Graphdiyne/Ag₂Mo₂O₇ S‐Scheme Heterojunction for Photocatalytic Hydrogen Production Promoted with Efficient Photogenerated Carriers Separation

Abstract

Inhibiting the recombination of photoexcited hole–electron pairs is the crucial for efficient hydrogen‐producing by photocatalytic water splitting under visible light. Although Ag 2 Mo 2 O 7 has excellent photoelectrochemical properties and strong morphological plasticity, its hydrogen‐producing activity is inhibited due to its low separation efficiency of photogenerated carriers and small photoresponse range. Therefore, graphdiyne (GDY) is prepared using alkynyl anions and compounded with Ag 2 Mo 2 O 7 by electrostatic self‐assembly. The hydrogen‐producing capacity of the composite catalyst GDY/Ag 2 Mo 2 O 7 reaches up to 8156.6 μmol g −1 h −1 , what is more, the photocatalytic hydrogen‐producing capacity of Ag 2 Mo 2 O 7 , GDY, and GDY/Ag 2 Mo 2 O 7 is investigated by in situ X‐ray photoelectron spectroscopy, electrochemical testing, fluorescence analysis, and density functional theory calculation. The consequences display that the composite catalyst GDY/Ag 2 Mo 2 O 7 shows the best fluorescence quenching effect and the highest photocurrent response intensity. In the final analysis, the preeminent photocatalytic hydrogen‐producing performance of the composition GDY/Ag 2 Mo 2 O 7 is due to the establishment of type S heterojunction, and the migration rate of photogenerated electrons is increased and the migration path is shortened. This contributes a practical tactics to effectively enhance the capacity of photocatalytic hydrogen‐producing by solving the problem of serious recombination of photogenerated carriers.