(337g) Flame Aerosol Synthesized Cr Incorporated TiO2 for Visible Light Photodegradation of Acetonitrile

Authors: 
Inturi, S. N. R., University of Cincinnati
Boningari, T., University of Cincinnati
Suidan, M., University of Cincinnati
Smirniotis, P., University of Cincinnati



The photocatalytic activity of flame aerosol made TiO2 loaded with various amounts of Cr was studied as a catalyst for both liquid and gas phase photodegradation of acetonitrile (ACN) under visible light (400–800 nm). It was found that the optimal concentrations of Crand TiO2 exist (Ti/Cr atomic ratio = 40) for the efficient oxidation of ACN in the gas phase.XRD patterns showed a decrease in the anatase phase with increase in the amount of Cr loading. Temperature programmed reduction (TPR) and UV–vis spectra profiles clearly indicated that the Cr6+ phase is dominant in the samples with the atomic ratio of Ti/Cr equal to 50, 40, and 30. The rest of the catalysts with Ti/Cr ratios of 100, 75, 20, and 10 were found to possess Cr3+ species along with Cr6+ species. Our XPS results illustrated that the relative atomic percentage value of Ti3+/Ti4+ characterized by XPS was significantly high for the Cr/TiO2 nanoparticles with Ti/Cr = 40 atomic ratio (Ti3+/Ti4+ = 1.14, 42.1%), whereas, other samples demonstrated low atomic percentage value of Ti3+/Ti4+ (Ti3+/Ti4+ = 0.18-1.05). Moreover, Cr interacts with TiO2 nanostructure in the interface of flame-made nanoparticles, bulk Cr oxide exists over the surface of TiO2 nanostructure.The photodegradation ability of TiO2/Crcatalyst with Ti/Cr atomic ratio of 40 was highly related to the existence of Cr6+species which strongly interacted with TiO2.Among all the catalysts tested, the system with Ti/Cr atomic ratio 40 demonstrated a superior catalytic performance with the rate constant of 0.812 m3g-1mol-1 under visible light irradiation.The proposed route of the catalytic activity of the above material in visible light involves the reaction of dopant level electrons withsurface Cr6+, which makes available valence band holes to performoxidation reactions.The photocatalytic performance of flame aerosol synthesized Cr incorporated TiO2 material in both liquid and gas phase will be presented in the persentataion.