Widening of the electroactivity potential range by composite formation - capacitive properties of TiO2/BiVO4/PEDOT:PSS electrodes in contact with an aqueous electrolyte.

Konrad Trzciński,Mariusz Szkoda,Marcin Łapiński,Andrzej P Nowak,Anna Lisowska-Oleksiak

doi:10.3762/bjnano.10.49

Konrad Trzciński, Mariusz Szkoda + Show 3 more

Open Access

https://doi.org/10.3762/bjnano.10.49

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Abstract

Composites based on the titania nanotubes were tested in aqueous electrolyte as a potential electrode material for energy storage devices. The nanotubular morphology of TiO2 was obtained by Ti anodization. TiO2 nanotubes were covered by a thin layer of bismuth vanadate using pulsed laser deposition. The formation of the TiO2/BiVO4 junction leads to enhancement of pseudocapacitance in the cathodic potential range. The third component, the conjugated polymer PEDOT:PSS, was electrodeposited from an electrolyte containing the monomer EDOT and NaPSS as a source of counter ions. Each stage of modification and deposition affected the overall capacitance and allowed for an expansion of the potential range of electroactivity. Multiple charge/discharge cycles were performed to characterize the electrochemical stability of the inorganic–organic hybrid electrode. Capacitance values higher than 10 mF·cm−2 were maintained even after 10000 galvanostatic cycles (ic = ia = 0.5 mA·cm−2).

Highlights

Energy-storage technologies and sustainable energy production are currently important challenges
This report is devoted to the design and investigation of a novel electrode material, Ti/TiO2/BiVO4/PEDOT:PSS, which is characterized by a high capacity during polarization in contact with an aqueous electrolyte
pulsed laser deposition (PLD) was used for BiVO4 deposition on TiO2 with preservation of nanotubular morphology

Summary

Introduction

Energy-storage technologies and sustainable energy production are currently important challenges. Hydrogenation pretreatment was necessary to obtain PEDOT:PSS films directly on the Ti/TiO2/BiVO4 electrodes from the aqueous electrolyte. XPS analysis was performed in order to examine the influence of the hydrogenation process on TiO2 and BiVO4 electrode materials. Here the XPS high-resolution Ti 2p spectrum of the Ti/TiO2:H/BiVO4:H sample shows that after the hydrogenation process titanium exists in the Ti4+ form (Figure 3a).

Results

Conclusion