Nanocomposites and nanomaterials 

Electrocatalytic and photocatalytic activity of sol-gel Pt/TiO2 and Pt/N/TiO2 films.
Linnik O.1, Ihnatiuk D.1, Smirnova N.1, Vorobets V.2, Kolbasov G.2
Šihor M.3, Kočí K.3 
1Chuiko Institute of Surface Chemistry of the NAS of Ukraine. General Naumov Str.,17, Kyiv-03680, Ukraine. E-mail: smirnatali@gmail.com
2Institute of General & Inorganic Chemistry of National Academy of Sciences of Ukraine, Acad. Palladin Str. 32/34, 03680, Kyiv, Ukraine
3Institute of Environmental Technology, VŠB -Technical University of Ostrava, 17. listopadu 15, Ostrava, Czech Republic 

	Co-doping with N and Pt has been employed to tune the electronic structure and enhance the photocatalytic activity of films based on TiO2. Herein, the different approaches of synthesis procedures of Pt/TiO2 and Pt/N/TiO2 films to obtain Pt in different oxidation states, optical, structural, surface and photoelectrochemical characterization are reported. Their activity in environmentally important processes, as namely electrocatalytic reduction of dissolved oxygen and hydrogen as well as photocatalytic decomposition of atmospheric pollutant, nitrous oxide, to nitrogen and oxygen, is tested. 
Efficiency of Pt/TiO2 and Pt/N/TiO2 electrodes in the electrocatalytic reactions depends on the dopants’ content, pretreatment conditions. The most active catalyst for both electrocatalytic reduction of oxygen and hydrogen processes is found to be nonporous Pt/TiO2 film. It is proved that an additional UV exposure of the films brings to the increased activity in electrocatalytic oxygen reduction that can be connected with platinum ions reduction with formation of metallic Pt.
Photocatalytic decomposition of N2O was performed in an annular batch reactor illuminated with an 8 W Hg lamp (λ= 254 nm). The most active catalyst for N2O decomposition process is found to be mesoporous 1%Pt/N/TiO2 film. The lower activity of non-porous 1%Pt/N/TiO2 and 1%Pt/TiO2 films can be explained by lower adsorption degree of N2O molecules leading to the lower efficiency of photocatalytic process.

Acknowledgement: The work was supported from ERDF "Institute of Environmental Technology – Excellent Research "(No. CZ.02.1.01/0.0/0.0/16_019/0000853) and by using Large Research Infrastructure ENREGAT supported by the Ministry of Education, Youth and Sports of the Czech Republic under project No. LM2018098.“