TiO2@TiOx homojunction photocatalyst: Self-doped preparation and superior photocatalytic hydrogen evolution and dye degradation

Abstract

So far, there still existed many challenges on the effective utilization of solar energy and rapid transportation of photo-generated carrier in the photocatalysis fields. The constructing structural/functional configuration of photocatalyst by combining the homojunctions with oxygen vacancies (Ov) was a good project to overcome these inherent disadvantages. Herein, the homogeneous TiO2@TiOX photocatalysts were designed and fabricated by a solid-phase thermal reduction technology using sodium borohydride as a reducing agent. The structure, morphology, chemical binding, active species and photo-electrochemical properties of the TiO2@TiOX were sufficiently investigated via various characterization techniques and indicated that the high-quality homojunction at the TiO2-TiOX interface and abundant oxygen vacancies on the surface was formed. The photocatalytic degradation and H2 production experiment showed that the constructed TiO2@TiOX exhibited more outstanding photocatalytic performances, which was 1.4 times higher and 2 times higher than that of the Raw TiO2, respectively. The photocatalytic mechanism was proposed that the synergistic effect of optical and electrical properties of TiO2@TiOX, such as narrow gap edge and significant enhancement in conductivity, greatly strengthened the photo-response, expanded the response range of spectrum, enhanced photocarriers migration and the photocatalytic activity. This work could provide new opportunity into the design of novel structures of photocatalyst for more efficient light conversion applications.