Hydrogen storage remains one of the foremost challenges in the transition to a clean energy economy. While extensive research has focused on metal hydrides, carbon materials, and complex sorbents, biomass-derived silica materials with high purity (90 wt.%), large surface areas (297-895 m2.g-1), and mesopores (3-60 nm) show strong potential for hydrogen storage but remain largely unexplored. This review highlights the synthesis, structural properties, and hydrogen storage potential of biomass-derived functional silica materials, with a particular focus on rice husk (RH) and bamboo as a sustainable and abundant precursor. Two principal silicon extraction strategies, combustion and alkali treatment, are discussed, emphasizing their influence on silica purity, morphology, and amorphous structure retention. Thermochemical processes, including acid leaching and controlled calcination, are shown to be essential for removing impurities and tailoring textural properties such as surface area, pore volume, and pore architecture. RH-derived silica supports exhibit outstanding effectiveness in dispersing transition metals like Ni and Fe, which in turn significantly improve hydrogen sorption kinetics, catalytic efficiency, and the long-term stability of the material. Additionally, the review explores how various synthesis pathways are expected to influence the performance of resulting materials in hydrogen storage systems, noting how structural collapse during reprecipitation or thermal treatment can negate surface advantages if not properly managed. The combined advantages of sustainability, tunable structural properties, and seamless compatibility with existing hydrogen storage strategies position biomass-derived silica as a highly promising next-generation platform for advanced hydrogen storage applications. Copyright © 2026 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

In this study, UiO-66-NH2, known for its excellent thermal stability, was incorporated into MgH2 for the first time, demonstrating strong catalytic activity in enhancing the hydrogen storage performance of MgH2. The effects of varying UiO-66-NH2 loadings (5, 10, 15, and 20 wt%) on the hydrogen storage behavior of MgH2 were systematically examined using a ball milling process. The introduction of UiO-66-NH2 significantly lowered the onset desorption temperature from 350 degrees C (for milled MgH2) to 280 degrees C. The composite exhibited markedly improved kinetics, achieving rapid hydrogen absorption of approximately 6.2 wt% within 2 min at 250 degrees C under 33.0 atm H2 pressure, and desorption of about 5.9 wt% within 2 min. The apparent activation energy for dehydrogenation decreased to 89.17 f 3.2 kJ/mol H2, compared to 132 f 8.7 kJ/mol H2 for pure MgH2. The MgH2/UiO-66-NH2 composite maintained excellent cyclic stability over 20 cycles, with only a minor capacity loss of about 0.002 wt%. Comprehensive characterization using XRD, TEM, and SEM confirmed the structural and morphological changes, and a plausible catalytic mechanism of UiO-66-NH2 on MgH2 was proposed based on these findings.

Hydrogen storage remains a pivotal bottleneck in achieving a sustainable hydrogen economy, where efficiency and stability are key challenges. Traditional solid-state hydrogen storage materials, metal hydrides, porous frameworks, and complex chemical carriers are limited by slow kinetics and high desorption temperatures. Recent research has unveiled the transformative potential of interface-engineered nanomaterials, where atomic-scale interfacial interactions govern hydrogen adsorption and transport. This review critically examines the emerging paradigm of interface-driven hydrogen storage, emphasising how structural, electronic, and catalytic synergies can revolutionise hydrogen uptake and release. This review pioneers a comprehensive framework linking interface science with hydrogen storage, emphasising dual functionality, a conceptual shift from capacity-focused studies to multi-functional, sustainable design principles. The fundamental mechanisms underlying interfacial hydrogen interactions, highlighting charge redistribution, defect, and heterojunction as key parameters influencing storage behaviour, are elucidated. The review categorises advances in multi-functional nanostructures, including metal–support interfaces, core–shell and yolk–shell hybrids combining hydrides with conductive supports. A comparative analysis of interface-engineering strategies, including doping, nano-confinement, heteroatom modulation, and defect control, reveals how precise material tailoring can simultaneously enhance kinetics, capacity, and cycling stability. The review concludes by identifying key challenges such as scalability, interfacial degradation, and thermodynamic balancing, and proposes future directions to accelerate discovery. Hence, this work redefines solid-state hydrogen storage through the lens of interface science, establishing a design roadmap for multi-functional, sustainable nanomaterials that can bridge the gap between laboratory and real-world hydrogen systems.

