Electrospinning derivative fabrication of sandwich-structured CNF/Co3S4/MoS2 as self-supported electrodes to accelerate electron transport in HER

Abstract

The substitution of noble metal catalysts with earth abundant TMs as electrocatalysts for hydrogen production is of great significance. One biggest bottleneck for high-efficiency water electrolysis in TM catalysts is the sluggish reaction kinetics or electron transport efficiency. The electrical coupling between the substrate and the catalytic material can accelerate the electron transport, enhancing the charge transfer kinetics, and thereby improve the catalytic performance of the catalyst. Herein, we report a sandwich-structured CNF/Co 3 S 4 /MoS 2 , MoS 2 grown in-situ on N-doped nanofibers with Co 3 S 4 nanoparticles via electrospinning, carbonization and hydrothermal process, as self-supported electrodes for hydrogen evolution reaction. The sandwich structure is comprised of CNFs/Co 3 S 4 /MoS 2 as substrate/accelerator/catalyst. Thereinto, the three-dimensional CNF framework, intrinsically doped by nitrogen, can open accessible channels for reactants and served as substrates for the in-situ growth of Co 3 S 4 and MoS 2 nanocrystals with high conductivity and massive active sites. Hence, the CNF/Co 3 S 4 /MoS 2 shows outstanding catalytical performance in water electrospinning, only 80 mV required to drive 10 mA cm −2 current density with the Tafel slope of 99.2 mV dec −1 in alkaline media. Besides, the performance can be maintained for at least 40 h with negligible decline. This experiment can provide a new idea for the design of efficient and stable self-supporting electrodes. • The sandwich-structured CNF/Co 3 S 4 /MoS 2 were synthesized via electrospinning and carbonization. • The Co 3 S 4 nanoparticles accelerated the transfer of electrons from the substrate to the catalyst. • The Co nanoparticles break through the blockade of the carbon layer via controlling carbonization temperature. • CNF/Co 3 S 4 /MoS 2 only need 80 mV to drive 10 mA cm −2 , and the Tafel slope was 99.2 mV dec −1 . • The structure of Co 3 S 4 nanoparticles embedded on the carbon fiber stably improve the electron transmission efficiency.