Efficient photocatalytic H2 production and Cr(VI) reduction using a Cu2-xSe/ZnSe heterojunction

Photocatalytic technology provides key benefits in utilizing solar energy for H 2 production and pollutant removal, making the pursuit of efficient photocatalysts a vital area of focus. Herein, a novel p-n heterojunction photocatalyst was synthesized by loading ZnSe nanoparticles onto Cu 2−x Se nanoplates, creating an internal electric field that facilitates the efficient separation of charge carriers and significantly enhances photocatalytic activity. The 14 % Cu 2−x Se/ZnSe nanocomposite exhibits excellent photocatalytic performance, achieving an H 2 production rate of 1846 μmol·g −1 ·h −1 , roughly 34 times that of pure ZnSe. Additionally, the Cr(VI) reduction rate constant of nanocomposite was 0.0277 min⁻¹ , which is 20 times and 5 times higher than those of ZnSe and Cu 2−x Se, respectively. The Cu 2−x Se/ZnSe photocatalyst demonstrated exceptional stability and reusability during multiple cycles of H 2 production and Cr(VI) reduction. An in-depth examination of experimental data and density functional theory (DFT) calculations led to proposing a potential mechanism. This work introduces a simple synthesis method for ZnSe-based photocatalysts, offering a novel approach for the effective application of solar energy in environmental and energy fields.