Carbon quantum dots/hydrogenated TiO2 nanobelt heterostructures and their broad spectrum photocatalytic properties under UV, visible, and near-infrared irradiation

To make the best and highest use of solar light is the main direction and object of photocatalysis and water-splitting. Although UV and visible active photocatalysts have been extensively investigated, the use of near-infrared (NIR) wave band of solar light remains a nearly blank area. Here we report the UV-visible-NIR broad spectrum active photocatalytic property of CQDs/hydrogenated TiO2 (H-TiO2) nanobelt heterostructures. The improved UV and visible photocatalytic property can be attributed to improved optical absorption, charge carrier trapping, and hindering of the photogenerated electron-hole recombination of oxygen vacancies and Ti3+ ions in TiO2 nanobelts created by hydrogenation. The NIR photocatalytic activity is from photo-induced electron transfer, electron reservoir, and up-converted PL properties of CQDs, which can absorb NIR light and convert into visible light and transfer to visible photocatalytic active H-TiO2 nanobelts. This work offers a simple strategy for the fabrication of a wide spectrum of active heterostructured photocatalysts by assembling CQDs on the surface of UV-visible photocatalysts, which opens a door for photodegradation, photocatalytic water splitting, and enhanced solar cells using sunlight as light source. (C) 2014 Elsevier Ltd. All rights reserved.