Efficient Photocatalytic Overall Water Splitting Induced by the Giant Internal Electric Field of a g-C3 N4 /rGO/PDIP Z-Scheme Heterojunction.

A graphitic carbon nitride/rGO/perylene diimide polymer (g-C3 N4 /rGO/PDIP) Z-scheme heterojunction is successfully constructed to realize high-flux charge transfer and efficient photocatalytic overall water splitting. A giant internal electric field in the Z-scheme junction is built, enabling the charge separation efficiency to be enhanced dramatically by 8.5 times. Thus, g-C3 N4 /rGO/PDIP presents an efficient and stable photocatalytic overall water splitting activity with H2 and O2 evolution rate of 15.80 and 7.80 µmol h-1 , respectively, ≈12.1 times higher than g-C3 N4 nanosheets. Meanwhile, a notable quantum efficiency of 4.94% at 420 nm and solar-to-hydrogen energy-conversion efficiency of 0.30% are achieved, prominently surpassing many reported g-C3 N4 -based photocatalysts. Briefly, this work throws light on enhancing the internal electric field by interface control to dramatically improve the photocatalytic performance.