In-situ cobalt and nitrogen doped mesoporous graphitic carbon electrocatalyst via directly pyrolyzing hyperbranched cobalt phthalocyanine for hydrogen evolution reaction

Hydrogen energy as a promising renewable and sustainable energy has attracted growing attentions in recent years, in searching of low-cost electrocatalysts with high efficiency as alternatives of non-noble metals for hydrogen evolution reaction (HER). Herein we report an in-situ cobalt and nitrogen co-doped mesoporous graphitic carbon catalysts by directly pyrolyzing hyperbranched cobalt phthalocyanine (H-CoPc), which can efficiently catalyze HER in acidic, alkaline or neutral electrolytes. With only 0.62 at% of cobalt dopants, the outstanding Co@NG-800 catalyst exhibits excellent durability and HER activities with the overpotential as low as 286 mV in acid, 290 mV in alkaline and 480mV in neutral, achieved at 10 mA cm(-2) current density. These activities indicate that the Co@NG-800 catalyst can couple with the best available oxygen-evolving catalysts in the overall water-splitting. Meanwhile, the mesoporous structure derived from H-CoPc provides more active sites than un-hyperbranched precursor. This work may provide a novel organic metal complexes and simple route in designing highly active and durable transition metal and nitride co-doped carbonaceous electrocatalysts for HER. (C) 2018 Elsevier Ltd. All rights reserved.