Effect of experimental parameters on photocatalytic degradation efficiency of TiO2 nanoparticles synthesized by electrochemical method towards Rhodamine B dye solution under natural sunlight.

Abstract

In this study, ~ 40nm anatase TiO2 nanoparticles were successfully prepared by a simple electrochemical method by using succinic acid as a non-ammonia-based electrolyte solution and titanium sheets as electrodes. The effect of experimental parameters such as conductivity (2-12 mS/cm), pH of the initial solution (5-9), current applied (0.05-2 A), and reaction time (1-4h) on catalyst productivity has been investigated. The analysis shows that at an optimum conductivity of 8 mS/cm and pH 7, an increase in applied current and reaction time maximizes the productivity of TiO2 nanoparticles. The obtained catalyst was used for photocatalytic degradation of rhodamine B (RhB) under natural sunlight irradiation. The effect of experimental parameters on photocatalytic degradation has also been studied. The result displayed that degradation efficiency was enhanced by ~ 3 times in the alkaline region compared to the normal pH condition and increased with an increase in catalyst loading and decreased with the initial concentration of RhB dye. Investigation of the photocatalytic mechanism by radical trapping experiments showed that RhB photocatalytic degradation was mainly dominated by hole and superoxide radicals, whereas hydroxyl radical plays a minor role. Moreover, the catalyst reusability analysis revealed good stability and showed excellent degradation up to four consecutive cycles with nearly negligible loss of photocatalytic efficiency. Thus, the present work offers a new opportunity in terms of maximization of productivity as well as sunlight-driven photocatalytic activity of the catalyst for their industrial application.