Facile solvothermal synthesis of ultrafine platinum nanowires on carbon nanotubes to enhance hydrogen evolution performance

Ultrafine platinum nanowires have drawn considerable attention due to their promising applications in electrocatalytic fields. Despite the numerous reports on Pt nanostructures, the one-pot synthesis of ultrafine Pt nanowires on conductive substrate still remains challenge. Herein, we demonstrate the facile solvothermal synthesis of ultrafine Pt nanowires with an average diameter of 1.4 nm and an average length of 16.8 nm in-situ assembled on muti-walled carbon nanotubes. The surface properties of MWCNT, solvent composition, and reductants determine the final morphology of Pt NWs. The Pt NWs/CNT prepared under optimal synthesis conditions are demonstrated to be a potential electrocatalyst for acidic HER, exhibiting only 64 mV overpotential at 100 mA/cm 2 in 0.5 M H 2 SO 4 . The mass activity of 15.2 A/mg Pt at an overpotential of 70 mV and the exchange current density of 0.53 mA/cm 2 Pt are 2.2 and 1.3 times higher than that of commercial Pt/C, respectively. DFT calculations reveal the planar-sites on Pt nanowires exhibit appropriate H adsorption free energy, and the abundant edge-sites of ultrafine structure ensure optimal H adsorption behavior at high coverage, thus contributing to the excellent HER performance of Pt NWs.