Constructing bifunctional Co3O4@Ni3S2 as pair of electrooxidations catalysts with superior photoelectrocatalytic efficiency for water purification

Abstract

Finding a bifunctional heterostructure catalyst that can act as a pair of electrooxidations to decompose refractory organic dyes in wastewater is an important issue. Herein, we succeeded in preparing a Co3O4@Ni3S2 heterostructure by the two-step hydrothermal method as promising bifunctional catalysts that function simultaneously as the anode and cathode. Remarkably, the optimized bifunctional Co3O4@Ni3S2-3.0 electrodes exhibit a degradation rate of ~ 95% and acceptable stability for practical usage, which can be attributed to its low Tafel slope, large electrochemically active surface area, and low charge transfer resistance. Free radical capture experiments using auxiliary probe molecular fluorescence experiments suggest that the Z-scheme heterostructure of Co3O4@Ni3S2-3.0 is proposed to promote charge separation and produce the main active species. The rational design of this work--a new strategy for establishing a highly efficient bifunctional pair of electrooxidation heterostructure catalysts of Co3O4@Ni3S2-3.0 with a Z-scheme band structure—will lead to other catalysts designs.