The Kinetic Study Of Photocatalytic Degradation Of Bromophenol Blue Dye On Ag-Cdo/Polyaniline Nanocomposite Under Visible Light Irradiatio

Abstract

The integrated heterogeneous nano-scale photo-catalysts tend to be one of the most promising technologies and a good wastewater treatment strategy among the various semiconductor photo-catalysts, as they use direct solar energy and produce no secondary pollutants. The photocatalyts such as CdO NPs, Ag-CdO NPs, and Ag-CdO/PANI Nanocomposite were prepared by sol-gel method in order to investigate the degradation performance on bromophenol blue dye. Analysis of crystal structure, functional groups, morphological structure, energy band gap, and degradation efficiency of as-synthesized photocatalyts were characterized using XRD, FTIR, SEM and UV-Visible spectrophotometer respectively. Accordingly, SEM result depicts that the surface morphology of Nanocomposite seems to be composed of agglomerated micron-scaled grains with smaller size as compared to CdO NPs and Ag-CdO NPs. The FT-IR spectrum at 558, 857 and1023 cm−1 shows the absorption peak corresponds to CdO NPs, Ag-O in Ag doped CdO NPs and C-N plane deformation in PANI; strongly confirmed that Ag CdO NPs were successfully modified with PANI. The XRD patterns ascribed the several sharp and highly intensitive diffraction peaks confirm the presence of cubic CdO and Ag CdO NPs structure with decreasing crystalline size from 40.56 nm and 36.58 nm while further decreased to 8.29 nm after Nanocomposite formation. Furthermore, the effects of initial dye concentration, catalyst load, pH of solution and irradiation time were investigated. Among the photocatalyts, Ag-CdO/PANI Nanocomposite exhibited the most effective degradation efficiency of 97.30 % at pH 6, 10 ppm concentration of dye, 0.140 g of catalyst and 210 min irradiation time. Moreover, the kinetics of Photocatalytic degradation of model dye at optimized conditions followed pseudo-second -order reaction with rate constant (kapp) of 8.56x10-2 M-1 min−1 . Hence, with these developed optimum degradation conditions, it is expected that researchers could apply for the treatment of wastewater samples containing acidic organic dyes