One pot synthesis and performance of N- and (Mg,B,N)-doped ZnO for photocatalytic and antibacterial applications: Experimental and theoretical investigations

Abstract

Nowadays, environmental problems are increasingly varied and the development of various diseases. Due to its ability to create defect in band gap energy and strong antibacterial activity against a variety of microorganisms, ZnO is used to solve both issues. However, ZnO has a large band gap energy, so it is necessary to decrease band gap by doping. In this study, the synthesis of ZnO and ZnO doped materials (N- and (Mg,B,N)-doped ZnO) through the solid-state was carried out. The phases of doped ZnOs are hexagonal wurtzite, according to the results of the characterization using XRD, Raman spectroscopy, and HR-TEM. Surface morphology for N-doped ZnO does not form agglomeration, while in (Mg,B,N)-doped ZnO, agglomeration occurs due to the difference in charge of B with Zn. The existence of dopant in ZnO lattice was confirmed by EDS and XPS. (Mg,B,N)-doped ZnO has the highest specific surface area (14.388 m2/g) according to the BET analysis. The formation of peaks in 358 nm, 520 nm, and 650 nm during PL examination indicates a reduction in the rate of electron-hole recombination and defects. The recombination rate was confirmed by EIS Nyquist spectra result. The band gap energy owing to doping decreased from 3.13 eV to 3.10 eV and 3.12 eV for N- and (Mg,B,N)-doped ZnO, respectively. The lifetime of undoped ZnO, N-doped ZnO, and (Mg,B,N)-doped ZnO is 0.526, 0.610, and 0.695 ns, respectively. Photocatalyst test results showed that N-doped ZnO and (Mg,B,N)-doped ZnO materials were optimum for degradation of methyl violet for under visible light with degradation efficiency of 89.28 % and 93.24 %, respectively. N-doped ZnO and (Mg,B,N)-doped ZnO produce inhibition zone of 7.18 mm and 14.15 mm for Escherichia coli bacteria and 7.50 mm and 11.80 mm for Staphylococcus aureus bacteria. Additionally, molecular docking studies were used to explain a potential mechanism for in vitro bacterial activity.