Electron Density Optimization of Molybdenum Disulfide for Enhanced Photocatalytic Hydrogen Production Performance

The heterojunction construction through the effective combination of two metal sulfides can significantly improve the photocatalytic performance in the visible light region. In order to improve the photocatalytic efficiency of molybdenum disulfide (MoS₂), we synthesized a series of CdS/MoS₂ (CM) composites using a simple hydrothermal method. Their photocatalytic activities were evaluated by the photocatalytic hydrogen production. The results showed that the photocatalytic hydrogen production rate of CM composites was significantly enhanced after visible light irradiation, which was attributed to the improvement of visible light absorption capacity, efficient separation of photogenerated carriers, strong photocurrent response, and fast charge mobility. What’s more, sample CM-3 exhibited the highest photocatalytic hydrogen production efficiency of 2809.4 μmol g⁻¹ h⁻¹ compared to pure MoS₂ (0 μmol g⁻¹ h⁻¹) and CdS (81.5 μmol g⁻¹ h⁻¹). Therefore, the successful construction of heterojunction can accumulate much more photogenerated electrons for MoS₂, which is favorable to enhance its photocatalytic hydrogen production. This study provides strong evidence that heterojunction construction can obviously improve the photocatalytic activity.