Synergistic role of dual-metal sites (Ag–Ni) in hexagonal porous g-C3N4 nanostructures for enhanced photocatalytic CO2 reduction

Harnessing solar energy to convert CO₂ into hydrocarbon fuels presents a viable strategy for mitigating CO₂ emissions. For effective photocatalytic CO₂ reduction (PCR), it is crucial to optimize both photoinduced and chemical reactions synergistically. In this research, hexagonal porous g-C₃N₄ (CN) nanostructures with Ag–Ni dual metal site loadings were synthesized using a hydrothermal method followed by calcination, significantly enhancing PCR efficiency. The optimal results demonstrated significant production rates of 77.65 μmol/g for CO and 17.89 μmol/g for CH₄, showcasing exceptional photocatalytic performance. This enhanced performance is attributed to several factors: the high porosity of the g-C₃N₄, the synergistic effects at the Ag–Ni dual metal sites, and the increased surface area. Detailed experimental measurements, coupled with comprehensive density functional theory (DFT) calculations, have elucidated the mechanisms underlying the significant improvements in the photocatalytic activity of the developed catalyst. This study not only demonstrates an effective approach for converting CO₂ into valuable hydrocarbon fuels but also significantly advances our understanding of complex photocatalytic systems, providing insights that could guide future developments in this field.