An efficient palm waste derived hierarchical porous carbon for electrocatalytic hydrogen evolution reaction

Replacing precious Pt, Ir, and Pd-metal based catalysts with cost-effective alternatives for hydrogen production via electrocatalytic hydrogen evolution reaction (HER) would benefit significantly towards clean green energy technologies. In this perspective, we demonstrate graphene-like hierarchical porous nanosheets derived from an inexpensive dry spathe-pollen waste of palm plant as an efficient HER catalyst by pursuing “energy from waste” strategy. Investigation of chemical composition and microenvironment by X-ray photoelectron spectroscopy (XPS) confirms the presence of pyridinic, pyrrolic, and graphitic nitrogen innate from N-containing organic components. The textural features with N2 sorption measurements suggests complimentary of high surface area (1297 m2 g‒1), pore volume (0.6 mL g−1), and hierarchical micro/mesoporous architecture which could strongly promote the performance in HER catalysis. Tested as a HER catalyst, the as-prepared carbon material furnish a smaller overpotential (η10) of 0.33 V vs. RHE, at 10.0 mA cm−2 along with a small Tafel slope value of 63 mV dec−1 and long-term stability under acidic medium. The hydrogen binding energy of HPNS and undoped carbon were calculated from DFT studies to support the HPNS activity. Such exquisite properties may be attributed to unique combination of high surface area, facile electrolyte percolation within hierarchical bimodal pore system, robust electrode/electrolyte interface, and N-dopant.