Electrochemical synthesis of Ni nanoparticles over tailored TiN thin film electrodes for glucose sensing

Abstract

In this work, conductive ceramic electrodes instead of conventionally metal electrodes were used to synthesize metallic nanoparticles by electrochemical deposition. Ni nanoparticles/TiN thin film-coated electrodes were selected as a model system for the synthesis in glucose sensing applications. TiN that is conductive and exhibits much better chemical stability than metal was applied as the electrode. Size and coverage control of the nanoparticles was feasibly achieved by tailoring surface morphologies of the TiN thin films electrodes. Here, TiN with two types of surface morphologies were employed for the investigation, including nano granular (G-TiN) and nano pyramidal (P-TiN) structures. Under the same electrodeposition conditions, the growth of Ni nanoparticles was substantially faster on the G-TiN electrodes than that over the P-TiN electrodes. This is probably due to the steric effect that confines the growth of nanoparticles over the pyramidal-shaped P-TiN, leading to smaller nanoparticles. The smoother surface of G-TiN allows the growth of nanoparticles more freely, yielding larger nanoparticles. The coverage of the nanoparticles could also be modulated on the two types of TiN electrodes. For glucose sensing, not only the size but the coverage of the nanoparticles affects significantly the sensitivities of glucose sensing. The highest sensitivity of about 1350 μA mM−1 cm−2 was obtained by optimizing the size and coverage of the Ni nanoparticles on the TiN electrodes. The Ni nanoparticles/TiN thin film-coated electrode system has great potential for glucose sensing applications.