Titania-loaded cellulose-based functional hybrid nanomaterial for photocatalytic degradation of toxic aromatic dye in water

Abstract

The dispersion of Titania on cellulose nanowhiskers was achieved using titanium tetra-isopropoxide as the precursor and sulphuric acid as a peptizing agent via the low-temperature sol-gel synthesis method. The photocatalytic activity of the resultant hybrid catalyst was studied through photocatalytic removal of toxic aromatic cationic thiazine dye (methylene blue). Diverse instrumental methods used for full characterizations of pristine and prepared materials allowed correlating the type of the chemical moiety incorporated to the formation of Titania-loaded cellulose-based functional nanomaterial as well as its stability and catalytic performance. Results indicated successful synthesis of multiscale Titania (19 nm ∼1 μm) and perpetual distribution over cellulose nanowhiskers. The latter showed high photocatalytic behavior towards the degradation of methylene blue (conc. 50 ppm) dye. The degradation reached 98.5 % in 40 min at a reaction rate of 0.188 min-1 as observed and measured through UV–vis spectrophotometer. Chemical oxygen demand (COD) analysis reveals substantial mineralization of the pollutants by reducing toxicity up to 68.64 % with complete recovery of the catalyst validated by total dissolved solids (TDS) analysis of treated water. Considering the above results, a mechanism has postulated. Kinetic study showed that the degradation reaction obeys pseudo-first-order reaction kinetics with appreciable recyclability after five (05) repeated uses. The results herein open new prospects for cellulose-based functional nanomaterial for various environmental applications.