Gold-Nanoparticle-Decorated Titanium Nitride Electrodes Prepared by Glancing-Angle Deposition for Sensing Applications

Abstract

Titanium nitride (TiN) and gold (Au)-decorated TiN nanorod array electrodes were fabricated on Au substrates using glancing-angle deposition (GLAD), and the electrochemical properties of these materials were investigated in potassium chloride and buffered solutions containing potassium ferricyanide, ascorbic acid, uric acid, and dopamine. Cross-sectional scanning electron microscopy images depict an array of vertical nanocolumns that are ∼30 nm in width and ∼300 nm in height with sharp pointed apexes. The atomic percent ratio of N to Ti is 40:60, as revealed by X-ray photoelectron spectroscopy. Decoration of the GLAD-produced TiN nanorods with Au nanoparticles reduces the width between nanocolumns from ∼23 to ∼15 nm and improves the electroactivity of the electrodes. The capacitive current in potassium chloride increases by a factor of 2, and the electron-transfer rate of potassium ferricyanide increased by 4. The addition of Au nanoparticles to the TiN nanorod support also significantly improves the elec...