Dissymmetric interface design of SnO2/TiO2 side-by-side bi-component nanofibers as photoanodes for dye sensitized solar cells: Facilitated electron transport and enhanced carrier separation

• Published in: Journal of colloid and interface science Vol. 583; pp. 24 - 32
• Main Authors: Wei, Kun, Gu, Xiu Yun, Chen, En Zi, Wang, You Qing, Dai, Zhe, Zhu, Zi Ran, Kang, Shi Qiang, Wang, Ao Chen, Gao, Xiu Ping, Sun, Geng Zhi, Pan, Xiao Jun, Zhou, Jin Yuan, Xie, Er Qing
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.02.2021
• Subjects: Dye-sensitized solar cells; Heterojunction interface; Needleless electrospinning technique; Side-by-side bi-component nanofibers (SBNFs); Tin dioxide; Titanium dioxide; Side-by-side bi-component nanofibers (SBNFs); Tin dioxide; Dye-sensitized solar cells; Heterojunction interface; Needleless electrospinning technique; Titanium dioxide
• ISSN: 0021-9797; 1095-7103
• DOI: 10.1016/j.jcis.2020.09.017

[Display omitted] •Dissymmetric SnO2/TiO2 SBNFs were designed with a V-channel electrospinning method.•The diameter of small SnO2 NFs can be well tube between 20 and 80 nm.•The DSSCs based on SnO2/TiO2 SBNFs show the maximum PCE of 8.3%. SnO2/TiO2 type II heterojunctions are often introduced to enhance the separation efficiency of photogenerated carriers in photoelectrochemical electrodes, while most of these heterojunctions are of core–shell structure, which often limits the synergistic effect from the two components. In this work, dissymmetric SnO2/TiO2 side-by-side bi-component nanofibers (SBNFs) with tunable composition ratios have been prepared by a novel needleless electrospinning technique with two V-shape connected conductive channels (V-channel electrospinning). Results show that this V-channel electrospinning technique is more stable, controllable and tunable for the large-scale preparation of SBNF materials compared to the traditional electrospinning using two side-by-side metal needles. And these SnO2/TiO2 SBNFs are dissymmetric and comprised of a tiny SnO2 NF (tunable diameter within 20–80 nm) and a Sn-doped TiO2 NF (diameter of ~ 250 nm) with a side-by-side structure. Moreover, the dye-sensitized solar cells (DSSCs) based these dissymmetric SnO2/TiO2 SBNFs show the maximum power conversion efficiency (PCE) of 8.3%, which is 2.59 times that of the ones based on the TiO2 NFs. Series of analyses indicate that the enhancements in PCE could mainly be due to the improved electron transport via SnO2 NFs and the enhanced carrier separation via dissymmetric SnO2/TiO2 heterojunction interface. This research will give some new insight in the preparation of SBNFs for high-performance photoelectrochemical devices.