Construction of highly efficient carbon cloth-supported S-scheme Co3O4/AgIO4 heterojunction for photocatalytic degradation of Rhodamine B organic dye

Abstract

The development of effective methods for the synthesis of supported photocatalysts instead of dispersive powdery photocatalysts has received great attention. Herein, a flexible visible-light-driven carbon cloth-supported Co3O4/AgIO4 composites was successfully prepared by combining electrodeposition and chemical coprecipitation method. After 40 min of visible-light illumination, 99.2 % of the rhodamine B can be degraded by carbon cloth-supported Co3O4/AgIO4 composites with electrodeposition duration of 50 min, showing a highest reaction rate constant of 10.5 × 10−2 min−1 which exceeds that of CC/Co3O4 and CC/AgIO4 by a factor of 58.39 and 2.67 times, respectively. The band structures of the samples were studied by valence band X-ray photoelectron spectroscopy, ultraviolet photoemission and theoretical calculations. The capture experiments confirmed that positive holes and the superoxide radicals are two main reactive species participating in the degradation of rhodamine B. The excellent photocatalytic reactivity can be attributed to the successful construction of S-scheme heterojunction between Co3O4 and AgIO4. The Co3O4/AgIO4 heterojunction not only inhibited the rapid recombination of charges but also reserved the oxidation and reduction ability of the holes in the valence band of AgIO4 and electrons in the conduction band of Co3O4. The work is of great significance in the development of carbon cloth-supported photocatalysts with good recyclability for practical applications of wastewater treatment.