For the aim of achieving the carbon-free energy scenario, green hydrogen (H₂) with non-CO₂ emission and high energy density is regarded as a potential alternative to traditional fossil fuels. Over the last decades, significant breakthroughs have been realized on the alkaline hydrogen evolution reaction (HER), which is a fundamental advancement and efficient process to generate high-purity H₂ in the laboratory. Based on this, the development of the practical industry-oriented anion exchange membrane water electrolyzer (AEMWE) is on the rise, showing competitiveness with the incumbent megawatt-scale H₂ production technologies. Still, great challenges lie in exploring the electrocatalysts with remarkable activity and stability for alkaline HER, as well as bridging the gap of performance difference between the three-electrode cell and AEMWE devices. In this perspective, we systematically discuss the in-depth mechanisms for activating alkaline HER electrocatalysts, including electronic modification, defect construction, morphology control, synergistic function, field effect, etc. In addition, the current status of AEMWE is reviewed, and the underlying bottlenecks that impede the application of HER electrocatalysts in AEMWE are summarized. Finally, we share our thoughts regarding the future development directions of electrocatalysts toward both alkaline HER and AEMWE, in the hope of advancing the commercialization of water electrolysis technology for green H₂ production.

Electrocatalytic nitrate reduction (NO₃RR) is a promising route for sustainable ammonia synthesis under mild conditions. The widely studied Co-based catalysts undergo significant reconstruction due to nitrate oxidation and electric-field reduction during NO₃RR, leading to activity degradation. To address this issue, we develop a Co₆Ni₄ heterostructured catalyst that consists of interlaced metallic Co and Ni domains. Operando X-ray absorption spectroscopy and other in-situ characterization techniques, in conjunction with theoretical calculations, demonstrate that Ni domains function as electron reservoir, which transfer electrons to Co and prevent the accumulation of high-valence Co. Besides, the abundant Co/Ni interfaces also facilitate the NO₃RR process, thereby achieving a NH₃ Faraday efficiency of 99.21%, a NH₃ yield rate of 93.55 mg h^-1 cm^-2, and a NO₃RR stability of 120 h. Our analyses delve into the underlying causes of the observed stability of metallic Co in Co₆Ni₄ and provide compelling evidence that the discrepancy between the adsorption quantity of NO₃^- on catalyst surface and the corresponding electron supply is a pivotal factor influencing the reconstruction process.

Efficient and durable electrocatalysts for the oxygen evolution reaction (OER) are essential for advancing water splitting technologies, which enable sustainable hydrogen production. The integration of amorphous oxide supports with metal single atoms offers a promising strategy to precisely tuning the electronic structure and improving the exposure of active sites. Here, we report an amorphous NiMoO_x support anchored with Ru single atoms (denoted as a-RNMO), which achieves a low cell voltage of 1.78 V at 1 A cm⁻² and noteworthy durability in an anion exchange membrane water electrolyzer. Time-resolved operando Quick X-ray absorption spectroscopy reveals rapid Mo leaching followed by structural reconstruction, culminating in the NiOOH formation. Theoretical calculations suggest a likely “complementary amorphous-electronic” mechanism. It shows that the amorphous structure exposes more active sites and favors the adsorption of intermediates, while Ru single atoms finely modulate the electronic structure. These valuable insights highlight the design of high-performance OER electrocatalysts based on metal single atoms anchored on amorphous oxides.

The therapeutic efficacy of nanozymes, which have wide applications in cancer treatment, can be enhanced by various biomimetic design strategies, from structural and process mimicry to advanced functional biomimicry.

This review highlights iron-based nanozymes including iron oxides, single-atom nanozymes, and MOFs that induce ferroptosis via ROS generation and Fenton chemistry, achieved by POD-, CAT-, OXD- and SOD-like activities.