Interface regulation of Pt quantum dots doped nickel phosphide and cobalt hydroxide to promote electrocatalytic overall water splitting

The transition metal phosphates are earth-abundant minerals that have been shown to perform well in electrocatalytic water splitting, whereas these catalysts still tend to have excessively high overpotentials and slow kinetics in HER and OER processes. In the present work, hybrid catalysts consisting of Pt quantum dots doped NiP (NiP-Pt) nano-embroidery spheres and Co(OH)2 nanosheets were successfully prepared by two-step electrodeposition method. The excellent catalytic performance of the catalyst relies principally on the synergistic interaction between NiP and Pt quantum dots. Additionally, the NiP-Pt exhibits strong electronic interactions at the interface with Co(OH)2. Consequently, the catalyst has a strong catalytic performance in terms of HER and OER catalytic performance. In terms of HER, an overpotential of only 40 mV is required when the current density reaches 10 mA cm−2, corresponding to a Tafel slope of 49.85 mV·dec−1. At the same time, the catalyst also performs well at OER, with a current density of 10 mA cm−2 at an overpotential of 186 mV and a Tafel slope of 53.049 mV·dec−1 much less than most electrocatalysts. This study involving electrodeposition and doping of quantum dots provides a new idea for the efficient synthesis of fundamental HER and OER bifunctional catalysts.