In-situ generated CQDs-doped Ni(OH)2 nanosheets with high photoelectric activity on nickel foam for efficient hydrogen evolution reaction in alkaline solution

It is of great significance for a clean energy system to develop novel non-noble catalysts toward the alkaline hydrogen evolution reaction (HER). Herein, CQDs-doped Ni(OH) 2 nanosheets generated on nickel foam were fabricated by a feasible method using Ni-MOF as precursor. Notably, the alkali etching treatment can open the spatial structure of Ni(OH) 2 and expose more active sites, thereby improving the electrocatalytic active surface area . Meanwhile, introduced CQDs can be acted as the charge carrier and accelerate the charge transfer. As a result, the Ni(OH) 2 -CQDs nanosheets showed excellent electrocatalytic performance in HER under alkaline condition, and an overpotential of 101 mV for OER over Ni(OH) 2 -CQDs/NF electrode can be realized at a current density of 10 mA/cm 2 . More significantly, embedding CQDs can effectively boost the photocatalytic activity of Ni(OH) 2 . Thus, light radiation can enhance the performance of Ni(OH) 2 -CQDs/NF electrode in HER, and the overpotential of Ni(OH) 2 -CQDs/NF electrode for HER can reduce to 90 mV under light irradiation . Furthermore, the Ni(OH) 2 -CQDs/NF electrode displayed great HER stability, and the possible mechanism of photo-assisted electrochemical HER was also proposed. All in all, current work will share some valuable insights into preparation and application of catalysts in HER.