Polyvinyl alcohol as solid proton donor to modify g-C3N4via hydrogen bonding enabling efficient photocatalytic H2O2 production from H2O and O2

Abstract

Polyvinyl alcohol (PVA) was used as a solid proton donor to improve the photocatalytic performance of graphitic carbon nitride (CN) for hydrogen peroxide (H₂O₂) production. The modified CN (CN/PVA) was prepared by mixing CN and PVA at room temperature. The H₂O₂ production efficiency of CN/PVA was 5.65 times higher than that of CN in pure water. Photocurrent measurement, electrochemical impedance spectroscopy (EIS), and photoluminescence (PL) analysis proved that PVA increased charge separation of CN. X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared (FTIR) analyses further suggested that PVA acted as the proton donor during H₂O₂ production by interacting with CN via hydrogen bonds. The combination of the charge separation enhancer and proton donor from PVA promoted the sequential two-step single-electron reduction of O₂ for H₂O₂ production. This study paves the way for the modification of g-C₃N₄ with hydroxyl-containing materials as solid proton donors for photocatalytic H₂O₂ production.