Electrocatalytic water splitting, which is driven by renewable energy input to produce oxygen, has been widely regarded as a promising strategy in the future energy portfolio. The two-dimensional structure based on CoOOH nanosheets is easy to handle in the preparation process, low in cost, and has a small overpotential during water decomposition. Therefore, CoOOH two-dimensional materials have been widely used as electrocatalysts for the oxygen evolution reaction (OER). In this paper, we summarize the application of two-dimensional CoOOH nanosheets in the field of oxygen production from electrocatalytic water splitting. First, the different preparation methods of two-dimensional CoOOH nanosheets are briefly introduced. The structure–activity relationship of the two-dimensional CoOOH catalyst was analyzed from different viewpoints, such as doping, defects, etc. Finally, different catalytic mechanisms of CoOOH-based catalysts are discussed, and studies at the density functional theory (DFT) level are also provided to support the above mechanisms. To improve the readability of this review, a concise overview at the end of each section is given to illustrate some of the characteristics and trends of the studies in the corresponding part. The opportunities and challenges of two-dimensional CoOOH as an electrocatalyst in the future are summarized in the Conclusion section. This work will provide new insights and perspectives to the readers to understand the role of CoOOH nanosheets in the OER process.

The photo-Fenton degradation mechanism of CoFe ₂ O ₄ with H ₂ O ₂ and PMS as oxidants and some effective strategies to improve the catalytic performance.

Fe-based amorphous/nanocrystalline alloys exhibit excellent soft magnetic properties, including high saturation magnetic flux density (B_s), high permeability, low coercivity (H_c), and low magnetostriction. They are utilized in distribution transformers, transformers, reactors, and other devices. As green, energy-saving, and environmentally friendly materials, their application fields have more possibilities. In this paper, the development history, composition design principle, heat treatment process, magnetic properties, and annealing brittleness of Fe-based amorphous/nanocrystalline alloys are introduced.