Bimetallic phosphide NixCo1−xP decorated flower-like ZnIn2S4 for enhanced photocatalytic hydrogen evolution

Abstract

Promoting electron–hole separation and migration is one of the important factors affecting the rate of photocatalytic hydrogen production. Herein, we first prepared Ni_xCo_1−xP modified ZnIn₂S₄ (ZIS) nanoflowers via a low-temperature solvothermal method. Among these catalysts, 2%Ni_0.1Co_0.9P–ZIS exhibited the highest photocatalyst hydrogen production rate of 3839 μmol g⁻¹ h⁻¹ under visible light irradiation (λ > 420 nm), which is 5.4 times and 2.4 times higher than that of pure ZIS (714 μmol g⁻¹ h⁻¹) and 2%Pt–ZIS (1651 μmol g⁻¹ h⁻¹), respectively. The enhancement is due to the formation of close contact between ZIS and Ni_0.1Co_0.9P, which can promote electron–hole separation and migration. Moreover, the hydrogen production rate of Ni_0.1Co_0.9P–ZIS is much higher than that of Ni₂P–ZIS and CoP–ZIS, which is attributed to the synergistic effects of metallic elements. After five photocatalytic cycles, the photocatalytic activity has no obvious change, suggesting excellent chemical stability. This study may provide new ideas for the formation of noble metal-free metal phosphide loading ZIS for photocatalytic hydrogen evolution.