Bin Cui,Yunfeng Zhu,Chang Li,Wei Zhou,Mengran Li,Jiabao Bai,Yana Liu,Jiguang Zhang,Rui Shi,Jun Wang,Jian Yang
The development of cost-effective, highly-active, and stable oxygen reduction reaction (ORR) electrocatalysts is crucial for advancing fuel cells and metal-air batteries. Herein, we report a two-step thermal treatment strategy for successfully introducing heteroatoms and CoFe alloys onto Vulcan XC-72R to prepare efficient electrocatalysts. Among the synthesized electrocatalysts, the N, F co-doped catalyst (CoFe/NFC) demonstrates optimal ORR performance in alkaline medium. Notably, moderate heteroatom doping generates high specific surface area, large pore volumes, and optimal carbon defects, facilitating both active site accessibility and mass transport. Density functional theory calculations reveal that the N F synergistic effect enhances metal-support interaction and optimizes *OH adsorption energy. Attractively, aluminum-air batteries equipped with CoFe/NFC cathodes present outstanding performance: a peak power density of 187.9 mW/cm 2 , a large specific capacity of 586 mAh/g Al , and stable operation for 720 min at 50 mA/cm 2 . This study offers valuable insights into heteroatom doping strategies, which may facilitate the rational design of carbon-based electrocatalysts with enhanced catalytic performance.
In this work, we prepared a sensing platform by utilising the nanocomposite of Vulcan XC-72 R carbon nanoparticles and β-cyclodextrin (β-CD/VXC-72 R) to decorate glassy carbon electrode for detecting MP sensitively. For the β-CD/VXC-72 R composite, VXC-72 R possesses high electroactive area and exceptional electrical conductivity, which is conducive to the generation of interwoven carbon conductive structures. β-CD can effectually facilitate the homogeneous dispersion of VXC-72 R and also enhance the accumulate of MP at the sensing interface. Furthermore, the presence of VXC-72 R compensates for the inherent inferior conductivity of β-CD. The collaborative interaction of VXC-72 R and β-CD enabled the prepared sensor to obtain excellent MP detection properties with a low limit of detection (LOD) of 6.7 nM in MP concentration range of 0.1–10 μM. In addition, the β-CD/VXC-72 R modified glassy carbon electrode (GCE) displayed satisfactory repeatability and reproducibility.
Xiaoyang Wang,Ziqi Fu,Ziyi Luo,Weidi Liu,Jia Ding,Jianrong Zeng,Yanan Chen,Wenbin Hu
High-loading Pt/C catalysts play an important role in the fabrication of membrane electrode assemblies with thin catalytic layer, which enhance mass transport and maintain the balance of water and heat. Unfortunately, as the loading increases, the agglomeration and growth of Pt nanoparticles (NPs) occur, causing unsatisfactory performance. Here, we present an efficient method for preparing of highly dispersed and small-sized Pt/C catalysts with Pt loadings varying from 39.01 wt% to 66.48 wt% through the high-temperature shock technique. The high density and ultrafine (~2.5 nm) Pt NPs are successfully anchored onto Vulcan XC-72R carbon black without the use of additional capping agents or surfactants. The modified carbon supports enhance the affinity for Pt precursors, contributing to loading efficiencies of 95% or more, while also providing abundant sites for the nucleation and fixation of Pt NPs, thus preventing agglomeration. In the context of the hydrogen evolution reaction in acidic media, the as-synthesized high-loading Pt/C catalysts show remarkable activity and stability, outperforming the state-of-the-art commercial Pt/C. This is mainly because the combined effects of ultrasmall and uniform Pt NPs, optimized electronic structure of Pt site, superhydrophilicity and effective anchoring of Pt NPs. The polymer electrolyte membrane electrolyzer integrated with Pt60/OX72R and commercial IrO 2 reaches 1 A cm –2 at 1.77 V and operates stably for 120 hours with a negligible voltage decay. This new strategy is fast, scalable and cost-effective for large-scale production of metal-supported catalysts, especially for the high-loading ones.
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