Photocatalytic degradation of dye using CeO₂/SCB composite catalysts

The main task of the present work is to enhance the photocatalytic degradation efficiency of methylene blue (MB) by using CeO₂/sugarcane bagasse (SCB) composite catalysts. Homogeneous precipitation method was used to synthesis CeO₂-SCB composite catalysts by adding SCB powder to precursor solution of Ce base-metal. The structural analytical data indicated the pure cubic fluorite structure of CeO₂. Morphological images revealed the coating of CeO₂ layer on high surface area of SCB core-shell. The chemical analysis presented spectrum of the Ce 3d in CeO₂/SCB sample existed in the form of the Ce³⁺ and Ce⁴⁺ mixed- valence states. Optical spectra showed the shift of absorption edge towards longer visible region upon supporting CeO₂ with SCB. The main chemical composition of the SCB was K, Ca, and Si. Furthermore, recombination of the photogenerated electrons and holes was identified by photoluminescence techniques (PL), the data suggested inhibition of electron-hole pairs recombination by the cations from SCB loaded in CeO₂/SCB composite. Photocatalytic activity of CeO₂/SCB catalyst was investigated via the degradation of MB under UV-A irradiation. Experimental kinetic data followed the pseudo-first order model. CeO₂ supported with SCB adsorbent had higher photocatalytic activity in dye wastewater treatment compared to the pure CeO₂. The proposed mechanism explaining the high photocatalytic efficiency of CeO₂/SCB was associated with high surface properties and the suppression of recombination of the photogenerated electron-hole pairs by the SCB adsorbent.