Mineralization and toxicity reduction of the benzophenone-1 using 2D/2D Cu2WS4/BiOCl Z-scheme system: Simultaneously improved visible-light absorption and charge transfer efficiency

Developing excellent photocatalysts to mineralize pollutants and reduce toxicity is an urgent problem in current environment purification research. Here, we synthesized a novel 2D/2D Cu2WS4/BiOCl Z-scheme system by a facile solvent mixing method and characterized the samples by various analytical methods. Compared with 3D/2D, the close contact surface of the 2D/2D catalyst endows it with extremely fast charge transfer and a large number of active sites, a Z-scheme system process strong electronic interaction and efficient charge separation, resulting in the high photocatalytic performance of the 2D/2D Cu2WS4/BiOCl Z-scheme system. As expected, The 15% 2D/2D Z-scheme Cu2WS4/BiOCl possessed the highest rate constant 1.14 x 10(-1) min(-1) in the degradation of benzophenone-1 (BP1), which are 8, 5 and 4 times greater than that of BiOCl (1.36 x 10(-2) min(-1)), Cu2WS4 (2.27 x 10(-2) min(-1)) and 15% 3D/2D Cu2WS4/BiOCl (2.6 x 10(-2) min(-1)), respectively. Meanwhile, the practicability of Cu2WS4/BiOCl was studied by the influence of relevant real water matrix on photocatalytic degradation of BP1. In addition, the result of density functional theory calculations demonstrated that the 2D/2D Cu2WS4/BiOCl system has faster charge transferability and closer integration than that of the 3D/2D system, which further confirms that the close 2D interface is conducive to charge transfer at the interface. Nine potential degradation products were identified as intermediates, and extremely significant toxicity reduction during the degradation process was confirmed by an ECOSAR prediction and zebrafish acute toxicity test. Compared with gene expression, the hatching rate and survival rate of zebrafish embryo are more sensitive and considered to be better choices for toxicity assessment.