This work demonstrates a breakthrough in polymer-assisted interfacial photocatalyst design, revealing that polyethylene glycol (PEG) can function as an active interfacial regulator that simultaneously controls CuO, graphene-semiconductor electronic coupling, and catalyst durability in methylene blue degradation. This study hypothesises that this overlooked interdisciplinary coupling between polymer chemistry and photocatalytic engineering is central to achieving high activity under UV-light while maintaining economic feasibility. PEG-functionalised CuO/graphene composites exhibit uniform in-situ CuO confinement, suppressed charge recombination, and enhanced reactive oxygen species generation, achieving 96.38% methylene blue degradation within 90 min. Importantly, the catalyst retains performance over six reuse cycles with < 15% loss, translating into reduced operational costs compared to single-use photocatalysts. Further, the use of earth-abundant CuO, low-cost polymers, and UV-light positions this system as a scalable alternative to noble-metal-based technologies, with potential cost savings of 30-50% in catalyst-related expenditures for wastewater treatment facilities. Future research should focus on reactor-scale immobilisation, long-term stability, and life-cycle cost assessment, while key challenges remain in catalyst recovery under real wastewater remediation. Unlike other treatments that transfer pollutants, the PEG-functionalised CuO/graphene enables true dye mineralisation under mild conditions. Its reliance on earth-abundant materials rather than noble metals offers a cost-effective alternative for sustainable wastewater treatment. This study establishes polymer-semiconductor-carbon synergy as a practical and economically meaningful direction for next-generation wastewater photocatalysis.

This study presents the application of response surface methodology (RSM) to optimize the removal of methylene blue (MB) using a fibrous nano-silica (KCC-1) photocatalyst derived from waste palm oil fuel ash (POFA) and doped with iron (Fe) nanoparticles. The Fe/KCC-1 composite was synthesized via ultrasonic-assisted impregnation, and its physicochemical properties were characterized using Fourier-transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and X-ray diffraction (XRD). The photocatalyst's efficiency in degrading MB was systematically evaluated using a central composite design (CCD), considering catalyst dosage, pH, and initial concentration as key variables. The CCD generated 20 experimental runs to model the interaction between the variables. The statistical analysis confirmed the robustness of the quadratic model, with a high degree of predictability as indicated by R-2 (0.9457), adjusted R-2 (0.9139), and predicted R-2 (0.8545) values. The model's significance was further supported by analysis of variance results, showing a p-value <0.0001. Among the studied parameters, pH emerged as the most influential factor, as it governs the surface charge of Fe/KCC-1 and the ionization behavior of MB, both of which critically affect adsorption and reactive oxygen species generation. Under optimum conditions (pH 9.0, 10 mg/L MB concentration, and 3.0 g/L catalyst dosage), a maximum degradation efficiency of 89.90% was achieved. Scavenging tests further reveal that center dot OH radicals are the predominant species responsible for MB removal. Additionally, the reusability study demonstrated that Fe/KCC-1 retained substantial activity over five successive cycles, indicating its potential as a stable and reusable photocatalyst for wastewater treatment applications.

