Microwave-assisted solvothermal in-situ synthesis of CdS nanoparticles on bacterial cellulose matrix for photocatalytic application

摘要

Bacterial cellulose (BC) is a unique nanofibrous biomaterial, and crystalline cadmium sulphide (CdS) is regarded as one of the most attractive visible light-driven photocatalysts. In this study, a BC@CdS nanocomposite for photocatalytic degradation of organic dye methylene blue (MB) was prepared with a facile and highly efficient strategy. The nanocomposite was prepared through a designed "anchoring-reacting-forming" pathway. SEM images showed that the BC-alcogel was the best matrix for nano-fabrication on which nanosized CdS particles were homogeneously distributed (approximately 100 nm). The results from FT-IR, XRD and XPS revealed that the CdS nanoparticles, mainly cubic and hexagonal crystallite, are attached to the BC fibers via coordination effect. The BC-supported adsorbent photocatalytic material was easy to be recycled and followed a new "adsorption-accumulation-degradation" mechanism of photocatalytic degradation. The results showed BC matrix had a strong adsorption effect on MB molecules, which improved local concentration of MB and promoted the rate of photocatalytic reaction. This novel adsorbent photocatalytic nanocomposite material (contained 12.4% CdS, about 0.91 mg for degradation experiment) possessed highly efficient photocatalytic activity with 77.39% removal of MB after 180 min visible light irradiation (the degradation rate was 28.3% mg(-1) h(-1)), and exhibited satisfactory cyclic utilization with slight attenuation. Therefore, BC@CdS nanocomposite is a novel promising candidate as adsorbent photocatalysts with visible light response.