Fe3Se4 rice grains anchored on cotton-derived porous carbon network for enhanced sodium ion storage and hydrogen evolution reactions

Abstract

Transition-metal selenides have been regarded as promising anode materials for energy storage and conversion fields. However, their practical application is hindered by volume expansion, polyselenide dissolution, and sluggish kinetics. Herein, porous Fe3Se4 rice grains were successfully encapsulated on cotton derived carbon network (CN@Fe3Se4@C) by facile solvothermal method combined with in-situ selenization process. Beneficial from the unique structure, the CN@Fe3Se4@C electrode exhibits excellent sodium storage properties (302 mAh g−1 at 500 mA g−1 after 500 cycles) and hydrogen evolution reactions (HER) performance (an overpotential of 168 mV at a current density of 10 mA cm−2, and a low Tafel slope of 77 mV dec−1). Electrochemical mechanism investigations demonstrate that the carbon coated porous Fe3Se4 nanoparticles and ant nest-like carbon network can shorten the diffusion path for Na+ ions and suppress volume expansion. Meanwhile, the 3D interconnected porous carbon framework can provide multiple channels for fast electron transport and improve electron conductivity. In addition, the thin amorphous carbon layers on individual Fe3Se4 rice grains can well inhibit the shuttle effect of polysulfides and the agglomeration of Fe3Se4, ensuring fast kinetics and long-term stability. This study reveals the great potential of CN@Fe3Se4@C as active materials for sodium ion batteries and hydrogen production.