Double-heterojunction structure of SbxSn1-xO2/TiO2/CdSe for efficient decomposition of gaseous 2-propanol under visible-light irradiation

作者：Rawal Sher Bahadur^*; Chakraborty Ashok Kumar; Kim Yong Joo; Kim Hark Jin; Lee Wan In

来源：RSC Advances, 2012, 2(2): 622-630.

DOI：10.1039/c1ra00551k

Highly crystallized antimony-doped tin oxide (ATO; SbxSn1-xO2, x = 0.1) of similar to 50 nm size was prepared by co-precipitation of SnCl4 center dot 5H(2)O and SbCl3, followed by heat-treatment at 1000 degrees C. The prepared ATO nanoparticles of deep blue color revealed a profound light-absorption in the visible range. ATO/TiO2 composites were prepared by covering the surface of ATO nanoparticles with TiO2 using the sol-gel method. Under visible-light irradiation (lambda %26gt;= 420 nm), the prepared ATO/TiO2 showed a notable photocatalytic efficiency in decomposing gaseous 2-propanol (IP), which seemed to be caused by the hole-transfer mechanism between the valence bands (VB) of ATO and TiO2, since the ATO%26apos;s VB level is located lower than that of TiO2. Subsequently, a double-heterojunction ATO/TiO2/CdSe structure was prepared by loading CdSe quantum dots (QDs) onto the surface of the ATO/TiO2, which dramatically enhanced the visible-light photocatalytic efficiency. In fact, the catalytic activity of ATO/TiO2/CdSe in evolving CO2 from IP, was similar to 3 times that of ATO/TiO2 and twice that of typical N-doped TiO2. The unexpectedly high efficiency of ATO/TiO2/CdSe seemingly is due to the unique band matching among these semiconductors. With sensitization of ATO and CdSe, not only the holes but also the electrons are generated in the VB and CB, respectively, of TiO2 under visible-light irradiation.

• 出版日期2012