1D CdS modified 3D zinc cobalt oxide heterojunctions boost solar-driven photocatalytic performance

Abstract

In the process of photocatalysis, semiconductor materials generate photogenerated electrons and photogenerated holes when excited by sunlight, so as to participate in the process of photocatalytic decomposition of water to produce hydrogen. In this work, under the combined action of ultrasonic and electrostatic forces, two semiconductors are successfully coupled through electrostatic self-assembly to effectively avoid the serious phenomenon of sulfide photocorrosion. Through electrochemical and fluorescence characterization experiments, it is confirmed that ZnCo₂O₄/CdS can accelerate the generation and transmission rates of photogenerated carriers. ZnCo₂O₄/CdS greatly increased the activity of the catalyst under simulated sunlight irradiation. With good photocatalytic activity, the hydrogen yield reached 80.71 mmol g⁻¹ within 5 hours, far superior to those of Co₃O₄/CdS and ZnO/CdS. The relative values of the work functions of ZnCo₂O₄(311) and CdS(110) were calculated by DFT. Combined with the position of the conduction band, it was concluded that a new S-scheme induced by an internal electric field was formed at the ZCO/CS-25% contact interface, thus improving the photocatalytic activity.