Synthesizing ZnWO4 with enhanced performance in photoelectrocatalytic inactivating marine microorganisms

Abstract ZnWO4 was synthesized by a hydrothermal method, and different molar ratios of Zn2+/WO42− were prepared in precursor solution systems (Zn2+:WO42− = 1:1, 2:1, 3:1, 4:1, 1:2, 1:3, 1:4) in the synthesis process. On the whole, the photocatalytic activity increases with excess Zn2+ and decreases when excess WO42− is in the precursor solution; the sample exhibited the best performance when Zn2+:WO42− = 3:1, with inactivation time of 7 min, which is 36% shorter than for the original sample (1:1). The CV tests showed that the OH generation ability strengthened with excess Zn2+ and weakened with abundant WO42−; according to the SEM results, long and uniform nanorods can be gained when Zn2+ is in excess in the precursor solution, and the morphology became bulky in the case of WO42−. Apart from the morphology and properties, the immanent cause is the exposed (100) high energy plane under the Zn2+-rich condition. Generally, the molar ratio of Zn2+/WO42− in the precursor solution could adjust the morphology and face exposure of products and improve the photocatalytic activity of ZnWO4. Simultaneously, photoelectrocatalytic technology can effectively separate the e−/h+ pairs, which greatly enhances the inactivation activity.