Sol-gel synthesis of Ba-doped ZnO nanoparticles with enhanced photocatalytic activity in degrading Rhodamine B under UV-A irradiation

In this work, Ba-doped ZnO (Ba/ZnO) nanoparticles were synthesized through a facile sol-gel approach without the use of surfactants. The impacts of Ba content and calcination temperature on the performance of Ba/ZnO nanoparticles as photocatalyst in degrading Rhodamine B (RhB) under UV-A light irradiation were investigated. The results of the study indicated performance of Ba/ZnO nanoparticles than bare ZnO nanoparticles. Maximum photocatalytic activity was achieved at 0.1% Ba doped ZnO at 400 °C calcination temperature. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Energy Dispersive X-ray Spectroscopy (EDX), nitrogen physisorption and Diffuse Reflectance Spectroscopy (DRS) techniques were used for investigating the structure and properties of Ba/ZnO nanoparticles. XRD pattern did not indicate any peaks regarding Ba phase in Ba/ZnO nanoparticles and a wurtzite crystal structure was observed. Also, mapping analysis revealed fair Ba distribution in ZnO lattice. Near spherical shape was observed in SEM image for Ba/ZnO nanoparticles and results of BET and BJH analysis indicated specific surface area of 109.81 m2 g−1 and pore volume of 0.424 cm3 g−1. DRS spectra indicated decrease in band-gap energy for 0.1% Ba doped ZnO in comparison with bare ZnO.