ABSTRACT
This paper reports a general electrospinning method to prepare various metal phosphide/carbon nanofibers composite for electrochemical hydrogen evolution reaction (HER) catalysts. An earth-abundant organic acid-phytic acid is successfully incorporated into a conventional electrospinning precursor as the phosphorus source, and continuous nanofibers can be obtained through spinning. After heat treatment, metal phosphide/carbon composite nanofibers can be obtained, with fine phosphide nanoparticles well dispersed on the surface of an interconnected carbon backbone network. Such fibrous structures offer fast charge transfer pathways and enlarged active surface area, which are beneficial for electrocatalysts. As a result, enhance HER catalytic activity can be achieved.
ABSTRACT
Fabrication of highly reactive and cost-effective electrode materials is a key to efficient functioning of green energy technologies. Decorating redox-active metal sulfides with conductive dopants is one of the most effective approaches to enhance electric conductivity and consequently boost capacitive properties. Herein, hierarchically hollow Ag2S-NiCo2S4 architectures are designed with an enhanced conductivity by a simple solvothermal approach. With the favorable porous characteristics and composition, the optimized Ag2S-NiCo2S4-5 electrode exhibits higher specific capacitance (276.5 mAh g-1 at a current density of 1 A g-1), a good rate performance (56.3% capacity retention at 50 A g-1), and an improved cycling stability (92.4% retention after 2000 cycles). This finding originates from the enhanced charge transportation ability within the hierarchical structure, abundant electroactive sites, and low contact resistance. In addition, a battery supercapacitor device constructed with the Ag2S-NiCo2S4-5 as a positive electrode displays a maximum energy density of 63.3Wh kg-1 at an energy density of 821.8 W kg-1 with an excellent cycling stability (89.4% capacity retention after 10 000 cycles). Therefore, the present work puts forward new possibility to develop composite electrodes for energy storage battery-supercapacitor.