Hydrothermal synthesis of layered perovskite Sr2Bi4Ti5O18 for efficient photocatalytic degradation of organic pollutants

With the rapid development of industry, environmental pollution is becoming more and more serious. The use of photocatalysts to degrade the pollutants could alleviate this problem. The perovskite oxides have been regarded as promising catalysts because of their excellent catalytic properties. In this study, the nanostructured perovskite Sr 2 Bi 4 Ti 5 O 18 is prepared via a hydrothermal method and employed as a photocatalyst to degrade organic pollutants. The hydrothermal temperature is found to have a significant effect on the photocatalytic activity of Sr 2 Bi 4 Ti 5 O 18 , with the sample prepared at 180 °C exhibiting the highest degradation rate of Rh B (99% within 180 min), compared to those prepared at 140 °C (57% degradation rate) and 220 °C (90% degradation rate). The use of appropriate hydrothermal temperature benefits the increase in specific surface area and carrier transport rate of Sr 2 Bi 4 Ti 5 O 18 . The superoxide radicals (·O 2 − ) and the holes (h + ) were confirmed as the main active substances by the free radical capture experiments. This work develops a new layered perovskite photocatalyst Sr 2 Bi 4 Ti 5 O 18 for environmental application.