Novel ReS2/g-C3N4 heterojunction photocatalyst formed by electrostatic self-assembly with increased H2 production

Abstract

Binary heterostructures (named as CN@Re) composed of ReS2 nanospheres and g-C3N4 nanosheets are constructed by electrostatic self-assembly method. The ReS2 nanospheres were prepared by hydrothermal method and the g-C3N4 nanosheets were treated with surface charge modification. Hydrogen production efficiency of modified CN and CN@Re nanostructures was evaluated in a simulated solar environment. To our surprise, CN5@Re5% exhibits the highest H2 production up to 1823 μmol g−1h−1 of CN5@Rey, which is 3.2 times as high as CN. The improvement of the photocatalytic hydrogen production efficiency of modified CN is attributed to its interaction with the hole sacrificing agent lactic acid, while the improvement of the photocatalytic activity of CN@Re nanostructure is attributed to the efficient electron transfer efficiency between CN and ReS2 and the enhanced light absorption capacity brought by ReS2. In addition, the photocatalytic stability of CN5@Re5% has been studied, which can maintain a stable rate of hydrogen production over four cycles. The apparent quantum efficiency is as high as 4.10% at 365 nm and 2.82% at 420 nm.