SYNTHESIS, CHARACTERIZATION AND PHOTOCATALYTIC ACTIVITY OF POLYANLINE SUPPORTED Ag3PO4/ZnO/MWCNT NANOCOMPOSITE: AN EFFICIENT VISIBLE LIGHT CATALYST FOR THE DEGRADATION OF METHYLENE BLUE

Abstract

Various industries like textile, plastic, pulp, paper and leather industry produce dye-containing wastewaters that have harmful effects on the environment. For this purpose, developing a method to evaluate the pollution problem by dyes is therefore crucial. In this study, we report the synthesis, characterization and photocatalytic application of novel nanocomposite, polyaniline supported Ag3PO4/ZnO/MWCNT. Surface area, crystal structures, thermal stability, surface functional groups, band gap energy and optical properties of the as-synthesized photocatalyst and it single/binary congeners were determined using BET, XRD, TGA, FTIR, UV-Vis and PL techniques respectively. BET shows the surface area between (0.2 m2 /g -21 m2 /g) adsorbent of all the as synthesized photocatalysts. XRD results also reveal that all the catalysts are having average crystallite size in the range 20.81-56.81nm. Photocatalytic degradation activities of as synthesized nanocomposites under visible irradiation have been evaluated for a model pollutant dye methylene blue in aqueous solution and real sewage samples collected from Bahirdar Textile Industry. The effects of pH, initial dye concentration, catalyst load, PZC, scavengers were also investigated. MB was almost 86.89% degraded in the presence of Ag3PO4/ZnO/MWCNT photocatalyst, while 97.4% degradation was observed in case of PANI-Ag3PO4/ZnO/MWCNT composite. This enhancement in the photocatalytic activity of composite may be attributed to the inhibition of recombination of photogenerated charge carriers. Stability towards the photocatalytic degradation of the polyaniline supported Ag3PO4/ZnO/MWCNT was evaluated at four degradation cycles which decreases from 97.4 to 80.42% that can confirm the desired prospect of having supported nanocomoposite. Mechanism of scavenger reaction also assure the most important species in the degradation process would be super oxide radical. Degradation result suggested that supported ternary nanocomposite photocatalyst exhibited higher efficiency on the photodegradation of both Methylene blue 97.4% and real sewage sample solution 76.19%