UV‐Initiated Synthesis of Electroactive High Surface Area Ta and Ti Mesoporous Oxides Composites with Polypyrrole Nanowires within the Pores

This paper describes the synthesis and characterization of high surface area mesoporous Ti and Ta oxides with polypyrrole nanowires in the pores. The incorporation of polymer was used to improve the electron conductivity into the channels inside these high surface area (4001000 m(2)g(-1)) materials in order to exploit surface redox sites for possible pseudocapacitive Li storage. Synthesis was achieved using catalyst-free UV-initiated polymerization of vapor-loaded pyrrole monomer. The best materials showed improved conductivity for both the Ti and Ta oxides as well as improved Li capacity (190 mAhg(-1)) relative to the pristine material (128 mAhg(-1)) and superior capacity retention (49% as compared to 22%) for the Ti composites. The retention in surface area was also 87% compared to 49% reported previously for analogous materials synthesized by catalyst-initiated methods, which only yielded Li capacities of 170 mAhg(-1), further highlighting the superiority of this new photochemical approach.