Synthesis and characterization of Sb2S3-CeO2/chitosan-starch as a heterojunction catalyst for photo-degradation of toxic herbicide compound: Optical, photo-reusable, antibacterial and antifungal performances.

Heterostructured Sb2S3-CeO2 composites and Sb2S3-CeO2 on chitosan-starch nanocomposites have been provided with chemical manner. The characterization was performed by various instruments such as, scanning electron microscopy, Brunauer-Emmett-Teller surface area measurements, X-ray diffraction analysis, energy dispersive X-ray spectrometer and UV-Vis absorption spectroscopy. The mean crystallite sizes of CeO2, Sb2S3-CeO2 and Sb2S3-CeO2/chitosan-starch are 25.12, 51.11 and 64.12 nm, respectively. The energy band gaps of CeO2, Sb2S3-CeO2 and Sb2S3-CeO2/chitosan-starch are appraised to be 3.01, 2.41, and 2.23 eV, respectively. Photocatalytic properties of the as-prepared products for degradation of Paraquat as a toxic organic compound are investigated under UV light irradiation at room temperature. The Sb2S3-CeO2 and Sb2S3-CeO2/chitosan-starch exhibited high photocatalytic performance. Moreover, the possible mechanism of photocatalytic degradation for Paraquat was proposed. The photocatalyst as hydroxide form existing in the product provides more OH during the degradation process, as well as influences the band gap of the product due to present the electron-hole pairs. The optimum effects such as time and pH were obtained 7 and 30 min for photo-degradation process. The antibacterial and fungicidal property of Sb2S3-CeO2/chitosan-starch nanocomposites was investigated and demonstrates good efficiency in antimicrobial efficiency compared to CeO2, and Sb2S3-CeO2.