An amorphous nickel boride-modified ZnxCd1−xS solid solution for enhanced photocatalytic hydrogen evolution

Abstract

In this work, the rational design of amorphous Ni_xB as a co-catalyst for the modification of Zn_xCd_1−xS was achieved. First, Ni_xB was prepared by the redox method and Zn_xCd_1−xS was synthesized by the hydrothermal method. Then, the electrostatic self-assembly method was used to complete the coupling of Ni_xB and Zn_xCd_1−xS. The experimental results of H₂ production showed that when the mass ratio (wt%) of Ni_xB in Ni_xB/Zn_xCd_1−xS was 7 wt%, it had the highest activity, and the hydrogen production could reach 1521 μmol under irradiation with light for 5 h. The hydrogen production activity of the composite catalyst was 4.75 times higher than that of pure Zn_xCd_1−xS. The improvement in the photocatalytic activity can be attributed to the following aspects: (i) UV-vis DRS showed that the addition of Ni_xB increased the absorption of visible light; (ii) the PL, TRPL, IT, EIS and LSV experiments further proved that the composite catalyst had excellent photoelectrochemical properties; (iii) the zeta potential results indicated that the electrostatic attraction between Ni_xB and Zn_xCd_1−xS provided favorable conditions for the rapid transfer of electrons. This work shows that amorphous Ni_xB has a prominent effect on the modification of Zn_xCd_1−xS, which provides more ways for the study of photocatalytic H₂ evolution.