This study explores the optimization of methylene blue (MB) photodegradation using a copper-doped fibrous nano-silica (Cu/FNS) photocatalyst synthesized from palm oil fuel ash (POFA), an agricultural waste material. The Cu/FNS composite was prepared through an ultrasonic-assisted impregnation method, with its morphological and surface characteristics analyzed via scanning electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) techniques. To optimize degradation performance, a central composite design (CCD) under response surface methodology (RSM) was employed, evaluating the influence of three main variables, namely catalyst dosage, pH, and initial MB concentration. The CCD framework designed 20 experimental trials, enabling the creation of a predictive model for photocatalytic efficiency. Statistical validation showed the model's strong fit and reliability, supported by high coefficients of determination (R-2 = 0.9995, adjusted R-2 = 0.9990, and predicted R-2 = 0.9959) and a highly significant p-value (< 0.0001). Among the examined factors, pH was identified as the most critical, significantly impacting the electrostatic interactions between the catalyst surface and dye molecules, as well as the formation of reactive oxygen species. Optimal degradation conditions were determined to be pH 8.0, MB concentration of 30 mg/L, and catalyst loading of 5.0 g/L, resulting in a maximum removal efficiency of 92.83%. Furthermore, the photocatalyst demonstrated consistent reusability, maintaining notable activity across five cycles, thus highlighting its potential for practical and sustainable wastewater treatment applications.

A waste-to-wealth strategy is reported for the fabrication of a copper-functionalized fibrous nanosilica (Cu/KCC-1) photocatalyst derived from palm oil fuel ash (POFA), an abundant silica-rich agricultural residue. The Cu/KCC-1 nanocomposite retains the characteristic dendritic fibrous architecture and high surface area of KCC-1, while incorporating catalytically active Cu species within the amorphous silica framework, as confirmed by FESEM, XRD, BET, FTIR, and UV-Vis DRS analyses. The resulting catalyst exhibits outstanding photocatalytic activity toward methylene blue degradation, achieving 94.30% efficiency under UV irradiation at pH 8 with a catalyst dosage of 3 g/L and an initial dye concentration of 10 mg/L. Reaction temperature strongly influenced performance, with optimal degradation at 50 degrees C, beyond which charge-carrier recombination and partial deactivation limited the catalytic efficiency. The superior activity is attributed to enhanced light absorption, increased density of accessible active sites, and improved charge separation induced by Cu incorporation within the fibrous silica matrix. Alkaline conditions further promoted degradation by facilitating reactive oxygen species generation. A mechanism involving surface adsorption followed by center dot OH- and O2 center dot- driven oxidative mineralization is proposed. This study demonstrates the viability of POFA-derived Cu/KCC-1 as a high-performance, low-cost, and sustainable photocatalyst for advanced wastewater remediation.

This study explored an all-inclusive overview of research based on carbon materials for application in CO 2 capture and conversion (CCC) within the past 18 years (2006–2024). The study covered and analyzed 1680 research articles on carbon materials for CCC. Various aspects, such as publication countries, affiliations of the authors, high-impact journals, different areas of research, and key issues attracting discussions in the field, were examined. The results of the study reveal a significant rise in the interest in carbon-based materials for CCC. The top 10 countries with the highest number of publications were led by China with 902 publications. On international collaboration, which defines the total link strength (TLS), China, the United States, and South Korea rank first, second, and third, respectively. The Chemical Engineering Journal excels with a substantial publication volume of 76 articles. The study also discovered that the traditional activated carbon was advanced to a material like graphene and carbon nanotubes (CNTs). This advancement emphasizes the rising concern in addressing CO 2 management challenges. However, substantial challenges persist, including attaining the optimum performance and scalability while integrating CO 2 capture with conversion processes. Thus, there is a crucial need to enhance affordable pre-treatment processes, improve stability, and address the impact of contaminants. Future research should focus on advancing study quality and quantity, strengthening TLS, and encouraging interdisciplinary approaches.

Lead (Pb) is one of the most hazardous heavy metals found in wastewater. Adsorption in a continuous fixed-bed column is used for treating large volumes of wastewater, and the efficiency of this process can be monitored using the breakthrough curve. In this study, fibrous nanosilica (KCC-1) from rice husk ash was employed as an adsorbent and modified using granular sand to prevent it from being difficult to separate from the Pb. The study fabricates a continuous fixed-bed adsorption column loaded with modified-sand KCC-1 to examine the impact of flow rate (10-40 mL min-1), bed height (3-12 cm), and concentrations (50-200 mg L-1) on Pb2+ adsorption. The experiment operated for 5 h, with samples taken every 30 min and analyzed using a UV-Vis spectrophotometer. The results showed that the highest percentage of Pb2+ removal arose at a flow rate of 10 mL min-1, with an adsorption capacity, q, of 29.49 mg g-1, a residence time of 5.0 min, and a removal efficiency of 94.50%. In addition, the adsorption breakthrough was obtained by the Thomas, Adam-Bohart, and Yoon-Nelson models. Based on the adsorption efficiency findings using sand-modified KCC-1, all three models are suitable for describing the adsorption process.

