Excellent catalytic activity of Pt nanoparticles supported on defective TiO2/graphite for hydrogen evolution reaction

Exploring effective electrocatalysts based on noble metal for hydrogen evolution reaction (HER) is an attractive topic in the renewable energy field. Herein, the Pt–based nanocomposites, called Pt@TiO2–VO/C, were successfully fabricated by using a photochemical reduction method. The layered Ti3C2Tx–MXene powders were used as precursor to prepare TiO2 nanotube/C nanocomposites. The Pt nanoparticles (Pt NPs) with the diameter of 2 nm were anchored on the defective TiO2 nanotubes (TiO2 NTs). The Pt@TiO2–VO/C electrocatalysts demonstrate superior performance for HER in an acid electrolyte, with overpotentials as low as 47 and 86 mV at the current densities of 10 and 100 mA cm−2, respectively. The intrinsic HER activity with respect to electrochemical surface area of Pt@TiO2–VO/C is superior than Pt/C. The Pt@TiO2–VO/C catalysts also exhibit excellent durability. Density functional theory calculations were performed to investigate the electronic structure and HER activity of TiO2–VO supported Pt cluster. The excellent performance of Pt@TiO2–VO/C is primarily due to the strong interactions between Pt NPs and defective TiO2 NTs, known as strong metal–support interactions (SMSIs). The presence of Ti3+ ions and oxygen vacancies in TiO2 NTs facilitates the charge transfer from TiO2 NTs to Pt NPs, thereby regulating the band filling of Pt NPs. Our work provides a promising pathway to build nanocomposite catalysts constructed by MXene–derived transition–metal oxides and precious metals.