The design and fabrication of low-cost catalysts for highly efficient oxygen reduction are of paramount importance for various renewable energy-related technologies, such as fuel cells and metal–air batteries. Herein, we report the synthesis of Fe₃N nanoparticle-encapsulated N-doped carbon nanotubes on the surface of a flexible biomass-derived carbon cloth (Fe₃N@CNTs/CC) via a simple one-step carbonization process. Taking advantage of its unique structure, Fe₃N@CNTs/CC was employed as a self-standing electrocatalyst for oxygen reduction reaction (ORR) and possessed high activity as well as excellent long-term stability and methanol resistance in alkaline media. Remarkably, Fe₃N@CNT/CC can directly play the role of both a gas diffusion layer and an electrocatalytic cathode in a zinc–air battery without additional means of catalyst loading, and it displays higher open-circuit voltage, power density, and specific capacity in comparison with a commercial Pt/C catalyst. This work is anticipated to inspire the design of cost-effective, easily prepared, and high-performance air electrodes for advanced electrochemical applications.

Zn-doped MnCO₃/carbon sphere (Zn-doped MnCO₃/CS) composites were synthesized using a simple hydrothermal procedure. Among various samples (ZM-50, ZM-05, and ZMC-0), the ternary Zn-doped MnCO₃/CS (ZMC-2) catalyst demonstrated excellent visible light-induced photocatalytic activity. This improvement comes from the Zn addition and the conductive CS, which facilitate electron movement and charge transport. The catalyst exhibited efficient degradation of methylene blue (MB) over a wide pH range, achieving a removal efficiency of 99.6% under visible light. Radical trapping experiments suggested that •OH and •O₂⁻ played essential roles in the mechanism of organic pollutant degradation. Moreover, the catalyst maintained good degradation performance after five cycles. This study offers valuable perspectives into the fabrication of carbon-based composites with promising photocatalytic activity.

The design and fabrication of low-cost catalysts for highly efficient oxygen reduction is of paramount importance for various renewable energy-related technologies, such as fuel cells and metal-air batteries. Herein, we report the in situ growth of Fe3N nanoparticles encapsulated N-doped carbon nanotubes on the surface of flexible biomass-derived carbon cloth (Fe3N@CNTs/CC) via a simple one-step carbonization process. Taking advantage of its unique structure, Fe3N@CNTs/CC was employed as a self-standing electrocatalyst for oxygen reduction reaction (ORR) and possessed high activity as well as excellent long-term stability and methanol resistance in alkaline media. Remarkably, Fe3N@CNT/CC can directly play the role of both gas diffusion layer and electrocatalytic cathode in a zinc-air battery without additional means of catalyst loading, and display higher open circuit voltage, power density, and specific capacity in comparison with the commercial Pt/C catalyst. This work is anticipated to inspire the design of cost-effective, easy-preparation, and high-performance air electrodes for advanced electrochemical applications.