Studies on the active radicals in synthesized inverse opal photonic crystal and its effect on photocatalytic removal of organic pollutants

Abstract

Ternary inverse opal TiO2-ZrTiO4-SiO2 photonic crystal (IOPC-TZS) photocatalysts have been synthesized in-situ by a simple template method. The morphology and thickness of the inverse opal photocatalysts with photonic crystal structure were controlled and optimized in order to obtain the inverse opal structure while maintaining the crystalline phase. The photocatalytic performance among the IOPC-TZS photocatalysts of Rhodamine B removal is 27 times higher than P25, and the excellent catalytic stability is observed even after three testing cycles. Compared with previous TiO2-ZrTiO4-SiO2 (TZS) powders, the OH radicals that appear in inverse opal photonic crystal structure play an important role in the RhB degradation due to the up-shifted band structure. The formation of the TiO2-ZrTiO4 heterojunction, the slow-photon-effect and the existence of the oxygen vacancies caused by the high active surface among the IOPC structure, result in the synergistic effect of remarkably enhanced separation efficiency and improved redox capacity of the photo-induced charge carriers, which boost the photodegradation behavior to organic pollutants.