Photocatalytic degradation of naproxen by Bi2MoO6/g-C3N4 heterojunction photocatalyst under visible light: Mechanisms, degradation pathway, and DFT calculation

Abstract

In this research, a 2D/2D Bi₂MoO₆/g-C₃N₄ heterojunction photocatalyst, which can be driven by visible light, was fabricated through a hydrothermal coprecipitation method. Naproxen was used as the target organic contaminant to evaluate the photocatalytic performance of Bi₂MoO₆/g-C₃N₄. The composite photocatalyst showed promoted photocatalytic activity, among which BMO/CN50−50 with a mass ratio 50/50 exhibited the fastest degradation rate, the degradation rate was 3.9 and 2.5 times higher than that of g-C₃N₄ and Bi₂MoO₆, respectively. Scavenger experiments and EPR measurements demonstrated that hole (h⁺) and superoxide radical (O₂⁻) play a leading role in the degradation reactions. Moreover, the degradation pathway was suggested in the light of identified intermediates by Liquid Chromatography-Mass Spectrometry (LC–MS/MS) and DFT analysis. Furthermore, the Quantitative Structure-Activity Relationship (QSAR) analysis was used to evaluate the toxicity of identified degradation intermediates.