(479a) Influence of the Synthesis Method on Cr Leaching during the Liquid Phase Photocatalysis of Cr-TiO2

Authors: 
Inturi, S. N. R., University of Cincinnati
Suidan, M., American university of beirut
Smirniotis, P., University of Cincinnati

There has been an increasing interest in developing catalysts for visible light photocatalytic degradation of volatile organic compounds in the past decade. The Liquid Flame Spray Pyrolysis (LFSP) is a favorable technique for controlling crystal structure, particle size and its distribution. Cr modified TiO2 have shown a higher efficiency in utilizing the visible light of the solar spectrum.  In our present studies, we are analyzing the influence of synthesis method has been investigated on structure, photocatalytic degradation of VOCs and the effect of leaching of the catalyst for pH range of 3-11. For this purpose, Ti-Cr of ratio 40 nanomaterials are synthesized by using co-precipitation, sol-gel, and compared with our previously reported Cr-TiO2 synthesized by LFSP method. ICP-MS has employed to discover the concentrations of the metals leached at the different pHs. Among the various catalysts, the catalyst synthesized by LFSP Cr-TiO2 exhibit excellent photocatalytic activity compared to the nanomaterials prepared by other synthesis methods. Temperature programmed reduction (TPR) and UV–vis spectra profiles clearly indicated that only Cr6+ phase is present in the LFSP made material sol-gel and co-precipitation synthesized catalyst have Cr3+ species along with Cr6+ species. The photodegradation ability of TiO2/Cr catalyst with Ti/Cr atomic ratio of 40 was highly related to the existence of Cr6+species which strongly interacted with TiO2.The reduction peaks in Cr-doped TiO2 shifted to much lower temperatures, due to the increase in the reduction potential of titania and chromium species. The developed catalyst also demonstrated an advantage of low metal leaching during the catalytic reaction, avoiding secondary metal contamination to the treated wastewater. The photocatalytic performance, characterizations and the effect of the leaching of Cr incorporated TiO2 material synthesized by the three different methods will be presented in the presentation.