Electrochemical pathway-controlled growth of tellurium nanostructures on a nonconductive substrate

Abstract

This study demonstrates that the morphology and spatial distribution of tellurium (Te) nanostructures can be precisely controlled on electrically insulating substrates (SiO₂) by systematically tuning the electrochemical reaction pathway of HTeO2+. By varying only two key parameters, the precursor concentration and applied potential, the relative contribution of each step, including the overpotential deposition, H2Te formation, and chemical reduction, was modulated. This enabled the fabrication of diverse nanostructures, including nano-dots, nano-rods, and feather-like morphologies, under different electrochemical conditions. Notably, Te formation was achieved solely via the chemical pathway on insulating SiO₂ without the need for external electron transport, providing the first unambiguous experimental validation of EC-driven formation and growth on electrically insulating substrate. This strategy successfully circumvents the limitations of conventional electroplating techniques, which are generally restricted to conductive substrates, and offers a template-free platform for the site- and shape-selective growth of Te nanostructures. These findings present a promising route toward applications in Te-based sensors, thermoelectric devices, and bio-functional nanomaterials.