Nitrogen-doped carbon is considered one of the most promising oxygen reduction catalysts due to its low cost and high activity, however, it still falls short of Pt/C. In this study, we report a strategy for the preparation of highly reactive N-doped hierarchical porous carbon by primary pyrolysis using zinc acetate as a stand-alone zinc source and amino-rich reactants as carbon and nitrogen sources to introduce Zn-N structures into mesoporous structures generated by the hard template method using the strong coordination of zinc and amino groups. Benefited from the simultaneous optimization of the hierarchical porous structure and nitrogen-doping, the half-wave potential of Zn(OAc) -DCD/HPC is as high as 0.909 V vs. RHE, much better than that of commercial Pt/C catalysts (0.872 V vs. RHE). In addition, zinc-air batteries assembled with Zn(OAc) -DCD/HPC (P =198 mW cm ) as the cathode exhibit higher peak power density compared to Pt/C (P =168 mW cm ). This strategy might open up new opportunities for designing and developing highly active metal-free catalysts.
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http://dx.doi.org/10.1002/cplu.202300238 | DOI Listing |
Carbohydr Polym
March 2025
State Key Laboratory of Featured Metal Materials and Life-cycle Safety for Composite Structures, School of Resources, Environment and Materials, Guangxi University, Nanning 530004, China; State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute, Sichuan University, Chengdu 610065, China. Electronic address:
High-performance green functional materials have garnered significant interest for electromagnetic interference (EMI) shielding applications, but creating customized, low-density, high-strength and high-efficiency biomass-based shielding materials remains challenging. In this study, lightweight Ca doped sodium alginate (SA) porous scaffolds with a carbon nanotube (CNT)/graphene (Gr) hybrid conductive network were fabricated via direct ink writing (DIW) 3D printing. The SA/CNT/Gr inks with unique rheological properties were formulated and architectures with arbitrarily customized structures could be freely constructed based on the printable inks.
View Article and Find Full Text PDFJ Phys Chem Lett
January 2025
Department of Physics, Indian Institute of Technology Delhi (IITD), Delhi 110016, India.
The oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are considered to be the most important processes in metal-air batteries and regenerative fuel cell devices. Metal-organic polymers are attracting interest as promising precursors of advanced metal/carbon electrocatalysts because of their hierarchical porous structure along with the integrated metal-carbon framework. We developed carbon-coated CNTs with Ni/Fe and Cu/Fe as active sites.
View Article and Find Full Text PDFAdv Mater
January 2025
Max Planck Institute for Solid State Research, Heisenbergstr. 1, 70569, Stuttgart, Germany.
The rapid advancement of covalent organic frameworks (COFs) in recent years has firmly established them as a new class of molecularly precise and highly tuneable porous materials. However, compared to other porous materials, such as zeolites and metal-organic frameworks, the successful integration of hierarchical porosity into COFs remains largely unexplored. The challenge lies in identifying appropriate synthetic methods to introduce secondary pores without compromising the intrinsic structural porosity of COFs.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
National Energy Metal Resources and New Materials Key Laboratory, Engineering Research Center of the Ministry of Education for Advanced Battery Materials, Hunan Provincial Key Laboratory of Nonferrous Value-Added Metallurgy, School of Metallurgy and Environment, Central South University, Changsha 410083, P. R. China.
Rechargeable Zn-air batteries (RZABs) are poised for industrial application, yet they require low-cost, high-performance catalysts that efficiently facilitate both the oxygen reduction reaction (ORR) and the oxygen evolution reaction (OER). The pivotal challenge lies in designing multimetal active sites and optimizing the carbon skeleton structure to modulate catalyst activity. In this study, we introduce a novel hierarchical porous carbon-supported FeCoNi bifunctional catalyst, synthesized via a spray combustion method.
View Article and Find Full Text PDFChemistry
January 2025
Yangzhou University, School of Chemistry and Chemical Engineering, CHINA.
Designing transition metal oxide (TMO)/porous carbon composite materials for the oxygen reduction reaction (ORR) is a promising strategy in high-performance fuel cell technology. In this study, we used the isolation effect and pore-creating properties of Zn2+ to fabricate a composite material comprising ultrasmall Fe3O4 particles anchored on hierarchically N-doped porous carbon nanospheres. This material, referred to as CPZ1.
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