Constructing 0D/2D Z-Scheme Heterojunction of CdS/g-C3N4 with Enhanced Photocatalytic Activity for H2 Evolution

Abstract

0D/2D Pt-C3N4/CdS heterojunction photocatalyst were fabricated with CdS quantum dots interspersed on g-C3N4 nanosheets via successive ionic layer absorption process. The obtained Pt-C3N4/CdS Z-scheme heterojunction with Pt cocatalyst deposited on g-C3N4 nanosheets exhibited H2 production rate of 35.3 mmol g−1 h−1, which is 3.1 times higher than that of Pt-CdS/C3N4. The enhanced photocatalytic activity are attributed to the Z-scheme charge carrier transfer mechanism with stronger redox ability. The photocatalytic mechanism of the CdS/g-C3N4 composite is investigated and demonstrated in this work. It may provide unique insights to design 0D/2D Z-scheme heterojunction photocatalyst systems using a facile method for highly efficient H2 production. Schematic illustration of charge transfer modulated by the metal cocatalyst selective deposition on heterojunction-type II (a) and direct Z-Scheme mechanisms (b) over the C3N4/CdS heterostructure composites under visible light irradiation.