Large-scale and green preparation of multifunctional ZnO

Abstract

Highly active and multifunctional zinc oxide (ZnO) was synthesized using the water bath method. The concentrated NaOH solution rapidly converted zinc ions to ZnO. The solvent was then recycled multiple times after separating from the ZnO product, and the crude sodium sulfate by-product was precipitated through crystallization at room temperature. The entire recycling process produces no pollutant emissions and yields an average of 86.13 % zinc, achieving a green and efficient synthesis of ZnO. Xenon (Xe) radiation increases oxygen vacancies in ZnO, enhancing gas sensing. The sample S3 of ZnO sensors was obtained by xenon lamp irradiation for 9 h showing a 2.4 times higher response to 100 ppm NO2 at 90 ℃ (653.12) compared to the sample S0 of ZnO sensors without xenon lamp irradiation. Moreover, ZnO has excellent UV absorption in the wavelength range of 290–380 nm. By impregnating cotton fabrics with ZnO materials, the UV protection factor (UPF) of cotton textiles was increased from 4 to 33.