Effect of ion doping on catalytic activity of MWCNT-polyaniline counter electrodes in dye-sensitized solar cells

•Multi-walled carbon nanotubes-polyaniline composites doped with metal ions were synthesized for dye-sensitized solar cells.•Ions doping influences the catalytic activities of the multi-walled carbon nanotubes-polyaniline composites strongly.•The dye-sensitized solar cells using this kind of counter electrode gave an efficiency of 6.0%.

Multi-walled carbon nanotubes (MWCNT)-polyaniline (PANI) composite electrodes doped with transition metal ions of Ni2 +, Mn2 +, Co2 +, and Cu2 + are fabricated for use as counter electrode (CE) in dye-sensitized solar cells (DSSCs). The cyclic voltammetry and electrochemical impedance spectroscopy results reveal that the catalytic activities of the MWCNT-PANI electrodes are strongly affected by the ion doping. Ni2 + and Co2 + can improve the catalytic activities of the MWCNT-PANI remarkably, while doping with Cu2 + shows an opposite effect. Mn2 + doping showed no effect on the catalytic activity of the composite electrode. The DSSCs containing MWCNT-PANI CEs doped with Ni2 + and Co2 + show power conversion efficiencies of 6.00 and 5.75%, much higher than the efficiency of DSSCs using the pristine MWCNT-PANI CE (4.58%).

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