A simple and low-cost approach to fabricate TiO2-NO2 hollow spheres with excellent simulated sunlight photocatalytic activity

•TiO2-NO2 HSs were successfully fabricated by a simple and low-cost method.•Their morphology, composition, and optoelectronic property were well characterized.•TiO2-NO2 HSs exhibit considerably high activity under simulated sunlight irradiation.•High activity is attributed to hollow spherical structure and introduced -NO2 groups.

Nitryl surface functionalized TiO2 hollow spheres (TiO2-NO2 HSs) composite material was successfully fabricated by a simple sol-gel combined with solvothermal and concentrated HNO3 treatment strategy using carbon microspheres obtained from hydrothermal carbonization of waste Camellia oleifera shells as a template. The microstructure, surface property, compositional and structural information, and optical and electronic property of as-prepared TiO2-NO2 HSs were well characterized. Compare with conventional g-C3N4 and TiO2 photocatalysts, the as-prepared TiO2-NO2 HSs exhibited excellent simulated sunlight photocatalytic activity toward aqueous organic pollutants degradation and hydrogen evolution from water-splitting, which can be attributed to their unique hollow spherical microstructure and the introduction of -NO2 groups.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slide