Surface modified ZnO nano structures: Electrochemical studies for energy applications and removal of emerging organic pollutant dye by photo induced hetero-catalysis

Surface modified Cu-ZnO nanostructures with different ratios of Cu (0.0 %, 2.5 %, 5.0 %, 7.5 % and 10.0 %) have been fabricated using a simplified sol gel auto combustion method (SGAC). The utilization of aqueous methanolic solution (50:50 ratio) as the reaction medium, with zinc chloride, ZnCl2, serving as a precursor to modified Cu-ZnO nanostructures and ZnO nanostructures (NSs) in particular, was a novel aspect of this study. XRD, FTIR, SEM, EDX, and UV-Visible spectrum analyses were carried out for the analysis of products. The prepared ma-terials were used to study the electrochemical and photocatalytic properties. By introducing Cu metal on the surface of ZnO, the electrical conductivity was increased, and this attribute was investigated using energy band gap calculations and CV analysis. The energy band gap of fabricated nanostructures found to be decreased from 3.36 to 3.20 eV. The Cu modified ZnO based electrode showed the enhanced relative electron transport and increased peak current which made it to be more efficient in electrochemical applications. Degradation study of Tartrazine azo dye (organic) was carried out to examine the photo-induced catalytic activities of prepared materials under solar radiations, UV-light and darkness. The photocatalytic activity was revealed to be optimum up to 86.12 % when exposed to solar radiations and also with increasing Cu concentration up to 10.0 % on the ZnO surface. When compared to pure ZnO, all synthesized Cu modified ZnO NSs exhibited increased peak current, enhanced relative electron transport and optimized photo-induced catalytic degradation of organic pollutant dye. It was revealed that products manufactured using the SGAC technique had higher quality and produced better results for the intended applications than those previously reported.