Graphitic Carbon Nitride−γ-Gallium Oxide (GCN-γ-Ga₂O₃) Nanohybrid Photocatalyst for Dinitrogen Fixation and Pollutant Decomposition

Dinitrogen (N2) is earth’s most abundant form of gas, and its photofixation into ammonia (NH3) is a sustainable solution. Solar-driven photoreduction of N2 to NH3 at ambient temperature and pressure is a benign technique to generate renewable fuels; however, the NH3 production is currently limited to noble-metal-containing systems that operate at high pressure and temperature. Herein, we assess the light-driven photoreduction of N2 to NH3 and dye degradation activity of γ-gallium oxide (γ-Ga2O3) hierarchical nanostructures deposited on two-dimensional graphitic carbon nitride (GCN). Using the advantage of surface nitrogen vacancies of GCN and interfacial coupling of GCN-γ-Ga2O3 nanohybrid catalysts, we were able to photoreduce N2 to NH3 under light irradiation at ambient conditions and effectively degrade various organic dyes. The N2 photoreduction using GCN-γ-Ga2O3(10) nanohybrid yielded NH4+ production rate of 355.5 μmol L–1 h–1, which is 1.6-fold and 16-fold higher than GCN and γ-Ga2O3, respectively. The underlying highlights of the hybrid catalyst presents economical route to aqueous-phase N2 reduction into NH3 via heterogeneous photocatalysis under solar light.