Freestanding porous carbon membrane deriving from the alginic acid/poly(ionic liquid) complex and its high-performance HER electrocatalysis

Abstract

Porous carbon materials have attracted enormous interest and are widely applied in renewable energy storage and conversion. In this work, freestanding nitrogen/sulfur co-doped porous carbon (NSPC) membranes were fabricated facilely by carbonizing the electrostatically cross-linked complexes, composed of hydrophobic poly(ionic liquid) (PIL) and alginic acid (AA). The newly-fabricated NSPC membranes can be used directly as the electrodes for the electrocatalytic hydrogen evolution reaction (HER) and supercapacitors in the absence of any binding agents/additives. Outstandingly, NSPC-9 presented a specific capacitance (C_s) as high as 969 F g⁻¹ at the current density of 0.1 A g⁻¹. Additionally, NSPC-9 also delivered excellent HER electrocatalytic performance. In particular, a current density of 10 mA cm⁻¹ could be achieved at a low overpotential of 146 mV, and a small Tafel slope of 64 mV dec⁻¹ could be presented. Benefiting from their large surface area, moderate N/S dopants and good electron/electrolyte transport ability, as well as low cost and convenient synthesis procedure, NSPCs are promising electrode materials and have great potential applications in electrocatalysis and supercapacitors.