Hydrothermal Hydrolyzation-Driven Topological Transformation of Ni–Co Bimetallic Compounds with Hollow Nanoflower Structure for Optimizing Hydrogen Evolution Catalysis

Abstract

Composition screening and structure optimization are two critical factors in improving the electrocatalytic performance of hybrid materials. Herein, we present a straightforward hydrothermal hydrolyzation−topological transformation strategy for the synthesis of a range of Ni−Co bimetallic compounds with a hollow nanoflower structure. Among these Ni−Co compounds, Ni 2 P/Co 2 P hollow nanoflowers (HNFs) exhibit the most impressive electrocatalytic activity for the hydrogen evolution reaction (HER), necessitating only an 153 mV overpotential to achieve a current density of 10 mA cm −2 under alkaline conditions. Importantly, this performance remains stable for over 48 h, indicating exceptional durability. The exceptional catalytic performance of Ni 2 P/Co 2 P HNFs arises from the synergy between the hybrid Ni 2 P/Co 2 P components and the hollow nanoflower structure. The former provides abundant catalytic sites, while electron rearrangement at the heterointerfaces enhances the adsorption/desorption of active species and facilitates electron transfer. The latter contributes to the exposure of catalytic sites, shortening mass and charge transfer routes, and bolstering structural stability during prolonged electrocatalysis. This research offers valuable insights into the screening and optimization of advanced hybrid electrocatalysts, holding significant promise for applications in the emerging field of new energy technologies.

Hollow and Ultrathin Mo-Doped CoP Bamboo-Leaf Nanoarrays for pH-Universal Hydrogen Evolution

“…The peaks at 781.1 and 783.1 eV and the satellite peak at 786.6 eV are attributed to the spin–orbit splitting positions of Co 2p 3/2 . And the peaks at 797.0 and 798.4 eV with one shakeup satellite peak at 803.0 eV can stem from the spin–orbit splitting values of Co 2p 1/2 . − After doping the Mo element, Mo possesses less electronegativity than Co. The electron will metastasize from Mo to Co and produce undersaturated Co.…”