Promoting photocatalytic performance of Bi2WO6 nanosheet incorporated with a 3D-Succulent plant-like SrMoO4 modified by Ag under simulated sunlight

In order to improve the photocatalytic performance of Bi2WO6, the self-assembled succulent plant-like SrMoO4 is successfully incorporated with Bi2WO6 nanosheet through co-precipitation method. Ag nanoparticles are introduced to Bi2WO6/SrMoO4 (SMO/BWO) composite to form a ternary 5 wt%Ag/4.3 wt%SMO/BWO heterojunction photocatalyst, and further promote photocatalytic activities. SEM images of the as-prepared samples demonstrate that part of the BWO nanosheet with Ag nanoparticles are adhered and embedded onto the 3D-succulent plant-like SMO. The obtained transient photocurrent, photoluminescence spectroscopy (PL) and electrochemical impedance spectroscopy (EIS) show that the separation efficiency of photo-generated electron (e- ) and hole (h+) pair of the ternary photocatalyst is the highest. As a result, the 5 wt%Ag/4.3 wt%SMO/BWO heterojunction photocatalyst has highly better off photocatalytic performance under simulated sunlight for methylene blue (MB). According to the obtained apparent reaction rate constants, the photocatalytic performance values are determined to be 4.94 and 8.78 times than of the bare BWO and SMO, respectively. Furthermore, a Z-scheme electron transfer mechanism is proposed to elucidate the enhanced photodegradation performances of the 5 wt% Ag/4.3 wt%SMO/BWO heterojunction photocatalysts, as well consider the effect of local surface ion resonance of Ag nanoparticles.

Automated summary

The study successfully improved the photocatalytic performance of Bi2WO6 by incorporating SrMoO4 and Ag nanoparticles, forming a ternary heterojunction photocatalyst. The ternary catalyst showed significantly enhanced separation efficiency of photo-generated electron-hole pairs, leading to greatly improved photocatalytic activity for methylene blue degradation under simulated sunlight. The proposed Z-scheme electron transfer mechanism and the effect of local surface ion resonance of Ag nanoparticles contribute to the enhanced photodegradation performances of the ternary photocatalyst.