Facile one-pot synthesis of Mg-doped g-C3N4 for photocatalytic reduction of CO2

Graphitic carbon nitride (g-C3N4) has attracted wide attention due to its potential in solving energy and environmental issues. However, rapid charge recombination and a narrow visible light absorption region limit its performance. In our study, Mg-doped g-C3N4 was synthesized through a facile one-pot strategy for CO2 reduction. After Mg doping, the light utilization efficiency and photo-induced electron–hole pair separation efficiency of the catalysts were improved, which could be due to the narrower band gap and introduced midgap states. The highest amounts of CO and CH4 were obtained on Mg-CN-4% under ultraviolet light illumination, which were about 5.1 and 3.8 times that of pristine g-C3N4, respectively; the yield of CO and CH4 reached 12.97 and 7.62 μmol g−1 under visible light irradiation. Our work may provide new insight for designing advanced photocatalysts in energy conversion applications.