One-pot hydrothermal synthesis of Al-doped MoS2@graphene aerogel nanocomposite electrocatalysts for enhanced hydrogen evolution reaction

Abstract

Molybdenum disulfide (MoS2) has shown its promising performance for use as an electrocatalyst for hydrogen evolution reaction (HER). However, it has commonly suffered from limited edge active sites and stagnant conductivity in this regard. Therefore in the present work, with integrating graphene aerogel (GA) supporting and Al ions doping, we report for the first time one-pot hydrothermal synthesis of Al-doped MoS2@GA aerogel electrocatalysts with 3D porous network architecture. Vertical MoS2 ultrathin nanosheets with defect-rich structure are grown on graphene nanosheets at the optimum weight ratio of 5 wt% GA, leading to the enhancement of HER activity. Simultaneously Al doping of 0.77 at% further optimizes the number of exposed active sites and conductivity. The overpotential at a current of 10 mA·cm−2 was successfully reduced to 212 mV with a Tafel slope value down to 41 mV/dec, benefiting from synergistically structural and electronic modulating of MoS2. The study thus sheds light on designing and developing high-performance 3D network electrocatalysts for HER reaction. Keywords: Vertical MoS2, Graphene aerogel, 3D network, Hydrothermal synthesis, Current density, Hydrogen evolution