A Hybrid of the FeN-Fe Heterojunction Supported on N-Doped Carbon Nanobelts and Ketjen Black Carbon as a Robust High-Performance Electrocatalyst.

Herein, an extremely simple l-alanine-assisted pyrolysis method was proposed for the construction of a novel hierarchically porous hybrid of FeN-Fe supported on N-doped carbon nanobelts and Ketjen black carbon (denoted as FeN-Fe@N-C/N-KB). It has been found that the participation of l-alanine in pyrolysis can dramatically increase the total pyridinic-N/graphitic-N content in FeN-Fe@N-C/N-KB, which is peculiarly conducive to the enhancement of ORR performance. The in-site formation of the FeN-Fe heterojunction via the thermal reduction and decomposition of FeN as well as the introduction of cheap KB can significantly improve the ORR performance.

Self-Supported Hierarchical IrO@NiO Nanoflake Arrays as an Efficient and Durable Catalyst for Electrochemical Oxygen Evolution.

Although traditional IrO nanoparticles loaded on a carbon support (IrO@C) have been taken as a benchmark catalyst for the oxygen evolution reaction (OER), their catalytic efficiency, operation stability, and IrO utilization are far from satisfactory due to the inferior powdery structure and inevitable corrosion of both IrO and C under the oxidizing potentials. Here, a rational design of a self-supported hierarchical nanocomposite, composed of IrO@NiO nanoparticle-built porous nanoflake arrays vertically growing on nickel foam, is proposed, which is demonstrated as a versatile strategy to achieve improved OER activity, remarkable long-term stability, and significantly reduced loading of IrO (0.62 atom %).