Electrochemical Probing of H_2O_2 Using TiO_2-ZrO_2-HfO_2 Modified Glassy Carbon Electrode: A Promoted Sacrificial Behavior of Hf~(4+) ions

摘要

In recent years, there is a massive demand for the development of high-performance sensing technologies to curtail the effect of environmental pollutions. One such primary ecological concern is water pollution, where the major risk factor is associated with the concentrations of the chemical residues (hydrogen peroxide [H2O2]) in drinking water. Keeping this in view, we have demonstrated a non-enzymatic electrochemical probing of H2O2 in water employing microwave-assisted TiO2-ZrO2-HfO2 ternary nanocomposite for the first time. Structural analysis revealed the formation of monoclinic phases of ZrO2 and HfO2 along with anatase phased TiO2. Dynamic sensing characteristics of the TiO2-ZrO2-HfO2 nanocomposite were studied by varying the concentration of H2O2 from 1 to 19 mu M where the sensor showed linearity up to 9 mu M. The LOD and LOQ of the sensor were found to be 0.32 and 1.06 mu M respectively along with the sensitivity of 6.71 mu A center dot mu M-1. The dominant signal change of Zr4+ ions in the TiO2-ZrO2-HfO2 nanointerface upon interacting with H2O2 has significantly inhibited the Hf4+ ions from taking part in the redox reaction, which refers to the sacrificial behavior. The reaction hierarchy was observed as ZrO2 (E-o = - 1.23 V) TiO2 (E-o = - 1.15 V [suppressed peak]) HfO2 (no redox peaks observed sacrificial). The real-time recovery study was carried out using the tap water, field water, and urban river water samples with repeatable and reproducible characteristics. Thus, our study provokes a new dimension in exploring many ternary nanointerfaces in the near future for the electrochemical sensing of different analytes.