Facile fabrication of CdS/biomass charcoal composites with enhanced removal efficacy of organic pollutants from water

CdS is a widely investigated semiconductor photocatalytic material. Biomass charcoal (BC) attracted attention due to its large specific surface area, high porosity and stability. It emerges as a material boasting widespread utility across domains. However, the high recombination rate and poor mobility of photogenerated carriers hindered the application of CdS. In this study, BC from flaky was synthesized by the calcination method. A set of CdS/BC composites was synthesized using a simple hydrothermal technique. The composites were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmet-Teller (BET), X-ray photoelectron spectroscopy (XPS), ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS), and photoluminescence (PL) to analyze their morphology and optical performance. The experimental results show that the prepared nanocomposites could effectively remove organic pollutants from water bodies. The removal rates of methylene blue (MB), rhodamine B (RhB), and tetracycline (TC) by CdS/BC-50% were as high as 95.58%, 98.99%, and 92.89%. After adding a thimbleful of H
2
O
2
, the degradability of ciprofloxacin (CIP) increased from 60.0% to 86.21%. The photocatalytic performance of CdS/BC was investigated by testing its stability and applicability to different water resources. Based on theoretical calculations and free radical trapping experiments, it was concluded that the main active species in the photocatalytic system was •O
2
-
, while •OH and h
+
play secondary roles. Compared with the single materials CdS or BC, the composites significantly boost the migration and utilization of photo-induced carriers. The calculated results of the work function showed high agreement with the experimental results, further elucidating the photocatalytic mechanism. This study is meaningful for the recycling of agroforestry wastes and water pollution treatment.