Development and characterization of electrochemical sensors based on carbon modified with TiO2 nanoparticles

The aim of this study is the development and characterization of a carbon-based electrochemical sensor, modified with TiO2 nanoparticles for potential application in electroanalytical techniques. The influence of binder and modifier contents on morphological, physicochemical and electrochemical characteristics of the electrode material was investigated in order to determine the optimal ratio of the carbon material/binder/modifier. Carbon pastes were prepared from mixtures containing graphite powder, TiO2 nanoparticles and liquid hydrocarbons. Scanning electron microscopy showed that the electrode material becomes more compact with the addition and the increase in the binder material content, while increasing the proportion of TiO2 nanoparticles did not have any significant effect on the material morphology showing fairly homogeneous nanoparticle distribution in the graphite electrode material. The test results indicate that the modified carbon paste with 40 vol.% paraffin oil (PO) and 6-8 wt.% TiO2 nanoparticles is characterized by the lowest value of specific resistance. By applying cyclic voltammetry, the most pronounced degree of reversibility was obtained in relation to the standard reversible redox system ([Fe (CN)]-3/-4) for the electrode material with 30-40 vol.% PO and 8-10 wt.% TiO2 nanoparticles. Characterization of the electrode material based on carbon modified with TiO2 nanoparticles indicated that the optimal composition contains 40 vol.% PO and 6-8 wt.% TiO2 nanoparticles, which is important for application in electroanalytical techniques.