Facile fabrication of a NiO/Ag3PO4 Z-scheme photocatalyst with enhanced visible-light-driven photocatalytic activity

Abstract

A Z-scheme photocatalyst can effectively promote the separation of photogenerated carriers, which can retain the strong redox potential and then significantly improve the photocatalytic activity. Herein, active visible-light-driven NiO/Ag₃PO₄ Z-scheme photocatalysts were synthesized using a simple ion-exchange deposition method. The effect of different contents of NiO in NiO/Ag₃PO₄ on photocatalytic activity was investigated. 5% NiO/Ag₃PO₄ was demonstrated to have the highest photocatalytic activity, and the degradation efficiency of rhodamine B (RhB) and methylene blue (MB) reached 97% and 92.6% within 21 min of irradiation by visible light, respectively. Under visible-light illumination, Ag nanoparticles that formed on the NiO/Ag₃PO₄ photocatalyst to create the Z-scheme Ag/NiO/Ag₃PO₄ photocatalytic system played an essential role in developing photocatalytic activity toward the degradation of the organic dyes RhB and MB. Besides, the influence on photocatalytic efficiency of the initial pH, temperature, visible light irradiation time, and photocatalyst dosage is investigated systemically. The mechanism of photocatalytic enhancement was studied using the active substance capture test, transient photocurrent response, EIS and XRD measurements. This work provides a new perspective of the Z-scheme Ag₃PO₄ based heterojunction photocatalytic system and is beneficial for synthesizing more effective Z-scheme junction photocatalysts.