Document Type

Article

Publication Date

7-22-2025

Department

Department of Materials Science and Engineering

Abstract

A novel single-step low-temperature pyrolysis method is developed to efficiently remove encapsulated Ni nanoparticles (NPs, 10–50 nm) from both regular-grade (< 5 wt.% metal impurities) and industrial-grade (< 10 wt.% metal impurities) carbon nanotubes (CNTs). This approach eliminates the need for conventional multi-step purification processes, which often involve high-temperature corrosive gas oxidation and acid washing. The new strategy transforms and redistributes encapsulated Ni-NPs into homogeneously sized nanoclusters (NCs, ≈1 nm) that are evenly dispersed on the surface of CNTs. Surface and bulk sensitive spectroscopic analyses reveal the predominant formation of Ni3N-NCs, along with some metallic Ni-NCs. The treated materials demonstrate exceptional electroactivity toward CO2 reduction to CO, with the best-performing CNT-PTFE-Mel-650 sample achieving an ultra-low onset overpotential of −19 mV and 98% CO selectivity in a current density range of 100–700 mA cm−2. This NC catalyst demonstrates 25% lower voltage at 700 mA cm−2 compared to the single atom catalyst (SAC) control. Experimentally verified ab initio molecular dynamics (AIMD) models are simulated, and subsequent density functional theory (DFT) calculations further support the thermodynamic stability of Ni3N-NCs and their favorability for CO2 reduction. This work establishes a new method for creating ligand-free electroactive NCs for efficient electrochemical reactions.

Publisher's Statement

© 2025 The Author(s). Advanced Functional Materials published by Wiley-VCH GmbH. Publisher’s version of record: https://doi.org/10.1002/adfm.202503439

Publication Title

Advanced Functional Materials

Creative Commons License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

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