Boosting Hydrogen Evolution on MoS2/CNT Modified by Poly(sodium-p-styrene sulfonate) via Proton Concentration in Acid Solution

Engineering the surface and the electronic structure of electrocatalysts is a typical and effective strategy to enhance their catalytic performance. Herein, MoS2 grown on carbon nanotubes (MoS2/CNT) were synthesized through a hydrothermal process, then certain polyelectrolytes were absorbed onto the surface, including poly(sodium-p-styrenesulfonate) (PSS), polyacrylic acid (PAA), sodium polyacrylate (PAAS) and polyethyleneimine (PEI). The negatively charged groups of PSS could enrich the surrounding H+ in the acid electrolyte via electrostatic interaction, which greatly improved the catalytic performance of PSS-MoS2/CNT. Moreover, the introduction of carbon nanotubes not only improved the conductivity of the electrocatalyst, but also prevented the agglomeration of MoS2 nanosheets. Therefore, PSS-MoS2/CNT displayed the best hydrogen evolution reaction (HER) performance in 0.5 M H2SO4 solution. It only required 114 mV to obtain the current density of 10 mA cm(-2) with a small Tafel slope of 46.05 mV dec(-1). Different polyelectrolytes were also used to modify MoS2/CNT to verify the factors to affect the HER performance of MoS2/CNT. This strategy provides a practicable direction of the synthesis of efficient, low-cost and environmentally-friendly electrocatalysts for HER.

Automated summary

Engineering the surface and electronic structure of electrocatalysts is an effective strategy to enhance their catalytic performance. In this study, MoS2 grown on carbon nanotubes and modified with various polyelectrolytes showed improved hydrogen evolution reaction performance, with better conductivity and prevention of agglomeration of MoS2 nanosheets. This research provides a feasible direction for the synthesis of efficient, low-cost, and environmentally friendly HER electrocatalysts.