An all-organic TPA-3CN/2D-C3N4 heterostructure for high efficiency photocatalytic hydrogen evolution

Photocatalytic hydrogen evolution has emerged as a promising technology to alleviate energy and environmental issues. Numerous inorganic semiconductors have been designed for efficient photocatalytic hydrogen evolution, but which are generally limited by the heavy metal contamination. All-organic semiconductors have attracted great interest due to the low cost, stable properties and tunable chemical structures. In our paper, TPA-3CN, with the superior donor-acceptor (D-A) structure, was synthesized via the molecular engineering of tri-phenylamine (TPA) and (3-cyano-4,5,5-trimethyl-2(5H)-furanylidene) malononitrile (3-CN). Then an all-organic TPA-3CN/2D-C3N4 heterostructure is formed by linking the TPA-3CN of stronger electron-withdrawing property with two-dimension graphitic carbon nitride (2D-C3N4), which realizes the broader solar absorption compared to the pristine CNS, as well as the quicker electron transfer rate. Significantly, the TPA-3CN/2D-C3N4 shows superior photocatalytic performance of 1558.6 mu mol (twice as 2D-C3N4) under 5 h visible light irradiation (lambda > 400 nm) and its apparent quantum efficiency (AQE) reaches 9.3% at 420 nm. This work offers an innovative opinion for rational development of efficient all-organic photocatalysts for solar energy utilization.