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

Nitryl surface functionalized TiO 2 hollow spheres (TiO 2 -NO 2 HSs) composite material was successfully fabricated by a simple sol-gel combined with solvothermal and concentrated HNO 3 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 TiO 2 -NO 2 HSs were well characterized. Compare with conventional g-C 3 N 4 and TiO 2 photocatalysts , the as-prepared TiO 2 -NO 2 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 -NO 2 groups.