Investigation on integration of conducting polymers with Cu doped ZnO towards photocatalytic degradation of organic dye

Conducting polymers (CPs) and their nanocomposites with 4 wt% Cu doped ZnO (CZ) were synthesized through in situ polymerization process. X-ray diffraction analysis (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX), Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), UV-vis spectroscopy (UV-vis), and photoluminescence (PL) spectroscopy analysis were used to determine the structure, morphology, and optical features of synthesized nanocomposites. Prepared sample was investigated on photocatalytic dye degradation of Methylene Blue (MB) under natural sunlight in open atmosphere. The impact of CPs (polyaniline (PANI), polypyrrole (PPy) and polythiophene (PTh) integrated CZ was investigated towards photocatalytic dye degradation of MB. PPy nanocomposites exhibit the highest photocatalytic activity when compared to other CPs nanocomposites. The addition of PPy to the CZ lowered the band gap (2.33 eV), which is advantageous for absorbing visible light. The 5 wt% PPy with respect to weight of CZ (5PCZ) polymer nano-composite exhibited best photocatalytic activity (92 % in 210 min) when compared to other synthesized samples. Catalyst showed good recyclability property even after three uses. The photocatalytic breakdown of MB was also verified by chemical oxygen demand (COD) measurement and MB degradation by products was investigated by using liquid chromatography-mass spectrometry (LC-MS). This research may leads to develop a sustainable environmental water purification technique.