Effect of low-energy ion modification of microcomposite (1-x)WO3 – xZnO ceramics on improved photocatalytic decomposition efficiency

Abstract

The main purpose of this work is to study the possibility of using ionic modification of (1-x)WO3 – xZnO microcomposite ceramics in order to elevate their photocatalytic activity, as well as enhance stability to degradation during long-term use and exposure to aggressive environments. The objects of study were (1-x)WO3 – xZnO ceramics obtained by solid-phase synthesis from tungsten and zinc oxides. Moreover, according to X-ray phase analysis data, it was found that variations in the ratio of oxide components during their mechanical activation and subsequent thermal annealing result in the formation of two-phase ceramics with different contents of the zinc tungstate phase. The results of experiments on the photocatalytic decomposition of the organic dye Rhodamine B revealed that two-phase WO3/ZnWO4 ceramics have the greatest efficiency, for which ion irradiation with fluences of 1015 ––5 × 1015 leads to a growth in the decomposition efficiency from 80 to 95 %. At the same time, the dominant effect influencing the photocatalytic decomposition efficiency growth is the change in the band gap of the ceramics, associated with the accumulation of the athermal effect of energy dissipation of incident ions on the change in electron density. The results of assessment of changes in the strength and structural parameters of (1-x)WO3 – xZnO ceramics depending on the time spent in model solutions (to simulate the effects of environments with different acidity levels) indicate a positive effect of ionic modification on enhancing stability to degradation and softening as a result of the accumulation of amorphous inclusions.