Zicong Zhang,Xiangli Ru,Xiaoli Yang,Zhengyu Bai,Lin Yang
In addition to C, H and O, some biomass is also rich in mineral elements. The recovery and utilization of special mineral elements is of great significance to prepare functional materials and alleviate the current energy shortage. Herein, we describe a facile strategy for making full use of the chemical composition (C, Fe) and special structure of red blood cells (RBCs) from waste pig blood to fabricate a dual metal (Fe, Co)-nitrogen (N)-doped porous carbon catalyst by pyrolysis of a mixture of RBCs biomass, cobaltous acetate, and melamine. The porous catalyst displays a comparable activity for oxygen reduction reaction (ORR) to that of commercial Pt/C catalyst, with a half-wave potential of 0.821 VvsRHEin alkaline media and 0.672 VvsRHEin acid electrolyte. Especially, the as-prepared catalyst shows excellent methanol tolerance and stability in both acidic and alkaline electrolytes, which is superior to commercial Pt/C catalysts. The excellent ORR activity of FeCo-N/C(RBC)can be ascribed to the porous morphology and the cooperation between metal and nitrogen species. This work provides a novel idea of exploiting the composition of renewable biomass to modulate the activity and stability of carbon-based ORR catalysts.
It's a major challenge to explore highly active and stable electrocatalysts for efficient hydrogen evolution reactions (HER) and oxygen evolution reactions (OER). In this work, we report a new hybrid electrocatalyst: iron-cobalt decorated nitrogen doped carbon/reduced graphene oxide-700 °C (Fe-Co-CN/rGO-700). The catalyst shows an excellent electrocatalytic performance toward HER and OER in alkaline solution, which has lower overpotentials of 0.215 V and 0.308 V at the current density 10 mA cm −2 , respectively, and this catalyst has an outstanding durability (after 45 h). The excellent activity mainly benefit from the highly dispersed iron/cobalt species, sheet structure with high porosity, the improvement of electronic structures with nitrogen-doped carbon and high conductivity of rGO. Combined with the density function theory (DFT) calculations, the improvement of the HER and OER performance were also attributed to the balance of adsorption/desorption of the hydrogen and oxygen-containing intermediates, and the increased electronic states density near the Fermi level. The proposed work provides a novel and simple strategy to synthesize a porous carbon electrocatalyst material using metal-organic frameworks (MOFs) as precursor with high activity and strong stability for HER and OER.