Co²⁺‐coordinated NH₂‐carbon Quantum Dots Hybrid Precursor for the Rational Synthesis of Co−CoO_X/Co−N−C ORR Catalyst

Abstract

For the goal of practical industrial development of fuel cells, design and synthesis of electrocatalysts for oxygen reduction reactions (ORR) with sustainable and high performance are of great significance. In this work, the coordination of NH2‐carbon quantum dots (NCQDs) with Co2+ on carbon black was reasonably achieved via one‐pot and low‐cost hydrothermal treatment for the first time. Citric acid (CA) and urea (UA) were taken as carbon and nitrogen sources for NCQDs, respectively. The coordination of Co2+ and NCQDs were well‐characterized using spectroscopic techniques such as FTIR, UV‐visible absorption and fluorescence. Carbonization of carbon black‐supported Co/NCQDs at 800 °C under N2 atmosphere endows the pyrolysis products with high catalytic activity. The Co−CoOX/Co−N−C possesses enhanced ORR performance in terms of positive onset‐potential (∼‐0.079 V vs. SCE) and half wave potential (E1/2) (∼‐0.201 V vs. SCE), high stability, as well as the accelerated reaction kinetics.

Glucose‐hexamethylenetetramine‐derived Co, N Co‐doped Carbon Nanoflowers with Encapsulated Co@Co3O4 as Efficient Bifunctional Oxygen Electrocatalyst for Zinc‐air Batteries

“…The Co 2p 3/2 of HMT-Co/G-600 can be deconvoluted into Co 3 + and Co 2 + at 779.7 and 781.4 eV, corresponding to the Co 3 O 4 . [46] Along with the Co 3 + and Co 2 + , metallic Co is detected in HMT-Co/G-700 and HMT-Co/G-800, which agrees well with the HRTEM and XRD results. The O 1s peaks at the binding energy of 529.6, 530.7, 531.3, 532.3, and 533.6 eV in Figure 4d are associated with the lattice oxygen (O lat ) in cobalt oxides, CÀ OÀ Co, oxygen vacancies, C=O, and adsorbed-O (O ad ) for HMT-Co/G-T, respectively.…”

“…In the Co 2p XPS (Figure 4c), the peaks at around 780 and 794 eV are the Co 2p 3/2 and Co 2p 1/2 doublets, respectively. The Co 2p 3/2 of HMT‐Co/G‐600 can be deconvoluted into Co 3+ and Co 2+ at 779.7 and 781.4 eV, corresponding to the Co 3 O 4 [46] . Along with the Co 3+ and Co 2+ , metallic Co is detected in HMT‐Co/G‐700 and HMT‐Co/G‐800, which agrees well with the HRTEM and XRD results.…”

Covalent organic framework‐derived Fe, Co‐nitrogen codoped carbon as a bifunctional electrocatalyst for rechargeable efficient Zn–air batteries

“…The lattice spacing of 0.15, 0.21, and 0.25 nm is indeed consistent with CoO (200), Co 2 O 3 (102), and Fe 3 O 4 (311), respectively. [31][32][33] To further confirm the distribution of the elements, corresponding HAADF-STEM and EDX mappings are performed in Figure 1g-l Fourier transform infrared (FTIR) spectrums are presented to verify the chemical bonding of FeCo@NC, obviously showing three peaks (Supporting Information S1: Figure 4). The C=C and C=N (pyridine-N) functional groups appear in the FTIR spectrum at 1434 and 1550 cm −1 suggesting the coexistence of triazine and pyridinium.…”

One-Stop Integrated Nanoagent for Bacterial Biofilm Eradication and Wound Disinfection

“…CQDs have small sizes, excellent water solubility, and solution stability . Moreover, easy surface modification and metal coordination endow CQDs with multiple enzyme-like activities, enriching the application of CQDs-based nanomaterials in the biomedical field. , For example, Wang et. al report that metal-coordinated CQDs exhibit excellent catalytic activity compared with pure CQDs .…”