Confinement of Pt NPs by hollow-porous-carbon-spheres via pore regulation with promoted activity and durability in the hydrogen evolution reaction

Abstract

Electrochemical water splitting is a promising method to generate pollution-free and sustainable hydrogen energy. However, the specific activity and durability of noble metal catalysts is the main hindrance to the hydrogen evolution reaction. Based on the continuous pore regulation of hollow porous carbon spheres (N-HPCSs) by hexadecyl trimethyl ammonium bromide, the 6.21 wt% Pt/N-HPCSs exhibited good dispersibility, according to a low overpotential of 45 mV (10 mA cm⁻²/1 M KOH). Its mass activity was 4 times that of the commercial 20 wt% Pt/C at −0.07 V (vs. RHE) potential. We analyse that the excellent activity is due to the interaction between Pt nanoparticles and N-HPCSs so that the electron density around the Pt atoms increases, which is beneficial for H₂O to obtain electrons and transform into H_ad. Meanwhile the sea urchin-like structure of N-HPCSs facilitates the desorption of H₂. Furthermore, the overpotential showed no obvious decrease in the long-term durability test, which should be attributed to the confinement of Pt nanoparticles by the well-defined pores in N-HPCSs to avoid the aggregation of Pt nanoparticles during long-term testing.