Novel SrZrO3-Sb2O3 heterostructure with enhanced photocatalytic activity: Band engineering and charge transference mechanism

The development of efficient and stable photocatalytic materials for water splitting and degradation of organic compounds is one of the most important goals of the scientists in the area of research for energy and environmental applications. Herein, we designed through band engineering a heterostructure consisting of SrZrO3 particles dispersed on the surface of Sb2O3, as an efficient and stable catalyst for photocatalytic water splitting and the degradation of the pharmaceutical compound tetracycline under UV and UV-vis light. SrZrO3-Sb2O3 heterostructure exhibited an enhanced electron-hole separation, transference and utilization, resulting in an improved photocatalytic activity. Recyclability tests and evaluation of the effect of the irradiation source are presented. The heterostructure showed an H-2 evolution rate of 330 mu mol g(-1) h(-1) under UV light, which is more than 8 times the activity of pure SrZrO3. Under same irradiation conditions (same lamp), the heterostructure reached a 70% of degradation of tetracycline, increasing 30% the activity of SrZrO3. These results indicate that SrZrO3 is efficiently dispersed on the surface of Sb2O3 and confirm the appropriate band alignment between the semiconductors in the heterostructure, allowing an efficient transference of charges. According to this, the increased photocatalytic activity of the heterostructure SrZrO3-Sb2O3 was adjudicated to the effective charge separation and transference in the interface of the heterostructure. A mechanism of the process is proposed and discussed by photoluminescence and electrochemical measurements. (c) 2017 Elsevier B.V. All rights reserved.