Search Results (924)

The nickel-derived metal–organic framework (MOF), Ni-BTB, synthesized from 4,4′,4″-benzene-1,3,5-tribenzoic acid (H₃BTB), was investigated as a multifunctional platform for enhanced energy applications including production and storage. In catalytic hydrogen generation by NaBH₄ hydrolysis, Ni-BTB attained a hydrogen generation rate (HGR) of 4640 mL H₂/g•min with 1 mg of catalyst, with an activation energy of 76.44 kJ/mol. Under optimized reaction conditions (60 °C, 20 mg catalyst, and 1 g NaBH₄), the HGR increased to 9542 mL H₂/g•min, while exhibiting high recyclability throughout four successive cycles. As a supercapacitor electrode, Ni-BTB achieved a specific capacitance of 156 F/g at 1 A/g and showed remarkable cycling stability, maintaining its capacitance after 10,000 charge–discharge cycles. Furthermore, Ni-BTB exhibited exceptional electrocatalytic activity for oxygen evolution reaction (OER), requiring only 106 mV overpotential to achieve 10 mA/cm², offering a time-of-flight (TOF) of 0.0585 s⁻¹ and demonstrating significant operational longevity of at least 12 h. These findings underscore Ni-BTB as a durable, reusable, and adaptable material for hydrogen production, energy storage, and electrocatalytic applications. Full article

Catalytic materials are central to the advancement of hydrogen generation technologies, playing a pivotal role in enabling sustainable, carbon-neutral energy systems. Hydrogen can be produced via electrochemical water splitting, thermochemical reforming, or photocatalysis—each imposing unique performance requirements on catalysts in terms of activity, selectivity, stability, and efficiency. While traditional noble metals (e.g., platinum, ruthenium, iridium) provide benchmark catalytic activity, their widespread use is hindered by scarcity, high cost, and limited long-term durability. Consequently, researchers have increasingly focused on earth-abundant alternatives such as transition metals (Ni, Co, Fe, Mo), alloys, metal oxides, carbides, sulfides, nitrides, and carbon-based systems. Among these, two-dimensional materials, particularly the MXene family, have attracted significant attention due to their metallic conductivity, layered structure, and tunable surface chemistry. These features enable rapid charge transfer and abundant active sites, making MXenes and related nanostructured catalysts promising for both the Hydrogen Evolution Reaction (HER) and Oxygen Evolution Reaction (OER) across a wide range of electrochemical conditions. Parallel efforts have integrated novel semiconductors, plasmonic nanomaterials, and hybrid heterostructures to improve the efficiency of solar-to-hydrogen energy conversion. This paper reviews the main types of catalytic materials used in hydrogen production, explains their design strategies and structure–performance relationships, and discusses key engineering challenges such as integrating renewable energy sources, scaling up manufacturing, and ensuring long-term durability in real-world systems. Future research goals are also highlighted, including the development of affordable non-noble catalysts, enhancing catalyst stability through surface and defect engineering, and coupling hydrogen production with circular economy principles, all of which are essential to making hydrogen generation more efficient, scalable, and cost-effective as the world transitions to clean and sustainable energy. Full article

Metal-free electrodes are essential to promote electrochemical reactions, the core of sustainable energy resources. In search of better carbon-based electrode materials, we have explored several spatial arrangements of boron (B) within proximity in the graphene lattice, as evident in recent experimental observations. Multi-boron substitution enriches sites by tuning electronic structure and strengthens binding of key intermediates of oxygen reduction, oxygen evolution, and hydrogen evolution reactions facilitating electrocatalytic performance. Our optimal B-doped site shows near thermo-neutral H adsorption ($\Delta G_{H^{*}}$∼$\pm 0.4\mathrm{eV}$), consistent with experiments. The overpotentials are highly sensitive to the dopant motifs and the spread among configurations shows that experimentally accessible multi-B doping can serve as a practical active site engineering knob to achieve optimized multi-functional performance. In parallel, we find that specific multi-B configurations selectively capture and pre-activate NO_x (NO/NO₂) under ambient conditions while retaining weak affinity for NH₃. These sites also interact with SO₂ and related hazardous species, enabling selective air filtration and targeted NO_x control within the electrocatalytic scope of this study. Full article

Open Educational Resources (OER) have emerged as a cost-effective alternative to traditional commercial textbooks in higher education, towards the goal of alleviating college students’ financial burden of educational expenses. However, mixed findings about the influences of the integration of OER on student learning are present. To address the gap, this study investigated whether student motivation in OER served as a latent factor that impacts their academic achievement in online asynchronous courses offered in public universities. Particularly, this study (N = 247) implemented an advanced person-centered approach—stepwise latent class analysis—to profile student achievement goals in an OER-based course and examined their relationships with academic achievement. The 7-point Likert responses were collapsed into three categories to address sparse response distributions. The analysis identified four latent classes based on students’ responses to a validated survey aligned with the 2 × 2 achievement goal theory framework, including highly ambitious, cautious, strategic, and low-goal learners. Subsequent analysis revealed that these four latent classes showed differences in academic achievement as well as task value and expectancy beliefs. The implications of these results for researchers and college instructors and future research directions are discussed. Full article

