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

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.