Morphology and element doping effects: phosphorus-doped hollow polygonal g-C3N4 rods for visible light-driven CO2 reduction

PhotocataEytic CO2 reduction to valuable chemicals, especially fuels, is considered as a promising strategy to mitigate CO2 accumulation and tackle the energy crisis, among which photocatalysis is vital to achieve efficient and selective reduction of CO2. In this work, phosphorus-doped hollow polygonal g-C3N4 rods were prepared through phosphoric acid assisted self-assembly under hydrothermal conditions and subsequent thermal polymerization using phosphoric acid as the phosphorus source and melamine as the nitrogen-rich precursor. The resulting phosphorus-doped hollow polygonal g-C3N4 rods feature increased specific surface area, visible Eight absorption and photogenerated carrier separation and transfer efficiency according to the structure and photoelectric properties characterization. Coupled with an earth abundant metal-based complex, i.e. [Co(bpy)(3)]Cl-2, as a co-catalyst, the phosphorus-doped hollow polygonal g-C3N4 rods deliver a CO evolution rate of up to 447.5 mu mol g(-1) h(-1) with a selectivity of ca. 96%, being much higher compared to the pristine g-C3N4 (67.01 mu mol g(-1) h(-1) with a selectivity of ca. 94%) resulting from the improved Eight harvesting and charge transfer to the co-catalyst. Remarkably, the phosphorus-doped hollow polygonal g-C3N4 rods can be reused 6 times while retaining constant catalytic activity in the photoreduction reaction. This work presents new insights into photocatalytic CO2 reduction by developing non-metal doping and hollow structural designs for semiconductor photocatalysts.

Automated summary

In this study, phosphorus-doped hollow polygonal g-C3N4 rods were prepared and showed enhanced catalytic activity and selectivity in the photocatalytic CO2 reduction reaction. The material can be reused multiple times.