Visible light-enable oxidation and antibacterial of zinc oxide hybrid chitosan photocatalyst towards aromatic compounds treatment

A solar-driven, ZnO-supported chitosan (ZnO/CS) photocatalyst has been formulated, with the aim of enhanced photocatalytic activities with a simple acidic mixing process and the gel solidification method. ZnO/CS, with a narrow band gap (2.89 eV) and macro-porous structure was confirmed under Ultra Violet Diffuse Reflection Spectra (UV DRS) and Transmission Electron Microscopy (TEM), respectively. The Field Emission Scanning Electron Microscopy (FESEM) revealed that average bead size of 100–250 µm of the photocatalyst with ZnO stayed in the hexagonal phase, dispersed, and embedded into CS. The adsorption and photocatalyst activity of the hybrid catalyst was investigated regarding the composition of the catalyst, catalyst dosage, pH of the solution, and concentration of the solution. The catalyst with a composition of 2:1 (ZnO/CS) demonstrates the optimum decolarization properties. Catalytic performances were recorded at up to 89% photodecolarization at pH 12 with 10 ppm of methylene blue under visible irradiation. This has brought a new approach for a highly efficient, stable, sustainable, and low-cost dye water treatment technology. • Functionalization of chitosan as support material with ZnO provides a promising stability with efficient filtration process. • Good interfacial and homogenous distribution, re-engineered the band gap energy of photocatalyst system. • Chitosan hydrophilic groups increase the absorption and trapping site the photocatalyst system.