Multifarious function layers photoanode based on g-C 3 N 4 for photoelectrochemical water splitting

Abstract We report on a novel g-C 3 N 4 /TiO 2 /Co-Pi photoanode combining a TiO 2 protection layer, Co-Pi hole capture layer, and g-C 3 N 4 light-absorption layer layer for photoelectrochemical (PEC) water splitting to generate hydrogen for the first time. This new photoanode with three function layers exhibits enhanced PEC performance with a photocurrent density of 0.346 mA·cm −2 at 1.1 V (vs. RHE), which is approximately 3.6 times that of pure g-C 3 N 4 photoanode. The enhanced PEC performance of g-C 3 N 4 /TiO 2 /Co-Pi photoanode benefits from the following: (1) excellent visible light absorption of g-C 3 N 4 ; (2) stable protection of TiO 2 to improve the durability of g-C 3 N 4 film; and (3) photogenerated holes capture Co-Pi to separate photogenerated electron-hole pairs efficiently. This promising multifarious function layers structure provides a new perspective for PEC water splitting to generate hydrogen.