Spherical 2-acetylene-(copper metal–organic framework) preparation and efficient photocatalytic hydrogen evolution over combined bimetallic sulfides

Abstract

The charge density and charge transfer resistance of the assisting catalyst have a significant impact on the hydrogen evolution performance of bimetallic sulfides. However, existing mechanistic discussions often overlook the charge density between the two catalysts and whether the assisting catalyst produces enough photo-generated electrons. Here, we propose a simple method for the synthesis of 2-acetylene-(copper metal–organic frameworks) (ACu-MOFs) to improve the hydrogen evolution performance of bimetallic sulfides. Compared to copper metal–organic frameworks (Cu-MOFs), these ACu-MOFs have higher charge density and lower charge transfer resistance. More importantly, the introduction of alkyne-based Cu-MOFs further promotes the hydrogen evolution performance of bimetallic sulfides under 5 W LED light, and XPS is used to determine the difference in charge density between ACu-MOFs and Cu-MOFs and the improvement in contact electron transfer after bimetallic sulfide modification. This work mainly discusses the charge density, charge transfer resistance, and the number of photo-excited electrons generated, and provides a reasonable explanation.