Directed self-assembled pathways of 3D rose-shaped PtNi@CeO2 electrocatalyst for enhanced hydrogen evolution reaction

Abstract

The development of high electrocatalytic activity and low-cost Pt-containing catalyst is highly feasible for hydrogen evolution reactions under alkaline conditions. In this study, a series of three-dimensional (3D) rose-shaped cerium (IV) oxide (CeO2)-supported Pt and Ni alloy nanocomposite catalysts were prepared by a direct solvothermal method (PtxNiy @CeO2), and the catalytic activity of the prepared catalysts in hydrogen evolution reactions was studied. The experimental results show that the rose-shaped CeO2 as a carrier can provide abundant oxygen vacancies, and when combined with Pt and Ni, it will trigger the rearrangement of metal electrons. At the same time, this special structure can provide a larger specific surface area and expose more active sites. Bimetallic catalysts have higher hydrogen evolution reaction (HER) activity than monometallic catalysts due to the interaction between metals. In the composite catalyst with a molar ratio of Pt to Ni of 1:1 (Pt1Ni1 @CeO2), electrons are transferred from Ni to Pt. At this time, the catalyst exhibits the most excellent HER catalytic performance. Exhibits low HER overpotential (59 mV) and Tafel slope (56.50 mV dec−1) at a current density of 10 mA cm−2. In addition, the composite catalyst exhibits distinguished long-term electrochemical stability within 15 h. This work provides new possibilities for the effective combination of rare earth oxides and Pt-based materials as high-efficiency HER electrocatalysts under alkaline conditions.