Photocatalytic Synthesis of Ultrafine Pt Electrocatalysts with High Stability Using TiO2 Decorated N-Doped Carbon as Composite Support.

Commercial Pt/C (Com. Pt/C) electrocatalysts are considered optimal for oxygen reduction hydrogen evolution reactions (ORR and HER). However, their high Pt content and poor stability restrict their large-scale application. In this study, photocatalytic synthesis was used to reduce ultrafine Pt nanoparticles in situ on a composite support of TiO2-decorated nitrogen-doped carbon (TiO2-NC). The nitrogen-doped carbon had a large surface area and electronic effects that ensured the uniform dispersion of TiO2 nanoparticles to form a highly photoactive and stable support. TiO2-NC served as a composite support that enhanced the dispersibility and stability of ultrafine Pt electrocatalyst, owing to the presence of N sites and the strong metal-support interaction. Relative to Com. Pt/C, the as-obtained Pt/TiO2-NC had positive shifts of 27 and 10 mV in the ORR half-wave potential and HER overpotential at -10 mA cm-2, respectively. After an accelerated durability test, Pt/TiO2-NC had lower losses in electrochemical specific area (0.7%) and electrocatalytic activity (0 mV shift) than Com. Pt/C (25.6%, 22 mV shift). These results indicate that the developed strategy enabled the facile synthesis and stabilisation of ultrafine Pt nanoparticles, which improved the utilisation efficiency and long-term stability of Pt-based electrocatalysts.