CuO nanoparticles with biostabilizers for the catalytic decolorization of bromocresol green, crystal violet, methyl red dyes based on H2O2 in aqueous medium

Abstract

Ecofriendly biopolymers such as polyethylene glycol (PEG), carboxy methyl cellulose (CMC), starch (STA) were used as the stabilizers in the preparation of CuO nanoparticles. The sizes of CuOnps were characterized using XRD, FESEM and HRTEM measurements. The as synthesized CuOnps were used as the catalysts for the decolorization and mineralization reactions of an azo functional group containing dye (methyl red, MR) and triphenyl methylene functional group containing dyes such as bromocresol green (BCG), crystal violet (CV). In order to compare the catalytic activities of biopolymer stabilized CuOnps, a synthetic polymer, poly N-vinyl pyrollidone (PVP) stabilized CuOnp was also used as the catalyst. Pseudo-first order conditions were maintained and the kinetic parameters such as overall pseudo-first order rate coefficients, time of decolorization of 50 % decomposition and TOC values were determined. The trend in the catalytic activity for the decolorization of azo and triphenyl methylene dyes among the CuO catalysts tried was PEG > CMC > STA > PVP. Keeping the catalyst constant, the trend in the degradation rate constants among the dyes was MR > CV > BCG. The CuOnps synthesized with biostabilizers produced smaller particles and were found to be catalytically efficient.