Abstract
This study describes the direct deposition of extremely dense TiO(2) nanorods (NRs) on an ITO substrate for the improved detection of heavy metal ions (HMIs). A facile hydrothermal method was employed to synthesize TiO(2) NRs on the ITO substrate at ~130 °C. Synthesized TiO(2) NRs were analyzed for morphological, structural, and electrochemical properties. As an electrode material, TiO(2) NRs were used for the simultaneous detection of three HMIs (i.e., Cr(3+), Cu(2+), and Hg(2+)), which showed a remarkably high sensitivity of ~92.2 µA.mM(-1).cm(-2) for the Cu(2+) ion. Relatively low sensitivities of ~15.6 µA.mM(-1).cm(-2) and ~19.67 µA.mM(-1).cm(-2) were recorded for the Cr(3+) and Hg(2+) ions, respectively. The fabricated TiO(2) NR-based HMI sensor showed an effective dynamic linear detection range with low LOD values of ~21.7 mM, 37 mM, and ~ 28.5 mM for Cr(3+), Cu(2+), and Hg(2+), respectively. The TiO(2) NR-based HMI sensor exhibited efficient charge transfer over the electrode toward the trace detection of Cr(3+), Cu(2+), and Hg(2+). Moreover, the reliability of the TiO(2) NR-based HMI sensor was assessed, which exhibited a promising stability of 30 days. The obtained results indicate that TiO(2) NRs grown on an ITO substrate are a promising electrode material for detecting hazardous Cr(3+), Cu(2+), and Hg(2+) and might eventually be commercialized in the near future.