Figure 2.

(a) Schematic of the green sol-gel synthesis of ZnO NPs. (b) Chemical mechanism of the ZnO NPs’ formation. As synthesized and annealed ZnO samples at temperatures of 300–900 °C. (c) X-ray diffraction pattern. (d) FTIR Plot. (e) Thermogravimetric spectra. Figure adapted with permission from Reference [36]. Copyright 2020 RSC.