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 Ag2Mo2O7 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 Ag2Mo2O7 by electrostatic self‐assembly. The hydrogen‐producing capacity of the composite catalyst GDY/Ag2Mo2O7 reaches up to 8156.6 μmol g−1 h−1, what is more, the photocatalytic hydrogen‐producing capacity of Ag2Mo2O7, GDY, and GDY/Ag2Mo2O7 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/Ag2Mo2O7 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/Ag2Mo2O7 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.