Abstract
Here we report a material beta-CD/PANI/MWCNTs prepared through oxidative free radical polymerization of aniline (C6H5NH2) monomer in the presence of beta-CD and MWCNTs. Indigenous analytical techniques like SEM, TEM, XRD, XPS, UV-vis, and FTIR were analyzed for the characterization of the material. The principle utility of the material was extrapolated towards the visible light-mediated photodegradation of crystal violet (CV) dye. The optimized values of process variables like radiation time 120 min, pH of the dye solution as pH 5, photocatalyst dose as 15 mg, and the concentration of CV as 135 mg L-1 were taken form RSM-CCD model at 298 K temperature. The desirability of the experiment was found to be D = 0.95 with q(e, exp) = 179.25 mg g(-1) (93.54%) and q(e, cal) = 184.76 mg g(-1) (95.39%) of CV degradation. The bandgap energy (Eg) of the material using Tauc's plot was found to be 3.2 eV. Benzoic acid (BA) as a trapping agent decreases the photodegradation capacity drastically suggesting the major role of center dot OH- radical as reactive oxidant (RO) for the CV degradation. The rate-determining step, as suggested by the pseudo-first-order model in heterogeneous catalysis, follows the adsorption of CV molecule on beta-CD/PANI/MWCNTs surface and thereby their dissipation through reactive OH center dot radicals. The values of first-order rate constants (K-1) having values of 0.014, 0.015, 0.016, 0.018 and 0.019 min(-1) and a t(1/2) values of 49.5, 46.2, 43.3, 38.5 and 36.5 min were calculated for 30, 60, 90, 120 and 135 mg L-1 of CV with 15 mg of photocatalyst. (c) 2020 Elsevier B.V. All rights reserved.