University of California, Riverside
Gongde Chen is a 2nd-year PhD student of UC, Riverside. Right now he is working in Dr. Haizhou Liu's Lab on Cr(VI) reduction in different water matrices by heterogeneous photocatalysis.
Synthesis and Application of Highly Reductive TiO2 Nanocrystals to Photo-catalytically Remove Hexavalent Chromium
Hexavalent chromium, Cr (VI), naturally occurring or coming from Industrial effluent, is high toxic and carcinogenic. California regulated the Maximum Contaminant Level (MCL) for hexavalent chromium at 10 μg/L for drinking water. Concerns about Cr (VI) on human health and environment require the transform the more toxic hexavalent form of chromium to the less toxic trivalent form. In this project, TiO2 nanocrystals with high reductive power were synthesized for the first time by inexpensive thermal hydrolysis reactions and used as the catalysts for the reduction of Cr (VI) to Cr (III) under UV irradiation. Electrons coming from conduction band of TiO2 were utilized as the reductive reagent for the removal of Cr (VI). The intrinsic nanostructures of the prepared TiO2 nanocrystals can trap the photo-generated holes and effectively donate electrons for the reduction reaction. This unique feature is able to prevent the introduction of commonly used organic scavengers for holes. Fast elimination of Cr (VI) can be achieved on the time scales of seconds and high reductive capacity by the TiO2 nanocrystals was achieved. The performance of catalyst was maintained in complex water chemical matrices without interference by inorganic species and organic compounds commonly present in source water. The outcome of this study will lead to the development of a cost-effective and highly efficient chromium removal technology.