CdS/activated carbon composite for the photocatalysis degradation of tetracycline hydrochloride

The cocatalyst is crucial in promoting charge separation and surface reaction kinetics in the photocatalytic process. In this study, a novel photocatalyst was prepared via a one-step hydrothermal approach, integrating the commonly used semiconductor material cadmium sulfide with activated carbon (AC), forming a Schottky junction between them. The interfacial C-S bond between CdS and AC serves as an atomic-scale electron transfer pathway, lowering the interfacial charge transfer barrier. The synergistic effect of the Schottky junction and the C-S chemical bond improves the efficiency of e-h pair separation and effectively optimizes charge transfer dynamics. Moreover, the specific surface area of activated carbon (AC) is high, which gives the composite a certain adsorption capacity. Experimental results indicate that when the concentration of TCH is 20 mg/L, the photocatalytic degradation effect of CdS/AC(4:1) was the best. The degradation rate of only 5mg could reach 58.67% in 20 min, far exceeding that of CdS. After 60 minutes, the degradation rate was 77.74%, higher than 60.20% of CdS. This study provides reliable guidance for the design and preparation of low-cost and efficient CdS cocatalysts, and opens up a new general solution and possibility for addressing the environmental pollution resulting from the misuse of antibiotics.