Effect of cobalt doping and sugarcane bagasse carbon on the electrocatalytic performance of MoS2 nanocomposites

Abstract

Conductivity, active sites, and structural stability significantly affect the hydrogen evolution reaction (HER) of non-noble metals catalysts (molybdenum disulfide (MoS2)). Therefore, this work proposed a cobalt (Co) doping strategy, to improve the catalytic activity of MoS2, and MoS2 cum sugarcane bagasse derived carbon conjugate (MoS2-SCBC). The designed Co-doped MoS2 (Co-MoS2) and Co-doped SCBC-MoS2 (Co-MoS2-SCBC) nanosheets can enhance the HER activity in the acid electrolyte. The results showed that Co atoms can replace Mo atoms during the doping process of MoS2 to form covalent doping for MoS2. As a carbon carrier, SCBC did not only enhance the electronic conductivity of MoS2 and stability of the mixed structure, but also they were conducive to the dispersion of MoS2, and the exposure of more edge active sites. In addition, Co-MoS2-0.67-SCBC-0.2 showed improved HER electrochemical activity, with overpotential of 62 mV and a lowest Tafel slope of 53.86 mV dec-1 at 10 mA cm−2. The Cdl value for Co-MoS2-0.67-SCBC-0.2 was about 93.36 mF cm−2. Co-MoS2-0.67-SCBC-0.2 also exhibited high stability under acidic conditions, maintained its activity in more than 2000 cyclic voltammetry scans, and had strong durability after 12 h of 10 mA cm−2 exposure. In conclusion, this work provides a Co atom doping strategy to combine biomass waste with inert MoS2 in producing low-cost and highly active non-noble metal electrocatalysts for HER.