Morphology-engineering of ultrathin In₂S₃/mesoporous TiO₂ heterojunctions via precursor-directed synthesis for efficient photocatalysis

Synthesis of nanostructured materials with unique composition, size and morphology plays a crucial role in designing high-efficient photocatalysts. In this work, a novel precursor-directed synthetic route is developed to construct ultrathin In2S3/mesoporous TiO2 heterojunction by in situ decorating TiO2 on the surface of ultrathin In2S3 nanoflakes. The solid-state titanium alkoxide is an important precursor, which can be converted directly to porous TiO2 for increasing the specific surface area of TiO2. Meanwhile, the ultrathin In2S3 nanoflakes are in situ constructed via precursor-directed synthetic process with the thickness less than 3nm, which can supply numerous specific surface areas and a large number of active sites for the nucleation of TiO2 during the hydrothermal synthesis and result in the uniformly dispersed TiO2 nanoparticles. The results confirm that the constructed In2S3/TiO2 heterojunction possesses high specific surface area up to 139.72 m(2)/g. More importantly, the employment of unique synthetic method together with heterostructure design not only broaden the light absorption of catalyst to visible light region but also create tight interface bonding between In2S3 and TiO2 to achieve higher efficiency in charge transfer and separation. Thus, the obtained catalysts exhibit outstanding photoactivity for methyl orange (MO) degradation with visible light irradiation. This current work presents a simple and effective avenue for constructing naonomaterials with morphology control, which may be promising for rational design of solar conversion and storage devices.