The oxygen evolution reaction (OER) is the key anodic reaction in water electrolysis for hydrogen production. Herein, a novel two-dimensional (2D) CoS/Co-MOF composite electrocatalyst was successfully synthesized using a post-synthesis method. The as-synthesized 2D CoS/Co-MOF composite employed as an OER electrocatalyst exhibits an exceptionally low overpotential of 327 mV at a current density of 100 mA cm⁻², considerably outperforming most reported transition metal sulfide catalysts (e.g., NiS/MOFs: 368 mV, Co₉S₈@MoS₂/Co-MOFs: 350 mV). Furthermore, the resulting CoS/Co-MOF OER electrocatalyst demonstrates exceptional stability, maintaining stable catalytic activity after 20 h of constant-current operation and exhibiting minimal degradation after 30 days of air exposure. In addition, a systematic investigation of key parameters (e.g., the thioacetamide (TAA) content and reaction temperature) was conducted to identify the optimal process conditions. Moreover, the catalytic mechanism of CoS/Co-MOF electrocatalyst was further elucidated based on density functional theory (DFT) calculations. These results reveal that the introduction of CoS can modulate the d-band centre of the CoS/Co-MOF, thereby optimizing adsorption free energy and reducing the overpotential. This synergy between the structure and optimized synthesis parameters advances the sustainable development of high-performance OER electrocatalysts. This work offers a feasible method for designing efficient and durable electrocatalysts that can facilitate large-scale applications of water electrolysis for hydrogen production.

Currently, water electrolysis has attracted significant attention as an environmentally benign hydrogen production technology. However, its practical implementation was substantially hindered by the sluggish kinetics of the four-electron/proton-coupled oxygen evolution reaction (OER), necessitating the development of cost-effective OER catalysts to improve overall reaction efficiency. This review systematically elucidated the OER mechanisms, with particular emphasis on the reaction pathways and key intermediates in different electrolytes. Focusing on alkaline media, recent advances in OER catalysts were comprehensively summarized, including noble metals, transition metal-based materials, monometallic metal-organic frameworks (MOFs), bimetallic MOFs, MOF derivatives and MOF-based composites. Future perspectives were proposed regarding mechanistic investigations and performance optimization strategies, aiming to guide the design of next-generation OER catalysts.

Facile synthesis conditions, abundant hierarchical porosity, and high space–time yields (STYs) are prerequisites for the commercial application of zeolitic imidazolate frameworks (ZIFs). However, these prerequisites are rarely achieved simultaneously. Herein, a green and versatile strategy to rapidly synthesize hierarchically porous ZIFs (HP-ZIFs) was developed using an alkali as a deprotonating agent. The synthesis conditions were room temperature and ambient pressure in an aqueous solution, and the synthesis time could be reduced to 1 min. The produced HP-ZIFs had hierarchically porous structures with mesopores and macropores interconnected with micropores. The STY for HP-ZIFs was up to 9670 kg m⁻³ d⁻¹, at least 712 times the previously reported values. In addition, the porosity and morphology of the produced HP-ZIFs could be fine-tuned by controlling the synthesis parameters (e.g., reaction time, molar ratios, metal source, and alkali source). Compared with conventional ZIFs, the adsorption performance of the as-synthesized HP-ZIFs for p-xylene and n-hexane was significantly improved. Positron annihilation lifetime spectroscopy (PALS) was utilized to study the pore properties, and the adsorption behavior of HP-ZIFs on guest molecules was investigated using density functional theory (DFT) simulations. This strategy shows significant promise for the large-scale industrial production of desirable HP-ZIFs for adsorption applications.