Hollow nanostructures have emerged as a pivotal class of nanomaterials in electrocatalysis, offering intrinsic advantages such as high surface-to-volume ratios, reduced density, and economical utilization of precious metals. However, the prevailing research paradigm has predominantly focused on the external shell characteristics while overlooking the decisive role of the interior cavity microenvironment. This review introduces a novel conceptual framework that positions the rational engineering of the cavity microenvironment—encompassing mass transport dynamics, localized electronic structure modulation, active site exposure, and structural stability—as a unified design principle for next-generation electrocatalysts. We systematically elucidate how precise control over cavity geometry, composition, and interfacial properties can optimize electrocatalytic performance for oxygen reduction (ORR), oxygen evolution (OER), and hydrogen evolution (HER) reactions. By correlating microenvironmental parameters with catalytic metrics, we establish structure–property–performance relationships and highlight recent breakthroughs. Finally, we outline future challenges in achieving atomic-level precision in cavity design, understanding dynamic evolution under operating conditions, and scaling up synthesis for industrial applications. Full article

The water–energy–carbon (WEC) nexus provides a systems framework for minimizing trade-offs among water security, energy reliability, and carbon mitigation. Within this framework, waste-derived biochar catalysts offer a circular pathway that simultaneously valorizes residues, reduces process energy demand, and supports carbon management through stable carbon storage and catalytic co-benefits. This review consolidates recent advances in biochar-based catalysts engineered from agricultural, industrial, municipal, and sludge-derived wastes, highlighting how feedstock selection and thermochemical processing, namely pyrolysis, hydrothermal carbonization (HTC), and torrefaction, as well as activation and post-modification (heteroatom doping and metal/metal-oxide incorporation) govern structure–property–performance relationships. The synthesized catalysts have been widely applied in water and wastewater treatment, including adsorption–advanced oxidation process (AOP) hybrids, Fenton-like systems, peroxydisulfate/persulfate (PS) and peroxymonosulfate (PMS) activation, photocatalysis, and the removal of emerging contaminants. They have also demonstrated strong potential in energy conversion processes such as the hydrogen evolution reaction (HER), oxygen reduction and evolution reactions (ORR/OER), biomass reforming, and carbon dioxide (CO₂) conversion. In addition, these materials contribute to carbon management through sequestration pathways, avoided emissions, and life cycle assessment (LCA)-based sustainability evaluations. Finally, we propose a WEC-aligned design roadmap integrating techno-economic analysis (TEA), LCA, and scale-up considerations to guide next-generation biochar catalysts toward robust performance in real matrices and deployment-ready systems. Full article

Perovskite oxide photoanodes are attractive for alkaline water oxidation but are commonly limited by interfacial recombination and sluggish charge transfer. Here we enhance anisotropic SrTiO₃ (STO) photoelectrodes via Al doping by simple yet effective one-step hydrothermal method and identify an optimal composition at 4% Al. In 0.1 M NaOH (pH 13) under simulated AM 1.5G illumination, 4% Al:STO exhibits 2 times enhancement in photocurrent density and 80% increase in electrochemically active surface area compared with the pristine SrTiO₃, as evidenced by the reduced charge-transfer resistance and enlarged light–dark photocurrent gap. together with a markedly reduced interfacial impedance, indicating accelerated charge extraction and transfer. Band-structure analysis shows a positive shift in flat-band potential and slight band-gap narrowing after Al doping, providing more favorable carrier energetics. Steady-state and time-resolved photoluminescence further demonstrate strong PL quenching and a prolonged carrier lifetime for 4% Al:STO. ECSA analysis suggests increased electrochemically accessible surface sites at the optimal doping level. Overall, moderate Al doping synergistically tunes defects, band energetics, and interfacial kinetics to improve STO photoanodes for solar water splitting. Full article

