Porous Carbon Nanoflakes Doped with Boron Derived from Carbon Fabric Containing Polyester as Efficient Electrocatalysts for Green Hydrogen Production

Developing Pt-free electrocatalysts is the main solution for reducing the intolerable cost of hydrogen production through the hydrogen evolution reaction (HER), while sustaining rare-earth elements. Thus, we have synthesized carbon nanoflakes derived from carbon cloth doped with controllable boron atoms (Bx/C), where x refers to boron atomic contents (x = 3.42, 5.04, 9.79, and 14.64 wt.%), driven by the impregnation of carbon cloth containing polyester (CC) in an aqueous solution of boric acid, followed by drying at 80 °C for 1 h and then calcination at 500 °C for 2 h under nitrogen. The method allows the conversion of one-dimensional CC to a two-dimensional flake-like structure, in situ enriched with B-C motifs as active sites for HER. The HER performance depends on interfacial interaction of boron with carbon, but B1/C (B = 3.42 wt %) was the optimum with a HER current of 370 mA/cm2 at −0.78 V, overpotential at 10 mA/cm2 (ƞHER@10) of 372 mV, Tafel slope of 166 mV/dec, and stability for 60 h, besides a hydrogen production rate of 1.57 mol·g−1·h−1 of catalyst, due to endowing surface area, intermolecular charge transfer, and electrical conductivity. The data obtained may pave the way for designing heteroatom-integrated carbon from biomass for promoting low-cost HER.