Enrichment of graphitic-N in nitrogen-doped photoreduced graphene oxide as highly efficient photocatalyst for mineralization of volatile organic compounds

Exposures to air pollutants such as volatile organic compounds cause severe health effects. Photocatalysis is a technology that uses light energy and a photocatalyst to perform chemical reactions, such as the oxidation of indoor VOCs. Herein, a nitrogen-doped photoreduced graphene oxide (NPRGO) photocatalyst was synthesized via a facile solution-based photoirradiation method. The photoirradiation method allowed us to tailor the nitrogen (N) dopant concentration and configuration. The NPRGO photocatalyst demonstrated remarkable photocatalytic properties, such that 100 mg/m³ of gaseous methanol under UV-A irradiation was completely mineralised into harmless CO₂ and water at a rate of 0.376 h⁻¹. This is attributed to the substantial content of graphitic- N groups on the NPRGO, which induced a high free-electron carrier density and a strong n-type conductivity. These advantageous properties of the NPRGO consequently improved the separation of photoinduced charge carriers, therefore enhancing the photodegradation of VOCs. This work demonstrates a new approach for the development of metal-free NPRGO photocatalyst in air pollution remediation.