Efficient, durable and inexpensive electrocatalysts that accelerate sluggish oxygen reduction reaction kinetics and achieve high-performance are highly desirable. Here we develop a strategy to fabricate a catalyst comprised of single iron atomic sites supported on a nitrogen, phosphorus and sulfur co-doped hollow carbon polyhedron from a metal-organic framework@polymer composite. The polymer-based coating facilitates the construction of a hollow structure via the Kirkendall effect and electronic modulation of an active metal center by long-range interaction with sulfur and phosphorus. Benefiting from structure functionalities and electronic control of a single-atom iron active center, the catalyst shows a remarkable performance with enhanced kinetics and activity for oxygen reduction in both alkaline and acid media. Moreover, the catalyst shows promise for substitution of expensive platinum to drive the cathodic oxygen reduction reaction in zinc-air batteries and hydrogen-air fuel cells.

A new class of dual metal and N doped carbon catalysts with well‐defined porous structure derived from metal–organic frameworks (MOFs) has been developed as a high‐performance electrocatalyst for oxygen reduction reaction (ORR). Furthermore, the microbial fuel cell (MFC) device based on the as‐prepared Ni/Co and N codoped carbon as air cathode catalyst achieves a maximum power density of 4335.6 mW m−2 and excellent durability.

No abstract

No abstract

No abstract

Zn–air battery is a promising energy storage device because of its remarkably high energy density. However, development of affordable oxygen catalysts with high eletrocatalytic activity and excellent durability is of critical importance for the implementation of rechargeable Zn–air batteries. Here, we report a novel synthesis of three-dimensional (3D) Co–N–C nanowire network (NN) and its remarkable electrocatalytic performance as a bifunctional electrocatalyst in rechargeable Zn–air batteries. The carbon nanowire network was derived from cost-effective cellulose, with Co and N heteroatom doping achieved by annealing the self-assembled MOF@amine-modified cellulose under N2. As reported here, the best sample synthesized at 800 °C, referred to as 3D Co–N–C NN-800, demonstrated an oxygen reduction reaction (ORR) onset potential of 1.05 V and oxygen evolution reaction (OER) overpotential of 0.47 V (10 mA cm–2). As a result, a Zn–air battery assembled with 3D Co–N–C NN-800 demonstrates a small voltage gap of 0.8 V between charge and discharge and excellent durability, as evidenced by a minimal decay after 30 h operation (90 cycles, 15 mA cm–2). This study demonstrates a novel design strategy to enhance the electrcatalytic site and its homogeneity via the covalently bonded doping, which could be employed for the further development of bifunctional carbonaceous electrocatalysts.

On account of fossil energy depletion and environmental crisis, Zn-air battery with high energy density, eco-friendliness, and excellent safety has been considered as a promising candidate for next-generation energy devices....

Highly efficient noble metal-free bifunctional catalysts for expediting the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in metal-air batteries or fuel cells are still challenging and imperative. In this work, we report a facile and scalable method for syntheizing three-dimensional (3D) macroporous Co-embedded N-doped carbon interconnecting with in situ growth carbon nanotubes (CNTs). The as-synthesized material exhibits great electrocatalytic performance for ORR with an onset potential of 0.901 V vs RHE as well as a high limited current density of 4.83 mA/cm in an alkaline electrolyte under a rotation speed of 1600 rpm at 5 mV/s. Furthermore, this 3D porous carbon also shows good electrocatalytic performance for OER in an alkaline electrolyte. This high electrocatalytic performance is mainly attributed to its large specific surface area and highly conductive CNTs and the synergistic effect between Co-active species and the carbon framework. The result of a two-electrode Zn-air battery based on this carbon material achieves a peak density of 163 mW/cm at a voltage of 0.63 V, indicating the great potential of the catalyst for battery application.