Enhanced photocatalytic H2 production activity by loading Ni complex on flower-like MoS2 nanomaterials

Background: Exploring efficient H-2-production photocatalysts is very important for converting solar energy to chemical energy. Some approaches were developed to prevent the recombination of photogenerated electron-hole pairs, ultimately enhancing the photocatalytic H-2 production activity. Methods: 3D flower-like MoS2 nanomaterials were surface-modified by the Ni complex as the redox mediator to make the composite photocatalysts. This work investigated the effect of zeta potential on the Ni-complex loading, charge separation, and photocatalytic H-2 production activity of MoS2. Significant findings: The Ni-complex with central cation can be loaded on MoS2 with negative zeta potential due to the columb attraction force. The photogenerated carriers can transfer from MoS2 to the central Ni ion of the complex due to the ligands-stabilized multiple oxidation states of Ni, leading to suppressed charge recombination. The FE-TEM mapping and XPS confirm the loading of Ni complex. The photoluminescence, photocurrent response, and EIS tests confirm the improved photoinduced charge separation of the Ni complex-modified photocatalyst. The flower-like microstructure of MoS2 provides a large specific surface area and high light absorption. The H-2 production activity of MoS2-Ni complex photocatalyst (3320 mu mol g(-1) h(-1)) is higher than that of the pristine MoS2 photocatalyst (2576 mu mol g(-1) h(-1)).