Cuina Yang

Transition metal selenides, due to their excellent conductivity and low cost, have become promising catalysts alternative materials. However, monocomponent catalysts still face challenges such as the scarcity of active sites and high adsorption energy barriers. In this study, NiSe₂/CoSeO₃ composite catalysts were synthesized through a one-step hydrothermal method. The electrocatalytic activity of the nickel foam, NF–NiSe₂, and NF–NiSe₂/CoSeO₃ catalysts in the oxygen evolution reaction (OER) was systematically compared. A series of electrochemical tests demonstrated the superior performance of the NF–NiSe₂/CoSeO₃ catalyst at various current densities. Notably, at higher current densities, the catalyst exhibited a lower overpotential and a higher electrocatalytic efficiency. The density functional theory (DFT) analysis revealed that the NiSe₂/CoSeO₃ composite effectively optimized the electronic conductivity, surface active site distribution, and charge transfer rate, thereby enhancing the electrocatalytic performance. The study further revealed that the synergistic effect of the NiSe₂/CoSeO₃ composite catalyst significantly boosted the OER efficiency, providing an important theoretical basis for the future optimization of electrocatalysts and showing broad application potential.

Piezo-/photocatalysis combining piezoelectric effect and photocatalysis based on a PZT/Ag₂O heterojunction was used for degrade dyes.

A CuO/bentonite composite photocatalyst was prepared to fully utilize the adsorption capacity of bentonite and the photocatalytic activity of CuO. CuO and bentonite were chosen as a photocatalyst due to the excellent optical property of CuO and large specific surface area of bentonite, together with their high stability and low production cost. The sample was characterized by XRD, SEM, and BET. The effects of several factors on degradation process were investigated such as dosage of H₂O₂, irradiation time, pH of the solution, and dosage of catalyst. The optimum conditions for decolorization of methylene blue solution by CuO/bentonite were determined. Under optimal conditions, the decolorization efficiency of methylene blue by a 1.4% CuO/bentonite (400 °C) composite photocatalyst under visible irradiation at 240 min reached 96.98%. The degradation process follow edpseudo-second-order kinetics. The photocatalytic mechanism is discussed in detail. This composite structure provides a new solution to the cycle and aggregation of the photocatalyst in water.