ABSTRACTThis study investigates global research trends on the catalytic performance of metal‐based catalysts for enhanced hydrogen production over the past 89 years (1935–2024) through a comprehensive bibliometric analysis. The research addresses the evolution of metal‐based catalysts in hydrogen production and highlights the most prominent contributors and driving trends. The study analyzed 32,987 peer‐reviewed studies identified through Scopus database. The search was conducted from September 1, 1935, to July 20, 2024, utilizing keywords such as “(TITLE‐ABS‐KEY ((“Ru” OR “Ni” OR “Fe” OR “Co” OR “Mo” OR “Pt” OR “Pd” OR “Cr” OR “metal catalysts*”) AND (“hydrogen production*” OR “H2 production*” OR “hydrogen generation*” OR “H2 generation*”))).” The analysis covered various aspects, such as countries, authors’ affiliations, prominent journals, research areas, and key terms driving discussions in the field. It also noted that researchers with fewer publications may have been overlooked. Bibliometric parameters, including publication counts, citations, total link strength (TLS), and collaboration networks, were examined. Results indicate a steady rise in publications, with significant growth observed from 2000 onwards. The most recent period (2019–2024) alone accounted for 55.6% of the total publications, with a notable 26.5% growth from 2021 to 2022. China leads in both publication volume and TLS, followed by the United States and the United Kingdom. The International Journal of Hydrogen Energy (IJHE) emerged as the top journal with 4653 relevant articles. The analysis reveals a shift in focus from early studies on iron and platinum to a more recent emphasis on nickel‐based catalysts and hydrogen evolution reactions (HER). These findings highlight several challenges, including the need to improve catalyst efficiency, address scalability issues, and develop more sustainable catalytic materials. Future research should focus on advancing catalyst design, optimizing reaction conditions, and enhancing catalytic stability for large‐scale hydrogen production.

Bibliometric analysis is the quantitative examination of bibliographic data. It offers a predominant overview of a study domain that can categorize articles, authors, and publications. This report provides a bibliometric analysis of research on metal-organic frameworks (MOFs) for solid-state hydrogen storage applications. The primary aim of this study is to identify significant research and emerging trends in this subject based on data from the Scopus database. MOFs are highly porous crystals with remarkable adsorption capabilities and are regarded as premier additions for improving solid-state hydrogen storage. MOFs serve as efficient adsorbents owing to their exceptional capacity to absorb gases at low temperatures and elevated pressures via physisorption. A total of 1365 journal publications were obtained from Scopus through a bibliometric review approach. The search criteria were employed to identify publications released between 2003 and 2024. The search began on March 19, 2024. Initially, the study examined the attributes of publications and citations utilizing established bibliometric markers. Secondly, the prominent countries/regions and significant institutions involved in publications concerning MOFs for hydrogen storage were present. Subsequently, this study demonstrates science mapping analysis utilizing the visualization application, VOS Viewer. Co-occurrence analysis of keywords is employed to identify the journal's prevailing subjects and trends. Ultimately, the study examines the journal's prospects based on the aforementioned study. The findings provide valuable insights for researchers to understand the extent of MOF research in hydrogen storage, facilitating the exploration of significant studies and the formulation of topics for future investigations.

