Dual-phase NiSe–NiSe2 constructs rapid hydrogen evolution channels by phase control achieve high-performance water electrolysis catalyst

With the growing global demand for clean energy, water electrolysis for hydrogen production is seen as an efficient method for generating clean energy. The interface between two phases possesses special catalytic activity due to large lattice mismatches and strain concentration. It's a challenge to precisely tailor the multiphase interfaces of catalysts. Herein, the phase interface of NiSe–NiSe 2 was precisely controlled through a hydrothermal method. NiSe 2 crystals are uniformly distributed on NiSe nanosheets and form heterojunction structures. This uniformly distributed interfaces significantly improve the catalyst's Hydrogen evolution reaction (HER) performance, achieving an overpotential of only 32 mV and a Tafel slope of 39.83 mV dec −1 at 10 mA cm −2 in 1 M KOH. The dual-phase interface induces electronic reconfiguration and the elevated d-band center of Ni, resulting in selective adsorption of H∗ and non-adsorption of H 2 O and OH − at the interface, which facilitates H∗ adsorption and H 2 desorption, thereby creating numerous rapid hydrogen evolution channels. Additionally, an anion exchange membrane water electrolyzer was assembled using NiSe–NiSe 2 as the cathode, which achieved a current density of 1 A cm −2 at 1.92 V in a 1 M KOH solution. This approach of introducing a special hydrogen evolution interface through composite dual-phase structures is promising for future low-energy, high-efficiency water electrolysis for hydrogen production.