Polyvinyl alcohol as solid proton donor to modify g-C 3 N 4 via hydrogen bonding enabling efficient photocatalytic H 2 O 2 production from H 2 O and O 2 .

Polyvinyl alcohol (PVA) was used as a solid proton donor to improve the photocatalytic performance of graphitic carbon nitride (CN) for hydrogen peroxide (H 2 O 2 ) production. The modified CN (CN/PVA) was prepared by mixing CN and PVA at room temperature. The H 2 O 2 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 H 2 O 2 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 O 2 for H 2 O 2 production. This study paves the way for the modification of g-C 3 N 4 with hydroxyl-containing materials as solid proton donors for photocatalytic H 2 O 2 production.