Oil reservoirs subjected to a gas recovery technique are commonly challenged by early gas breakthroughs affecting the production rate. Foam is injected to block and divert gas to reservoir sections, however, achieving this mechanism requires stable foam to withstand extreme reservoir conditions, such as temperature, pressure and salinity. In this work, synergy actions between aminopropyltriethoxysilane doped SiO2 nanoparticles (NPs) and MFomax were investigated on rheology, interfacial tension (IFT), wettability, foam stability and quality to reduce gas mobility and enhance oil recovery (EOR). The formulation was guided by optimization, and the foam studies were carried out at optimum concentrations. Core-flood equipment was used to assess the gas mobility reduction factor (MRF) and EOR. From the findings, the foamability of the nanofluid is primarily governed by synergy action between the NPs and MFomax due to significant R2 value (0.9; p < 0.05). Presence of NPs in the formulation resulted in good fluid properties such viscosity and IFT. The nanofoam stability has improved tremendously to 119% relative to MFomax foam. According to the IFT and contact angle, the detachment energy of the NPs (1.4 × 108 eV) is higher than 1 eV suggesting strong adsorption at aqueous interface leading to foam stability. The nanofoam reached a maximum of 50 MRF, while MFomax was below 40 MRF. Subsequently, all the foam descended to lower quality regions around 5 PVI due to the change in foam morphology. Furthermore, the EOR recorded by nanofoam demonstrates a 7% increase on top of MFomax recovery factor. Thus, it can be deduced that the synergy of SiO2 NPs with MFomax offer several benefits in improving the foam stability, quality, MRF and EOR.

As global energy shifts toward sustainable solutions, switching to sustainable energy, particularly those involving energy storage from hydrogen, relies on effective storage technologies. This is necessary for harnessing the potential of hydrogen as a clean energy carrier. This review discussed the latest advancements in materials designed to improve hydrogen storage efficiency, safety, and scalability. The articles reported different storage materials, such as metal hydrides, chemical hydrides, advanced adsorbents, and their challenges and prospects. Developing innovations like nanostructured and hybrid materials are explained, showing how these cutting-edge approaches improve hydrogen kinetics. However, despite the advancements, challenges like feasibility and sustainability remain. Hence, this study discusses these barriers through life cycle assessments and recycling. Moreover, the study offers an understanding of the applications of these materials, illustrating their prospects to simplify a hydrogen economy. Through examining current research and identifying important trends, the article aims to illuminate the way forward for materials science in hydrogen storage applications. The findings highlight the importance of material development and emphasise the collaborative efforts researchers require to realise the potential of hydrogen as a keystone of sustainable energy systems.

The hydrogen economy provides an alternative energy source that can be adopted for a long period. One of its key components is an efficient storage system, which has become a topic of significant research interest to meet the energy goals set by the US Department of Energy (DOE). The US DOE outlines the criteria for suitable hydrogen storage materials, which include cost-effectiveness (specifically $300/kg H 2 by 2025 and ultimately $266/kg H 2 ), moderate operation temperatures (233–358 K), high storage capacity (5.5 wt% 40 g/L 2025, 11 wt%, 79 g/L ultimate), efficient adsorption/desorption cycles, as well as long lifetime operation (1500 cycles). Nanomaterials, particularly porous hollow carbon nanospheres (PHCNs), have attracted considerable attention due to their high storage capacity and unique characteristics, such as high surface area, tunable pore size, and superior kinetics. As a result, PHCNs may help to increase the hydrogen storage capacity of the solid-state hydrogen storage systems. This paper offered an in-depth analysis of the applications of PHCNs in hydrogen storage, comprising their synthesis, characterization methods, infiltration techniques, and the recent progress on the catalytic effects of the materials concerning hydrogen storage. The review concluded with a suggestion for future studies to increase the storage capacity of PHCNs in solid-state hydrogen storage systems comprehensively, as it represents a pivotal step toward a hydrogen-based economy, promoting energy security, and carbon-neutral energy cycles.

