Enhanced photocatalytic degradation of Metanil Yellow dye using polypyrrole-based copper oxide–zinc oxide nanocomposites under visible light

Metanil Yellow, an azo dye used as an adulterant that contaminates the environment along with a majority of nature’s freshwater resources. Polymer matrix nanocomposites can be one of the best in purifying Metanil Yellow from polluted water. Our knowledge of the polymer matrix nanocomposite in degrading dyes remains limited despite its importance. Here we used two samples: copper oxide–zinc oxide nanocomposite (CZ) and polypyrrole-based copper oxide–zinc oxide nanocomposite (PpCZ). The average crystallite size obtained from XRD analysis is 23 nm and 27 nm for CZ and PpCZ respectively. Thermogravimetric analysis showcased the heat stability and temperature response of the samples. Microstructural studies such as SEM and TEM used to visualize the aggregation and shape of the nanocomposites. UV–visible spectroscopy studies helped in calculating the direct optical bandgaps, and FTIR spectroscopy explained the molecular vibrations of the samples. This unbiased study revealed that more than 90% of the degradation was achieved using polypyrrole-based copper oxide–zinc oxide nanocomposite by photocatalytic studies. Our findings showed that using polypyrrole-based copper oxide–zinc oxide nanocomposites over copper oxide–zinc oxide nanocomposites increases the degradation percent by more than 50% and can be more efficient and economical in the longer run. Graphical abstract