicochemical properties of perovskites for use as photoanodes in future DSSCs.
Abstract Alloy coatings based on nickel and phosphorus (NiP) have shown encouraging electrocatalytic activity and stability for the hydrogen evolution reaction (HER) in alkaline conditions. The NiP electrocatalyst offers several advantages over other HER catalysts, including its high activity, stability, abundance, and affordability. The purpose of this study is to determine whether concentration differences of the NH4Cl additive during electrodeposition affect the physical, chemical, and electrochemical properties of the Ni-P alloy deposits. For this purpose, three distinct Ni-P coatings (NP02, NP1, and NP3) are synthesized by electrodeposition using three different concentrations of ammonium chloride (0.2 M, 1 M, and 3 M) in an electrochemical bath also comprising nickel sulfate and sodium hypophosphite. Utilizing powder XRD, AFM, XANES, EXAFS, and SEM-EDX techniques, the synthesized Ni-P coating’s crystal structure, texture, local structure, composition and morphology are analysed. As we moved from NP02 to NP3, the surface texture smoothened, particle size distribution improved, an orderly rise in P-content was observed, the co-ordination number of Ni for the Ni-P bond progressively escalated, and all these led to a gradual increase in their electrocatalytic activity for HER in alkaline media, with NP3 exhibiting the minimum charge transfer resistance and Tafel slope of 53.9 mV dec− 1. Electrodeposition studies using in-situ UV-visible spectroscopic methods show significant variations in the deposition mechanism when the NH4Cl content is altered. Therefore, by adjusting only the additive content in the electrodeposition bath during the synthesis of Ni-P alloy coatings, their P-content, topography, morphology, and local structure can be suitably regulated, consequently favorably tailoring their electrocatalytic activities for HER.
Abstract Efficient solar-to-hydrogen conversion remains challenging due to the limited visible-light activity and rapid charge recombination in conventional photocatalysts. Here, we report a plasmon-enhanced nitrogen-doped niobium pentoxide (N–Nb₂O₅) photocatalyst decorated with gold nanoparticles (Au@N–Nb₂O₅) for high-performance solar-driven photocatalytic hydrogen generation. N–Nb₂O₅ was synthesized via a simple wet-chemical route and calcined at 500 °C, forming crystalline orthorhombic nanoplates with XRD-derived crystallite sizes of 50–55 nm and lateral dimensions of ~ 150 nm (FE-SEM). Gold nanoparticles were subsequently deposited via photodeposition, extending visible-light absorption and narrowing the band gap to 2.3–2.5 eV (UV–DRS). XPS analysis confirmed successful nitrogen incorporation and surface metallization. Photoluminescence studies revealed efficient charge separation and concentration-dependent suppression of radiative recombination. The optimised Au@N–Nb₂O₅ (2 wt% Au) achieved a hydrogen evolution rate of 2168 µmol h⁻1 g⁻1 under natural sunlight, nearly fourfold higher than pristine Nb₂O₅ and N–Nb₂O₅. The ordered nanoplate morphology facilitates charge transport, complementing the interfacial effects of Au, providing a scalable strategy for designing high-performance Nb₂O₅-based photocatalysts for sustainable solar water splitting.
