Synthesis and characterization of CMC-wrapped Nano-ZnO for photocatalytic degradation of dye under sunlight

Abstract

This research work focused on studying the fabrication of biopolymer carboxymethyl cellulose (CMC) wrapped ZnO nano-composite materials (ZnO-CMC NCs) and its applications in the photocatalytic degradation of methylene blue (MB) using under sunlight Irradiation. ZnO-CMC NCs were synthesized by using zinc acetate dihydrate as a precursor under alkaline conditions followed by the addition of capping agent CMC followed by calcination at various temperatures. The materials were characterized by FTIR, UV-Vis and powder XRD studies. The presence of CMC as a capping agent not only facilitated the nucleation and growth of (nanoparticles) NPs but also it provided stability and functionalization to the NPs. The varying calcination temperature played a significant role in influencing the size of NCs during the synthesis process. The crystallite size of ZnO-CMC NCs were found to be 19.5959 nm, 21.2518 nm, 23.5000 nm, 27.5930 nm, 34.9789 nm at 250°C, 350°C, 450°C, 550°C, and 650°C calcinations temperature respectively. It was observed that size increases slightly by increasing the calcination temperature from 250°C to 450°C. However, further increase in calcination temperature increases crystallite size significantly. The degradation of MB dye has been studies under UV-Vis spectrophotometer and it was observed that synthesized ZnO-CMC NCs were very efficient in the photocatalytic degradation of MB under natural sunlight. We believe that, these synthesized CMC-wrapped ZnO NCs will find wide range of photocatalytic applications for the treatment of organic pollutants in various dyes used in the chemical industries.