| TiO2is n type semiconducter, and TiO2nanotubes (TNT) with large surface area, strong adsorption ability and high ion exchange capacity were made by hydrothermal method. CuO is p type semiconducter with narrow energy gap, which is easily to absorb visible light. The p-n type heterojunction facilitates the separation of electron-hole pairs.Toluene has been taken as a model pollutant to evaluate photocatalytic oxidation activity of the prepared p-CuO/n-TNT photocatalyst for indoor VOCs under visible light.Firstly, the TNT were prepared by hydrothermal method. The CuO-TNT with different mol ratio of Cu/Ti were prepared by Adsorption-Calcinations’method. The samples were charactered by XRD, XPS, TEM, N2adsorption-desorption tests and UV-vis-DRS. The results showed that the materials with tubular structure were fabricated, with TNT having a BET surface of92.7m2·g-1and0.1%CuO-TNT a smaller BET surface of62.4m2·g-1The pore diameter of TNT and CuO-TNT was mainly in the range from15to50nm. The XRD pattern exhibited characteristic features of Anatase TiO2. The Cu on the TNT surface mainly existed in the state of cupric ion. HRTEM pattern and Linear Sweep Voltammetry curves indicated that CuO-TiO2heterojunction structure was formed.Electrochemical properties were investigated by Amperometric i-t Curve, Linear Sweep Voltammetry curves, Tafel Plot and Mott-Schottky. The CuO/TNT with ratio of0.1%have the best visible light response.The experimental result showed that the0.1%CuO/TNT showed the best photocatalytic oxidation capacity, with removal rates being more than75%, and CO2selectivity35%under visible light for7h.The research would be useful for the technology to modify TiO2with narrow band oxide semiconductor, and for indoor VOCs purification under visible light. |
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