Reduction of crack formation in TiO2 mesoporous films prepared from binder-free nanoparticle pastes via incorporation of electrospun SiO2 or TiO2 nanofibers for dye-sensitized solar cells

TiO2 mesoporous films have attracted growing interests for many energy conversion and storage applications. During preparation of the TiO2 films from binder-free nanoparticle pastes, the formation of cracks is a challenging issue. Herein, we report two facile methods to prepare TiO2 mesoporous films from a binder-free TiO2 nanoparticle paste with significantly reduced crack formation via incorporation of either thin electrospun SiO2 nanofibrous mat or short electrospun TiO2 nanofibers. The reduction of crack formation (i.e., the improvement of film integrity) of the binder-free TiO2 mesoporous films was investigated by optical microscopy and scanning electron microscopy. Thereafter, these films were studied as photoanodes in quasi-solid-state dye-sensitized solar cells; and the assembled devices exhibited energy conversion efficiencies of 4.5% with stable performances over long storage time. (C) 2015 Elsevier Ltd. All rights reserved.