Matoa leaf extract mediated synthesis of Se-doped ZnO nanoparticles and their photocatalytic capability

In this work, ZnO-based powders were synthesized by a simple biosynthesis method using matoa leaf extract and microwave irradiation. The pure ZnO was modified with selenium doping (5, 10 and 15 at.%) to improve the photocatalytic capability in degrading 4-nitrophenol. The synthesized powders had wurtzite structure and XRD analysis demonstrated a change in ZnO lattice parameters with Se doping. Granular surface morphology and decrease in particle size with Se doping were observed by using FESEM. Meanwhile, EDX confirmed the presence of Zn, O and Se elements in the doped samples and BET analysis showed that the specific surface area ranged from 10 to 18 m(2)/g. The observed strong absorption in UV region decreases with Se doping from 367 to 357 nm and is accompanied by an increase in the bandgap energy from 3.14 to 3.23 eV. Under UV irradiation, the ZnO powder doped with 5 at.% Se revealed the highest degrading reaction rate of -0.0218 min(-1) and photocatalytic efficiency of 88.4% compared to other samples. Therefore, it was shown that an optimal amount of Se and simple biosynthesis route can enhance the photocatalytic capability of ZnO.