TiO_2/cyclized polyacrylonitrile hybridized nanocomposite: An efficient visible-light photocatalyst prepared by a facile 'in situ' approach

摘要

TiO_2/cyclized polyacrylonitrile (CPAN) hybridized nanocomposites (h-TCP) were obtained via an "in situ" method. TiO_2 sol-gel was prepared initially in the presence of polyacrylonitrile (PAN). Then the prepared TiO_2/PAN gel was heat-treated for simultaneous crystallization of TiO_2 and cyclization of PAN to obtain h-TCP nanocomposites. The as-prepared nanocomposites were characterized and compared with TiO_2 nanoparticles surface-modified by CPAN (sm-TCP) and neat TiO_2. Results show that CPAN molecular chains existing around TiO_2 nanocrystals play a good role in partition to TiO_2 nanocrystals, which decreases the mean size of TiO_2 crystals in h-TCP, alleviates the aggregation of h-TCP nanocomposites, and increases their specific surface areas. The electron-hole pair separation efficiency and interface charge transfer efficiency are also improved compared with neat TiO_2 and sm-TCP. The h-TCP nanocomposites possess excellent visible-light photocatalytic activity and stability for photodegradation of methyl orange and phenol. The visible-light photocatalytic mechanism of h-TCP has been discussed.