Electrochemical Sensing of Phenol in Different Water Sources by a Titanium Oxide Nanotubes/Single-Wall Carbon Nanotubes Nanocomposite-Ionic LiquidAmplified Sensor

Abstract

Phenol and its derivatives are one of the main important pollutants of water sources. Highly sensitive electrochemical sensor modified with titanium oxide nanotubes/single-wall carbon nanotubes nanocomposite and room temperature ionic liquid (1-hexyl 3-methyl imidazolium hexafluorophosphate) (TiO2/NT/SWCNTs/IL/CPE) was fabricated for the determination of phenol in well water, seawater and urban water samples.The TiO2/NT/SWCNTs nanocomposite synthesized with thermal process and characterized with FESEM and TEM methods. Ration of mediators and pH value of solution were optimized as important factors on sensor ability for phenol determination and results confirmed best condition were obtained at pH= 6.0, 15% (v:v; 1-hexyl 3-methyl imidazolium hexafluorophosphate/paraffin oil) and 6% (w:w; TiO2/NT/SWCNTs/graphite powder). In continuous, the recorded differential pulse voltammograms (DPV) confirmed that the electro-oxidation current of phenol improved about 2.9 times by TiO2/NT/SWCNTs/IL/CPE compare to CPE and the phenol oxidation potential decrease about 105 mV. Then, the interference species on the determination of phenol evaluated and reported results showed high selectivity of TiO2/NT/SWCNTs/IL/CPE forsensingphenol in water samples. DP voltammograms show wide linear dynamic ranges between 0.1 –300 μM and a good limit of detection of about 0.05 μM for sensingphenol. Finally, TiO2/NT/SWCNTs/IL/CPE is used to determinephenolin different water samples with acceptable recovery data.