Blossom-like CoSe_2-x nanorods: A highly efficient piezo-photocatalytic material for H₂O₂ generation

The facile one-step hydrothermal method successfully synthesized a superb piezo-photocatalytic CoSe_2-x with extraordinary performance towards piezo-photocatalytic H₂O₂ generation. CoSe_2-x exhibits an enhanced piezoelectric and photocatalytic activity upon stimulation inside the ultrasound-assisted photocatalytic system. Experimental analysis proves that CoSe_2-x possesses properties of piezo-photocatalysis that are crucial for the outstanding performance. The unique morphology, band-structure position, and surface defects helped substantially enhance the piezo-photocatalytic performance and facilitate the photogenerated species separation. The catalyst system has been optimized with different hydrothermal preparation conditions. CoSe_2-x synthesized for 24 h achieves a high yield of H₂O₂ up to 1536 mM⋅g⁻¹⋅h⁻¹ during the piezo-photocatalytic ORR process. The proposed mechanism of piezo-photocatalyst discussed in generating H₂O₂ could establish a new point of view for selenide-based materials in many research fields.