Controlled Oxygen Doping in Highly Dispersed Ni-Loaded G-C3n4 Nanotubes for Efficient Photocatalytic H2o2 Production

Hydrogen peroxide is both a key component in several industrial processes and a promising liquid fuel. H2O2 can be produced by solar photocatalysis as a suitable strategy to convert and store solar energy into chemical energy. Here we report an oxygen-doped tubular g-C3N4 with uniformly dispersed nickel nanoparticles for efficient photocatalytic H2O2 generation. The hollow structure of the tubular g-C3N4 provides a large surface with a high density of reactive sites and efficient visible light absorption during photocatalytic reaction. The oxygen doping and Ni loading enable a fast separation of photogenerated charge carriers and a high selectivity toward the two-electron process during the oxygen reduction reaction (ORR). The optimized composition, Ni4%/O0.2tCN, displays an H2O2 production rate of 2464 mmol g-1·h-1 , which is eightfold higher than that of bulk g-C3N4 under visible light irradiation, and achieves an apparent quantum yield of 28.2% at 380 nm and 14.9% at 420 nm