Colloidal Nanocomposite of TiN and N-Doped Few-Layer Graphene for Plasmonics and Electrocatalysis

Abstract

A combination of high carrier density, high surface area, solution processability, and low cost is desired in a material for electrocatalytic applications, including H2 evolution and a counter electrode of a solar cell. Also, plasmonic-based applications in biological systems can be derived from such material. In this regard, a colloidal nanocomposite of TiN and N-doped few-layer graphene (TiN-NFG) is synthesized from molecular precursors. TiN nanocrystals (NCs) provide free electrons for electrical conductivity and plasmonics, whereas NFG is responsible for charge transport, high surface area, and colloidal stability. Colloidal TiN-NFG nanocomposites exhibit a localized surface plasmon resonance band at around 700 nm. Coatings of the nanocomposite form a counter electrode for efficient (8.9%) dye-sensitized solar cells. Furthermore, the nanocomposite acts as an efficient electrocatalyst for hydrogen evolution reaction, exhibiting an overpotential ?161 mV at a current density of 10 mA/cm2.