Self-assembled BiOCl/Ti3C2Tx composites with efficient photo-induced charge separation activity for photocatalytic degradation of p-nitrophenol

Cocatalysts play an important role in increasing the photogenerated electron-hole separation rate of catalytic materials. Here, we selected a novel 2D material Ti3C2Tx (T-x = -OH, -O) as a cocatalyst and synthesized BiOCl/Ti3C2Tx (named as BT-n n = 0, 0.5, 1.0, 2.0, 4.0) composite materials by electrostatic self-assembly. We carefully characterized the structure, morphology and photoelectric performance of the composites, finding that we successfully synthesized 2D/2D BiOCl/Ti3C2Tx materials. The photocatalytic performance of the composites was evaluated by degradation of p-nitrophenol as a pollutant under simulated illumination. Among the composites obtained, BT-2.0 showed the best photocatalytic performance; specifically, its removal rate reached 97.86% and its degradation rate was about 3.3 times that of BT-O. Free radicals in the photocatalytic process were tested by electron paramagnetic resonance, which showed that superoxide radicals and holes are the most active free radicals in the system due to the higher photogenerated electron separation efficiency of BT-2.0. Therefore, constructing a heterojunction with Ti3C2Tx as a cocatalyst can improve the photocatalytic activity of BiOCl, which may provide new insights into the selection of novel co-catalytic materials in the field of photocatalysis.