Multi-heterojunction photocatalysts based on WO3 nanorods: Structural design and optimization for enhanced photocatalytic activity under visible light

摘要

The construction of multiple heterojunctions holds promise for enhancing the performance of semiconducting photocatalysts. It can improve charge separation and extend light absorption range via component optimization. Herein, we report the structural design and optimization of a (WO3-Pt)/TiO2 multi-heterojunction photocatalyst based on WO3 nanorods and Pt and TiO2 nanoparticles. The multi-heterojunction-based photocatalyst displayed high activity for the degradation of Rhodamine B dye (RB), phenol, and gaseous acetaldehyde under visible light excitation. Moreover, its activity was higher than single-heterojunction-based photocatalysts, P25 and P25/Pt. The higher performance of the multi-heterojunction-based photocatalyst was attributed to the synergistic effect of efficient conduction band electrons transfer at the WO3/Pt interface and valence band holes transfer at the WO3/TiO2 interface. The photocatalytic performance of the multi-heterojunction-based photocatalyst was also dependent on the location of the loaded Pt nanoparticles. Pt surface loading on WO3, as opposed to loading on the TiO2 surface, was more beneficial in maximizing the photocatalytic activity.