Highly Dense TiO2 Nanorods as Potential Electrode Material for Electrochemical Detection of Multiple Heavy Metal Ions in Aqueous Medium

This study describes the direct deposition of extremely dense TiO2 nanorods (NRs) on an ITO substrate for the improved detection of heavy metal ions (HMIs). A facile hydrothermal method was employed to synthesize TiO2 NRs on the ITO substrate at similar to 130 degrees C. Synthesized TiO2 NRs were analyzed for morphological, structural, and electrochemical properties. As an electrode material, TiO2 NRs were used for the simultaneous detection of three HMIs (i.e., Cr3+, Cu2+, and Hg2+), which showed a remarkably high sensitivity of similar to 92.2 mu A.mM(-1).cm(-2) for the Cu2+ ion. Relatively low sensitivities of similar to 15.6 mu A.mM(-1).cm(-2) and similar to 19.67 mu A.mM(-1).cm(-2) were recorded for the Cr3+ and Hg2+ ions, respectively. The fabricated TiO2 NR-based HMI sensor showed an effective dynamic linear detection range with low LOD values of similar to 21.7 mM, 37 mM, and similar to 28.5 mM for Cr3+, Cu2+, and Hg2+, respectively. The TiO2 NR-based HMI sensor exhibited efficient charge transfer over the electrode toward the trace detection of Cr3+, Cu2+, and Hg2+. Moreover, the reliability of the TiO2 NR-based HMI sensor was assessed, which exhibited a promising stability of 30 days. The obtained results indicate that TiO2 NRs grown on an ITO substrate are a promising electrode material for detecting hazardous Cr3+, Cu2+, and Hg2+ and might eventually be commercialized in the near future.