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.