One-pot synthesis of Mo2C&MoS2 loaded on N/S co-doped carbon materials as the electrocatalyts for hydrogen evolution reaction

Abstract

Biomass is a potential precursor for preparing functional carbon materials, as the organic component containing nitrogen (N), sulfur (S) would create the atomic dopants to adjust electronic properties of the carbon material. The heteroatom-doped carbon materials loaded with non-precious metal compound is considered to be a promising alternative for hydrogen evolution reaction (HER). Herein, Mo2C and MoS2 nanoparticles with a size of 5 ∼ 20 nm uniformly loaded on the N/S-co-doped carbon sheets (NSC) are prepared via direct pyrolysis of ginkgo leaves with ammonium molybdate tetrahydrate (AMT). Carbon black (CB) is used to replace ginkgo leaves to obtain Mo2C@NC3 to further study the influence of N/S-containing organic components in ginkgo leaves. By comparing with Mo2C@NC3, the XPS reflect the characteristic peak of Mo is positively shifted while the characteristic peak of N 1 s is obviously negatively shifted, indicating a stronger electron interactions of Mo2C&MoS2@NSC3. Benefited from the intense electronics transfer, the efficiency electrochemical active areas of Mo2C&MoS2@NSC3 is larger than Mo2C@NC3 (10.72 vs. 4.97 mF/cm−2), thus the Mo2C&MoS2@NSC3 gives a smaller overpotential of 209 mV to obtain the current density of 10 mA cm−2, together with a low Tafel slope value of 85.5 mV dec-1.