The effect of indium doping on the hydrogen evolution performance of g-C3N4 based photocatalysts†
Abstract
Doping graphitic carbon nitride (g-C3N4) with metal ions has been developed as a facile approach to improve its visible light photocatalytic performance towards hydrogen evolution via water splitting. In this work, a series of In3+ doped g-C3N4 (In-g-C3N4) photocatalysts were prepared via in situ thermal copolymerization by using a mixture of dicyanamide and InCl3 as precursors. It was proposed, for the first time, that the In3+ ions were doped into g-C3N4 in a unique quasi-interlayer fashion, which contributed to tunable separation efficiency and migration ability of the photogenerated carriers by simply adjusting the amount of In3+ doping without changing the band edge of g-C3N4. The In-g-C3N4 photocatalyst doped with an optimal amount of indium ions, i.e., 2.18 wt%, exhibited a hydrogen evolution rate of 1.35 mmol h−1 g−1, 17 times that of pristine g-C3N4 (0.08 mmol h−1 g−1), attributed to the synergistically promoted separation and migration of the photogenerated charge carriers.