S,N dual-doped carbon nanotubes as substrate to enhance the methanol oxidation performance of NiO nanoparticles

Surface atomic engineering of substrates provides an efficient way to further improve the catalytic activity and stability of coupled catalysts for methanol oxidation. In this paper, S,N dual-doped carbon nanotubes (S,N-CNTs) with high doping levels of S (4.78 at%) and N (3.58 at%) were generated by laser irradiation, and used as substrate to in-situ load NiO nanoparticles (NPs). S and N atoms in CNTs provided abundant anchor sites for NiO NPs to restrain their growth, strengthen the interaction between NiO NPs and CNTs, and promote the interfacial electron transportation. Therefore, electrochemical tests demonstrated that NiO/S,N-CNTs shown a high primary methanol oxidation activity of 2200 mA/mg, a long-term durability with 65.8% of mass activity maintained after 40000s, and an excellent methanol saturation concentration of 13 M. This work provides a facile strategy to fabricate S,N-CNTs and helps to understand the effect of heteroatoms in carbonaceous substrates on boosting the electroactivity of coupled catalysts.