Preparation of heterojunction C3N4/WO3 photocatalyst for degradation of microplastics in water

Abstract

In this study, a WO3/g-C3N4 composite photocatalyst was synthesized via a hydrothermal method and characterized for its potential application in photocatalytic H2 generation from PET degradation. XRD analysis revealed that the hexagonal WO3 crystal structure was achieved after 10 h of hydrothermal time, with particles of suitable size for uniform loading on the g-C3N4 surface. SEM images showed the successful loading of WO3 nanorods onto the g-C3N4 surface, significantly increasing the specific surface area. FTIR and UV–vis diffuse reflectance spectroscopy confirmed the formation of a Z-type heterojunction between WO3 and g-C3N4. Photoluminescence measurements indicated a reduced rate of electron-hole pair recombination in the composite. The 30% WO3/g-C3N4 composite demonstrated a high H2 evolution rate of 14.21 mM and excellent stability in PET solution under visible light irradiation. 1H NMR and EPR spectroscopy analyses revealed the degradation of PET into small molecular compounds and the generation of active radicals, including ·O2−, during the reaction. Overall, the WO3/g-C3N4 composite exhibited promising potential for photocatalytic H2 production and PET degradation.