Engineering of SnO2/TiO2 heterojunction compact interface with efficient charge transfer pathway for photocatalytic hydrogen evolution

Abstract

Fabricating an efficient charge transfer pathway at the compact interface between two kinds of semiconductors is an important strategy for designing hydrogen production heterojunction photocatalysts. In this work, we prepared a compact, stable and oxygen vacancy-rich photocatalyst (SnO2/TiO2 heterostructure) via a simple and reasonable in-situ synthesis method. Briefly, SnCl2–2H2O is hydrolyzed on the TiO2 precursor. After the pyrolysis process, SnO2 nanoparticles (5 nm) were dispersed on the surface of ultrathin TiO2 nanosheets uniformly. Herein, the heterojunction system can offer abundant oxygen vacancies, which can act as active sites for catalytic reactions. Meanwhile, the interfacial contact of SnO2/TiO2 grading semiconductor oxide is uniform and tight, which can promote the separation and migration of photogenerated carriers. As shown in the experimental results, the hydrogen production rate of SnO2/TiO2 is 16.7 mmol h−1 g−1 (4.4 times higher than that of TiO2), which is owing to its good dynamical properties. This work demonstrates an efficient strategy of tight combining SnO2/TiO2 with abundant oxygen vacancies to improve catalytic efficiency.