Preparation of annular TiO2 nanoparticles constructed by high-energy surfaces and enhanced visible-light photocatalytic activityElectronic supplementary information (ESI) available: Detailed characterization and DFT calculation parameters as described in the text. See DOI: 10.1039/c7nj01560g

• Main Authors: Kong, Fanxia, Xia, Yuguo, Jiao, Xiuling, Chen, Dairong
• Format: Article
• Language: English
• ISSN: 1144-0546; 1369-9261
• DOI: 10.1039/c7nj01560g

Controlling overexposed facets with high energy is pivotal for various applications, particularly catalytic reactions which occur on the surfaces of nanostructures. Herein, we report a combined solvothermal and etching method to synthesize anatase TiO 2 nanocrystals with energetic exposed facets, which exhibit enhanced visible light photodegradation activity towards RhB. Electron microscopic photographs revealed that the initially prepared nanocrystals had a hierarchical structure stacked by secondary nanoplates, and time dependent experiments proved that the formation process followed an oriented aggregation mechanism and a subsequent grain growth. In addition, quantum mechanical calculations revealed that the etching process could occur along three directions of TiO 2 nanocrystals, and the formation of Ti 3+ defects was thermodynamically favorable, which was further demonstrated by XPS spectra. The reasons for the enhanced photodegradation activity are also discussed through the production of reactive oxygen species (ROS), which revealed that the adsorption of surface hydroxyls and H 2 O may be the main reason for this enhancement. Annular TiO 2 nanoparticles were synthesized through a combined solvothermal and etching process.