Visible and infrared light photocatalysis of Cr(VI) by CdTe nanoparticles

The utilization of near-infrared (NIR) light may greatly enlarge the application range of irradiated light of a photocatalyst, which is still an issue needing to be solved. In this work, CdTe nanoparticles are firstly found to be endowed with the capacity to photo-reduce Cr(VI) to Cr(III) under infrared light irradiation. The CdTe nanoparticles are prepared under a facile hydrothermal condition, with diameters of approximately 22 nm, which shows high photo-reduced efficiencies to Cr(VI) of 82.44% at the irradiation of a Xe lamp (500 W, including the visible light and infrared light), and 25.54% under the irradiation of infrared light, respectively. The active species of e − , h + , and OH participate in the reduction of Cr(VI), and the photogenerated e − and OH both play a critical role in the infrared light region. This study proposes a new pathway for Cr(VI) photoreduction in wastewater under visible-NIR light irradiation which shows an application potential as a photocatalyst at the infrared light range and provides new insights for pollution reduction and environmental improvement.