Mineralization of flexible mesoporous TiO2 photoanodes using two low temperature dielectric barrier discharges in ambient air
| Authors | |
|---|---|
| Year of publication | 2019 |
| Type | Article in Periodical |
| Magazine / Source | Contributions to plasma physics |
| MU Faculty or unit | |
| Citation | |
| Web | https://onlinelibrary.wiley.com/doi/full/10.1002/ctpp.201700213 |
| Doi | http://dx.doi.org/10.1002/ctpp.201700213 |
| Keywords | dielectric barrier discharge (DBD); homogeneity of the treated surface; low-temperature plasma; mesoporous photoanodes; plasma mineralization |
| Description | Two types of dielectric barrier discharges (DBDs), volume DBD (called Industrial Corona) and coplanar DBD, were used for low temperature (70 degrees C) atmospheric pressure plasma mineralization of mesoporous methyl-silica/titanium dioxide nanocomposite photoanodes. The photoanodes with a thickness of approx. 300 nm were inkjet-printed on flexible polyethylene terephthalate (PET) foils. Plasma treatments of both DBDs led to changes in the chemical stoichiometry and morphology of the mesoporous photoanodes, resulting in a significant increase of the work function from approx. 4.0 to 4.3 eV and 4.8 eV, after plasma mineralization with volume DBD and coplanar DBD, respectively. We also studied the effect of plasma mineralization on the photoelectrochemical properties of the flexible mesoporous TiO2 photoanodes. Plasma mineralization with volume DBD and coplanar DBD showed different effects on the generated photocurrent in the photoanodes. Although the plasma mineralization with volume DBD showed only a minor effect on the photocurrent, plasma mineralization with coplanar DBD led to significantly higher photocurrents. We found that the enhancement of the photoelectrochemical properties was related to the homogeneity of the plasma-treated surfaces-arising from different spatial properties of the plasma between volume and coplanar DBDs. Furthermore, the results showed that plasma mineralization using coplanar DBD can effectively change the energy levels of the surface. This resulted in the enhancement of the work function and the photoelectrochemical properties of the mesoporous TiO2 photoanodes. This contribution shows that coplanar arrangement of electrodes in DBDs generates plasma of higher efficacy compared with standard volume DBD that is currently often used in industrial processes. |
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