Boosting photogenerated carriers for organic pollutant degradation via in-situ constructing atom-to-atom TiO₂/ZrTiO₄ heterointerface

Constructing favorable heterointerface to facilitate photogenerated carrier transport is an effective way to improve the photocatalytic activities of semiconductor catalysts. However, the fabrication of atomic-level interface remains a challenge due to the difficulties in constructing intimate interface contact. Herein, a unique atom-to-atom TiO₂/ZrTiO₄ heterointerface with the potential formation of Ti–O–Ti(Zr) bonds between TiO₂ and ZrTiO₄ was constructed through the in-situ formation of the two components using a one-step sol-gel method. The resulting photocatalyst exhibited superior photocatalytic activity and high stability, i.e., about 97% of Rhodamine B was degraded after visible light irradiation for 90 min for three consecutive photodegradation cycles. By further analyses such as refined X-ray diffractometer (XRD), X-ray photoelectron spectrometer (XPS), Raman microscope (Raman), photoluminescence (PL), and photoelectrochemical spectra (TP and EIS), it revealed that the atom-to-atom heterointerface of TiO₂/ZrTiO₄ with stronger interaction forces would greatly accelerate the charge separation as well as provide generous defect sites, boosting the number of photogenerated carriers available at reaction sites, thus contribute to the improvement of photocatalytic performance. The present work demonstrates a new approach of in-situ construction for interface engineering TiO₂ based catalyst, providing design guidelines for heterointerface photocatalytic structures.