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

A combination of high carrier density, high surface area, solution processibility, and low-cost are desired in a material for electrocatalytic applications including H2 evolution and counter electrode of a solar cell. Also, plasmonic based applications in biological systems can be derived from such material. In this regard, 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 localized surface plasmon resonance band around 700 nm. Coatings of the nanocomposite forms counter electrode for efficient (8.9 %) dye sensitized solar cells. Furthermore, the nanocomposite acts as an efficient electrocatalyst for hydrogen evolution reaction exhibiting overpotential ~ 161 mV at a current density of 10 mA/cm2