Near Infrared Light-Driven Photoelectrocatalytic Water Splitting over P-Doped g-C3N4

Because infrared (IR) light accounts for almost 50% of solar light, exploring IR-response materials for the photoelectrochemical water-splitting process is of great interest. In this work, phosphorus (P)-doped gC(3)N(4), which was successfully synthesized using a simple sintering method, exhibited an IR light response with 1.4 mu A/cm(2) of current at 1.2 V versus Ag/AgCI under near IR light (>800 nm) irradiation. 1.27 mu mol h(-1 )g(-1) of hydrogen was produced with P/g-C3N4 as a photoanode at 0.6 V versus Ag/AgCI, while a negligible amount of H-2 was detected with a g-C3N4 photoanode. This happened because the introduction of P into g-C3N4 narrowed its band gap from 2.75 to 1.37 eV, leading to a superior IR light response. Furthermore, the P-doping also remarkably improved the charge separation and transfer in g-C3N4.