Ingenious design and construction of Ti3+-TiO2/C nanofibers with significantly enhanced photocatalytic H2 evolution

Abstract

Herein, the Ti3+-TiO2/C hybrid with fluffy mesh structure is successfully synthesized through carbothermal reduction method using the white sponge scarfskin of shaddock peel (denoted as SSP) as template and carbon source. During the preparation process, the SSP not only can contribute to building the fluffy mesh structure, but also can offer carbon source for reducing Ti4+ to Ti3+ in the Ti3+-TiO2/C composite. Furthermore, under argon atmosphere, the Ti3+ content in the composite can be adjusted via changing the calcining temperature of the tube furnace. In comparison with that of the individual TiO2, the resultant Ti3+-TiO2/C hybrids both exhibit superior photocatalytic H2 production property under visible light or simulated sunlight irradiation. In particular, the optimized hybrid of Ti3+-TC-350–600 exhibits excellent catalytic performance. The H2 production rates of it are 2341 and 6695 μmol g-1h−1 under visible light and simulated sunlight irradiation, respectively. The corresponding H2 evolution rate of the Ti3+-TC-350–600 is 5.5 or 2.2 times than that of the TiO2-350–600. According to the results of the hybrid composition and microstructure, optical and electrical property, H2 production performance and differential charge density, the Ti3+-TiO2/C hybrid exhibits favorable H2 production performance should be ascribed to the synergistic effect of the Ti3+, graphite-like carbon and fluffy mesh structure. Therefore, this study could offer a valuable thinking and reference for design and synthesis the Ti3+-TiO2/C photocatalyst for H2 evolution.