Enhanced Electrocatalytic Stability of Platinum Nanoparticles Supported on Sulfur-Doped Carbon using in-situ Solution Plasma

The metal-air battery is a form of renewable energy generation technology that produces energy electrochemically and can address energy concerns in the near future. However, state-of-the-art Pt electrocatalysts often suffer from agglomeration or detachment from carbon supports under prolonged operation, eventually limiting the long-term utilization of metal-air batteries. In this work, Pt nanoparticles were deposited on sulfur-doped nanocarbon to increase its stability. We first synthesized sulfur-doped (S-doped) and pristine carbon as support materials via a plasma process, and thereafter loaded platinum (Pt) nanoparticles onto the S-doped and pristine carbon matrix. From a sintering test at 600 °C, the Pt nanoparticles supported on pristine carbon increased from 2.4 to 5.2 nm; meanwhile, the average size of Pt NPs supported on S-doped carbon only increased from 2.2 to 2.51 nm. From the electrochemical analyses, the mass activity of Pt on pristine and S-doped carbon supports decreased by 25% and 10%, respectively, after 1500 cycles. The results proposed that the sulfide C–S–C bond provided a strong platinum-S-doped carbon support interaction between the support materials and the loaded Pt nanoparticles. Thus, S-doped carbon supports can serve as a stabilizer of Pt nanoparticles to enhance their durability in the application of metal-air batteries and other electrochemical devices.