Piezo-PhotocatalyticGeneration of H₂ withMoS₂/ZnO/CuFe₂O₄ Nanosheets

Piezocatalytic generation of H₂ is an emerging technology for the collection and application of mechanical energy and the efficient production of sustainable energy nowadays. To enable high-efficiency and low-energy production of H₂, we prepared three MoS₂-based composites (MoS₂/ZnO, MoS₂/CuFe₂O₄, and MoS₂/ZnO/CuFe₂O₄) and used them as the catalysts for the green synthesis of H₂ under mild magnetic stirring conditions (namely, hydraulic driving) to replace the conventional ultrasonic vibration. MoS₂/ZnO/CuFe₂O₄ displayed the highest piezo-photocatalytic activity with a notable H₂ production rate of 3963 μmol g^–1 h^–1 in a 10 vol % methanol–water mixture, accompanied by 1436, 3325, and 2538 μmol g^–1 h^–1 for MoS₂, MoS₂/ZnO, and MoS₂/CuFe₂O₄, respectively, at a stirring speed of 400 rpm (hydraulic gradient, 0.123 s^–1) and 50 W light irradiation. A series of characterizations and analyses were performed to comprehend the insight into the catalytic activity difference and the related reaction mechanisms. The improved piezo-photocatalytic performance of MoS₂/ZnO/CuFe₂O₄ can be ascribed to the enhanced light absorption capability, the reduced electron transfer resistance, and the enhanced separation efficiency of charge carriers, all of which are conducive to H₂ evolution. Holes played a major role in H₂ generation. The H₂ production rate over MoS₂/ZnO/CuFe₂O₄ was far higher than the reported values obtained using ultrasound-driven piezocatalytic slurries. The efficient delivery of hydraulic energy also achieved far lower energy consumption for H₂ production than the reported values. In comparison to the ultrasonic catalytic experiments performed in this work, the hydraulic-driven catalysis was characterized by remarkably lower energy requirements, less noise pollution, and stronger structural stability of the catalysts. This study provides a green and sustainable method for the generation of renewable energy.