The development of new technologies that employ greenhouse gases, such as CO2 and CH4, is becoming more important in the fight against global warming. Catalytic methane dry reforming (MDR) is one straightforward way to reduce CO2 and CH4. In this study, the influence of nickel (Ni) loading on the catalytic performance of fibrous zeolite-Y catalysts (Ni/FHY) for MDR was explored. The study involved the synthesis and testing of Ni/FHY with varying Ni loadings (1 wt% to 10 wt%). The results demonstrate that the metal loading significantly affects the catalysts' performance through metal-support interaction. The catalytic activity showed that the performance of FHY increased with optimum metal loading of 5 wt% where the CO2 conversion increased to 90.3% from 82.2%, and CH4 conversion to 94.2% from 79.6%. The findings suggest that the 5 wt% optimal Ni loading showed the critical role of the metal-support interaction in shaping catalytic properties. Hence, this work provides insights into catalyst optimization for sustainable industrial processes, highlights the importance of the synergistic metal-support interaction, and provides insights into the relationship between Ni content and catalytic behavior. Thus, it offers a basis for optimizing catalysts in MDR and contributes to the advancement of sustainable industrial processes.

Hydrogen is a clean and renewable energy carrier with the potential to address global energy and environmental challenges. However, its practical implementation is hindered by the lack of efficient storage solutions, as hydrogen has a low energy density by volume under ambient conditions. Enhancing hydrogen storage capacity is crucial for enabling its widespread use in applications. Current porous scaffold materials, such as metal-organic frameworks (MOFs) and zeolites, face significant limitations, including low adsorption capacity under practical operating conditions and slow kinetics. Hollow nano-silica (HSS) has emerged as a promising scaffold for hydrogen storage; however, its low capacity hinders practical implementation. To address this, iron (Fe) was incorporated into the HSS for its high capacity, availability and rapid sorption kinetics, which facilitate the dissociation of H2 molecules into atomic hydrogen and enhance chemical interactions between Fe and the HSS surface, thereby increasing the availability of active sites and improving hydrogen adsorption capacity. The resulting HSS exhibited a high surface area of 904 m2/g, with highly developed porous structures with a pore volume of 0.87 cm3/g, and an average pore diameter of 3.1 nm. Different amounts of Fe (3-10 wt%) were incorporated into the HSS. To examine the Fe loading effect, the physicochemical properties such as crystal phase, chemical structure, textural properties, and morphology of the Fe-modified scaffold were analysed. Hydrogen adsorption experiments were subsequently conducted under varying reaction conditions. Following the models of Van't Hoff and Langmuir, the kinetic, as well as thermodynamic analyses, were performed. The characterization findings revealed that the Fe was uniformly distributed within the HSS without causing any alterations to the original structure. Optimal hydrogen adsorption, reaching 2.42 wt%, was achieved with a 5.0 wt% Fe loading, 0.1 g catalyst loading, and at a 523 K temperature. Kinetic results showed that the adsorption followed a pseudo-second-order model, suggesting that the adsorption rate is likely governed by the availability of adsorption sites and the interactions between hydrogen and the adsorbent surface. The 5%Fe-HSS adsorbents demonstrated strong reusability, with less than a 6.4 % loss in activity after four consecutive cycles. These findings suggest that incorporating Fe into the silica structure is an efficient approach for improving the hydrogen adsorption capacity of HSS.

