XAS studies of brain-sponge CNClZnO nanostructures using polyaniline as dual source for solar light photocatalysis

Abstract Carbon, nitrogen and chlorine triple doped zinc oxide (CNClZnO) nanostructures have been synthesized from zinc acetate dihydrate and polyaniline by in-situ thermal oxidation method. PANI acts as both a soft template and a dopant source. In this study, PANI was taken in three different weight percentages 1%, 5% and 10% and the prepared samples are named as PZnO-1, PZnO-5 and PZnO-10 respectively. X-Ray Diffraction (XRD) analysis shows the formation of pure wurtzite structure in all the samples. Synchrotron based X-Ray Absorption (XAS) studies have been done to study the doping process in ZnO. These confirm the doping of ZnO lattice with carbon, nitrogen and chlorine. The Scanning Electron Microscopy (SEM) images show the formation of porous structures with the surface resembling that of a brain sponge. The band gap of the samples keeps decreasing with increase in the PANI weight %, with the band gap reducing to 2.51 eV for PZnO-10. Finally, these prepared samples are used as photocatalysts for the degradation of methylene blue dye under direct sunlight. Among all the three doped ZnO samples, PZnO-5 showed the highest photocatalytic efficiency with the kinetics rate constant k as 0.0153 min−1.