Nitrogen Doped Reduced Graphene Oxide Based Pt–TiO₂ Nanocomposites for Enhanced Hydrogen Evolution

Abstract

Electrochemical hydrogen production from water is an attractive clean energy generation process that has enormous potential for sustainable development. However, noble metal catalysts are most commonly used for such electrochemical hydrogen evolution making the process cost ineffective. Thereby design of hybrid catalysts with minimal use of noble metals using a suitable support material is a prime requirement for the electrolysis of water. Herein, we demonstrate the superior hydrogen evolution reaction (HER) activity of the platinum nanoparticles (Pt NPs) supported on faceted titanium dioxide (TiO₂) nanocrystals (Pt–TiO₂) and nitrogen doped reduced graphene oxide (N-rGO) based TiO₂ nanocomposite (Pt–TiO₂–N-rGO). The ternary Pt–TiO₂–N-rGO nanocomposite exhibits a superior HER activity with a small Tafel slope (∼32 mV·dec^–1), exchange current density (∼0.22 mA·cm^–2), and excellent mass activity (∼3116 mA·mg_pt^–1) at 300 mV overpotential. These values are better/higher than that of several support materials investigated so far. The excellent HER activity of the ternary Pt–TiO₂–N-rGO nanocomposite is ascribed to the presence of Ti­(III) states and enhanced charge transportation properties of N-rGO. The present study is a step toward reliable electrochemical hydrogen production using faceted TiO₂ nanocrystals as support material