Hydrogen is a promising clean energy carrier, but its practical use is limited by storage challenges. Solid-state storage, particularly using magnesium hydride (MgH2), offers high capacity, though its application is hindered by high decomposition temperatures and slow dehydrogenation kinetics. To increase the storage capacities of MgH2, this study explored the influence of iron (Fe) doped on hollow silica spheres (HSS). Different amount of Fe was doped into the HSS and characterized using different physicochemical characterization techniques. The results show that Fe was successfully incorporated into the MgH2, with the 7 wt% Fe-HSS sample (7Fe-HSS) exhibiting the most significant improvements. The onset dehydrogenation temperature of pure MgH2 was 420 degrees C, while ball-milled MgH2 exhibited a reduced onset temperature of 350 degrees C. MgH2 doped with 3 wt%, 5 wt%, 7 wt %, and 10 wt% Fe-HSS showed onset temperatures of 359 degrees C, 345 degrees C, 320 degrees C, and 335 degrees C, respectively. The MgH2 doped with Fe nanoparticles, exhibited a similar onset dehydrogenation temperature of 320 degrees C. The 7Fe-HSS sample decreased the dehydrogenation temperature by 105 degrees C compared to pure MgH2 and by 30 degrees C compared to ball-milled MgH2. In terms of hydrogen absorption, the 7Fe-HSS composite absorbed 6.09 wt% H2 in 2 min at 320 degrees C, compared to 4.66 wt% for ball-milled MgH2, 4.49 wt% for MgH2-HSS, and 4.45 wt% for MgH2-Fe nanoparticles. Over 60 min, the 7Fe-HSS sample desorbed 4.85 wt% H2 at 320 degrees C, significantly higher than the 0.4 wt% desorbed by ball-milled MgH2, 3.37 wt% by MgH2-HSS, and 4.23 wt% by MgH2-Fe nanoparticles. The hydrogen absorption capacities at 20 min for MgH2-Fe nanoparticles, MgH2-HSS, 3 wt%, 5 wt%, 7 wt%, and 10 wt% Fe-HSS were 4.45 wt%, 4.49 wt%, 4.74 wt%, 5.24 wt%, 6.09 wt%, and 5.17 wt%, respectively. The 7Fe-HSS composite exhibited the highest absorption and desorption rates, with a capacity of 6.09 wt% in 2 min. Additionally, the desorption capacity for the MgH2-Fe nanoparticles, MgH2-HSS, 3 wt%, 5 wt%, 7 wt%, and 10 wt% Fe-HSS samples at 60 min was 4.23 wt%, 3.37 wt%, 4.93 wt%, 5.4 wt%, 4.85 wt%, and 5.27 wt%, respectively, compared to 0.39 wt% for pure ball-milled MgH2. These findings suggest that 7 wt% Fe-HSS is the optimal doping rate for enhancing both hydrogen capacity and desorption kinetics, while higher doping rate, such as 10 wt%, result in decreased storage capacity due to the dead weight of the Fe-HSS. The activation energy for hydrogen desorption was also reduced in all doped samples, with 7Fe-HSS composite showing the lowest value (115 kJ/mol). Furthermore, as compared with pristine MgH2, the 7Fe-HSS has lowered the change in enthalpy by 58.4 kJ/mol. The 7Fe-HSS exhibited five cycles of hy/dehydrogenation, confirming the good cyclability of the synthesized sample. Additional analysis by XRD showed the formation of FeSi2, which indicates the coordination between Fe with the silicon in HSS. It is anticipated that this coordination retains the Fe with HSS, which stops the accumulation of Fe during absorption/desorption. These afford a favourable atmosphere to increase the sorption capacities of MgH2.

This study demonstrates the improved hydrogen storage performance of magnesium hydride (MgH2) through the incorporation of a zirconium-based metal-organic framework (MOF), UiO-66. The addition of UiO-66 significantly enhances the sorption kinetics and reduces the decomposition temperature to below 400 degrees C. Synthesized via a solvothermal route and stabilized by post-calcination at 300 degrees C, UiO-66 exhibits excellent thermal and chemical stability, making it a promising additive for hydrogen storage systems. The MgH2/UiO-66 composite shows an initial dehydrogenation temperature of 262 degrees C, which is 80 degrees C lower than that of milled MgH2. The apparent activation energy is reduced to 85.5 f 5.5 kJ/mol, approximately 45 % of the pristine MgH2, indicating a significantly enhanced reaction pathway. At 250 degrees C, the composite achieves a hydrogen capacity of approximately 6.8 wt% within 3600 s and maintains stable performance over ten consecutive cycles. Particle size analysis via scanning electron microscopy (SEM) reveals finer dispersion and reduced agglomeration in the composite compared to milled MgH2 alone. The MgH2/UiO-66 system effectively functions as a "hydrogen pump," facilitating faster hydrogenation/dehydrogenation kinetics and improved cycling stability. Hence, this study offers fresh insights to expand research and accelerate the advancement of hydrogen energy.