Simplified synthesis of direct Z-scheme Bi2WO6/PhC2Cu heterojunction that shows enhanced photocatalytic degradation of 2,4,6-TCP: Kinetic study and mechanistic insights

For this work, we employed n-type Bi 2 WO 6 and p-type PhC 2 Cu to formulate a direct Z-scheme Bi 2 WO 6 /PhC 2 Cu (PCBW) photocatalyst via simplified ultrasonic stirring technique. An optimal 0.6PCBW composite exhibited the capacity to rapidly photodegrade 2,4,6-TCP (98.6% in 120 min) under low-power blue LED light, which was 8.53 times and 12.53 times faster than for pristine PhC 2 Cu and Bi 2 WO 6 , respectively. Moreover, electron spin resonance (ESR), time-resolved PL spectra, and quantitative ROS tests indicated that the PCBW enhanced the separation capacity of photocarriers. It also more readily associated with dissolved oxygen in water to generate reactive oxygen species (ROS). Among them, the ability of PCBW to produce ·O 2 - in one hour was 12.07 times faster than for pure PhC 2 Cu. In addition, the H 2 O 2 formation rate and apparent quantum efficiency of PCBW are 10.73 times that of PhC 2 Cu, which indicates that PCBW not only has excellent photocatalytic performance, but also has outstanding ROS production ability. Furthermore, Ag photodeposition, in situ X-ray photoelectron spectroscopy (XPS) and density functional theory (DFT) calculations were utilized to determine the photogenerated electron migration paths in the PCBW, which systematically confirmed that Z-scheme heterojunction were successfully formed. Finally, based on the intermediate products, three potential 2,4,6-TCP degradation pathways were proposed.