CoNi layered double hydroxides (CoNiLDHs) were successfully synthesized on nickel foam (NF) using a hydrothermal method. X-ray diffraction (XRD) analysis confirmed the formation of a well-defined hydrotalcite-like phase, including a strong (003) peak, indicating layered stacking. Scanning electron microscopy (SEM) revealed a 3D hierarchical nanosheet structure resembling flower-like arrays, which was further supported by EDS mapping showing a uniform distribution of Co, Ni, and O. Electrochemical studies demonstrated excellent OER activity, with a low overpotential of 188 mV at 10 mA/cm² and a Tafel slope of 97.48 mV/dec, inferring rapid reaction kinetics. Furthermore, the material exhibited a significant electrochemical surface area (ECSA) compared to bare NF. Chronoamperometry over 24 h confirmed the operational durability catalyst, stabilizing around 7–8 mA/cm², validating its potential as a cost-effective and efficient OER electrocatalyst in alkaline media. Full article

Ethylene glycol oxidation reaction (EGOR) is a promising anodic process to reduce the cell voltage compared with the oxygen evolution reaction (OER). Using ethylene glycol (EG) obtained from biomass-derived streams—such as cellulose, hemicellulose or lignocellulosic intermediates—and polyethylene terephthalate (PET) waste contributes to the development of circular-economy models. This study investigates EGOR on a non-noble NiCo bimetallic electrode, focusing on the effects of temperature and current density. The presence of EG reduces the initial potential by 240 mV at 25 °C, with a further 60 mV decrease at elevated temperatures, while the catalyst maintains high formate selectivity (>65%) across the tested conditions. Faradaic efficiency peaks at 100 mA cm⁻² due to the full oxidation of formate to CO₂ or the competing OER at higher current densities. There are no significant discrepancies between simulated and experimental faradaic efficiencies, although the presence of terephthalic acid (TPA) affects the shift in the electrode potential. Overall, these results highlight the relevance of EGOR for future applications in which EG derived from recycled plastics and renewable biomass can be electrochemically valorized within integrated biorefinery frameworks. Full article

We report the facile synthesis of hierarchical spiked cobalt selenide (Co_0.85Se) microcrystals grown on nickel foam (NF) via a hydrothermal method followed by selenization. Derived from cobalt hydroxyl fluoride (Co(OH)F) microcrystals, the resulting Co_0.85Se structures exhibit a robust architecture with well-defined spikes that offer abundant active sites and promote efficient charge transfer, thereby enhancing their electrocatalytic bifunctional activity toward the oxygen evolution reaction (OER) and urea oxidation reaction (UOR). The Co_0.85Se/NF electrode delivers low overpotentials of 357 mV for OER and 236 mV for UOR at 100 mA cm⁻². Furthermore, it exhibits a small Tafel slope (34.3 mV dec⁻¹) and excellent durability for 24 h at 100 mA cm⁻² during UOR. This simple and cost-effective strategy highlights the potential of hierarchical spiked Co_0.85Se microcrystals as highly efficient electrocatalysts for urea-assisted OER and related sustainable energy conversion applications. Full article

Magnetic-field-assisted electrocatalysis offers a powerful route to enhance the oxygen evolution reaction (OER) by coupling spin-dependent effects with magnetohydrodynamic phenomena. Here, we present a unified study of cobalt ferrite (CoFe₂O₄)-based nanofilms, elucidating the combined roles of rare-earth doping, nanoparticle size, film morphology, and electrode substrate magnetism on OER performance under external magnetic fields. The effect of UV-light irradiation is also investigated. CoFe₂O₄ and yttrium-doped CoFe₂O₄ nanoparticles were synthesized via thermal decomposition and self-combustion routes, yielding single-domain particles with distinct structural and magnetic properties, and assembled into homogeneous nanofilms using the Langmuir–Blodgett technique. Electrocatalytic measurements in alkaline media reveal that intrinsic OER activity is primarily governed by film compactness and charge-transfer efficiency, while the magnitude of magnetic-field-induced enhancement depends on the magnetic response of both the nanofilms and the supporting electrode. Ferromagnetic substrates promote enhanced catalytic activity under magnetic fields, whereas diamagnetic substrates can exhibit suppressed performance. Across all systems, the strongest enhancement is observed when the magnetic field is applied parallel to the electrode surface, reflecting the combined effects of spin polarization and Lorentz-force-driven mass transport. UV-light irradiation is also evaluated as an external stimulus to promote the reaction. Our findings establish a comprehensive framework for designing magnetically assisted OER electrocatalysts and demonstrate that magnetic-field effects can rival or complement rare-earth doping or UV-light irradiation, offering a sustainable pathway toward high-efficiency water oxidation. Full article

The oxygen evolution reaction (OER) is the rate-limiting step in alkaline water electrolysis for hydrogen production. Owing to their earth abundance and high intrinsic activity, transition metal-based catalysts (TMBCs) have emerged as promising alternatives to noble-metal catalysts, with defect engineering recognized as an effective strategy for enhancing OER performance. This review systematically summarizes recent advances in regulating alkaline OER activity of TMBCs through vacancy defects, including anion vacancies, cation vacancies, and divacancies. First, the alkaline OER mechanism, key performance evaluation parameters, and activity descriptors are briefly introduced. The formation mechanisms and regulation strategies of different vacancy types are discussed, with emphasis on how vacancy defects enhance OER performance by modulating electronic structures, optimizing active sites, and tuning adsorption–desorption behaviors of reaction intermediates. In addition, the advantages and application scenarios of various characterization techniques for vacancy defects are summarized. Finally, current challenges are identified, and future research directions are proposed. This review provides theoretical and practical references for the rational design of high-performance transition metal-based OER catalysts and the large-scale advancement of alkaline water electrolysis for hydrogen production. Full article

Background/Objectives: Older adults with neurocognitive and psychological disorders are often institutionalized in nursing homes, which negatively affects well-being and mood, and may accelerate cognitive decline. Immersive virtual reality (VR) is a promising non-pharmacological countermeasure, but VR-headset discomfort limits its usability in this population. Therefore, this study examined the tolerability and feasibility of an immersive VR room, which provides customizable interactive environments projected across four walls at 360° and enables shared experiences, to enhance positive affect and engagement in nursing home residents. Methods: Twenty nursing home residents were initially enrolled, and nineteen completed five 10 min sessions in the immersive VR room accompanied by a caregiver. State positive and negative effects were assessed using the visual analogue scale (VAS) and the Observed Emotion Rating Scale (OERS), and participants’ verbal feedback was collected during and after the sessions. Results: VAS scores indicated that VR room immersion was feasible and well-tolerated, with most participants feeling secure and experiencing increased positive affect during and just after the sessions. OERS scores and observations revealed frequent expressions of pleasure, interest, and active engagement with both the VR environments and the caregiver. Participants’ reports valued the enjoyable and relaxing experience provided by immersion in the VR room, noting the realism and aesthetics of the environments and nature-related elements, which allowed them to travel virtually and evoke personal memories. Conclusions: Immersive VR room sessions were well tolerated, enhanced positive affect, and may support cognitive functioning by fostering active engagement and social interaction. Given that this is a feasibility study with a small cohort and short follow-up, the present findings should be considered preliminary and confirmed in larger, controlled, longer-term studies. Full article

In zinc electrowinning, industrial Pb-Ag anodes have inherent limitations, including high oxygen evolution overpotential and rapid corrosion. This study constructs Ti-Ti₂N-PbO₂-CeMnO_x composite anodes to overcome these shortcoming, Electrochemical characterization revealed enhanced performance with a reduced overpotential (725 mV 50 mA cm⁻²) and lower Tafel slope (102.92 mV dec⁻¹) in the standard zinc electrowinning electrolyte, indicating faster oxygen evolution kinetics compared to commercial benchmarks. Analysis of the XPS test revealed an increase in the content of Mn³⁺, which helps enhance the OER catalytic activity of the electrode. The Ti/Ti₂N/α/β-PbO₂-CeMnO_x (abbreviation: CMO) composite anode exhibited superior corrosion resistance with an extended service life of 53 h under accelerated polarization at 2 A cm⁻². This durability enhancement is attributed to the combined effects of the Ti₂N interlayer and CMO incorporation, which effectively mitigate anode degradation through passivation inhibition. The developed fabrication strategy enables the production of dimensionally stable anodes (DSAs) with balanced electrocatalytic activity and operational stability, showing promising potential for industrial zinc electrowinning applications. Full article

Mechanistic interpretation in transition metal electrocatalysts for water splitting, particularly for the oxygen evolution reaction (OER), remains challenging despite major advances in operando spectroscopy, isotope labelling, and electrochemical analysis. Mechanistic claims are frequently supported by incomplete or overinterpreted evidence, leading to persistent ambiguity in active site identification, rate-limiting step assignment, and pathway discrimination. This review adopts a claim-centric framework that organises experimental approaches around the specific mechanistic assertions they aim to support, rather than cataloguing catalyst classes or performance metrics, and formalises this perspective as a decision-guided framework for mechanistic validation. We critically assess how techniques such as isotope labelling, operando spectroscopy, and electrokinetic analysis can and cannot substantiate claims related to adsorbate-versus lattice-oxygen-mediated pathways, reconstruction-defined active phases, and dynamic surface behaviour. Application of this framework to common mechanistic archetypes in OER electrocatalysis shows that surface reconstruction and condition-dependent pathway switching limit static mechanistic assignments, and that single-technique interpretations are rarely definitive. By clarifying the minimum evidentiary standards required for common mechanistic claims, this review aims to promote more rigorous, transparent, and falsifiable mechanistic analysis, supporting durable progress beyond descriptor-driven correlations and isolated performance benchmarks. Full article