Tailored aluminum coordination in metakaolin: A defect-engineering strategy for high-performance tribocatalysis

IF 5.3 2区地球科学 Q2 CHEMISTRY, PHYSICAL

Applied Clay Science Pub Date : 2025-07-01 DOI:10.1016/j.clay.2025.107921

Kai Wang , Zhu Shu , Yuchen Wen , Jun Zhou , Xinlong Wu , Jiahui Liu , Xiaoxin Yang

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引用次数: 0

Abstract

Contact electrification, the charge exchange phenomenon occurring upon contact between dissimilar materials, is ubiquitous yet often underappreciated. Tribocatalysis, which harnesses this process to convert mechanical energy into chemical energy for degrading wastewater pollutants, has recently gained attention for its potential. In this study, we transformed natural kaolin into amorphous metakaolin (MK) tribocatalysts via a single-step calcination process, optimizing their performance through structural modulation. Solid-state NMR spectroscopy and degradation experiments revealed that MK-800, enriched with unsaturated Al[IV] and Al[V] sites, achieved a degradation rate constant of 0.1607 h⁻¹—64 times higher than that of raw kaolin. Density functional theory calculations confirmed that unsaturated aluminum coordination enhances electron mobility and reduces electron escape energy. We further refined tribocatalytic efficiency by optimizing parameters such as friction area, solution environment, and atmospheric conditions. Electron paramagnetic resonance spectroscopy identified positive charges (q⁺), hydroxyl radicals (OH), and superoxide anions (O₂⁻) as key reactive species driving pollutant degradation. This work introduces a novel, cost-effective approach to pollutant remediation and lays a theoretical foundation for advancing structural control in tribocatalysis.

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偏高岭土中定制铝配位：高性能摩擦催化的缺陷工程策略

接触通电，即不同材料接触时发生的电荷交换现象，是普遍存在的，但往往不被重视。摩擦催化，利用这一过程将机械能转化为化学能来降解废水污染物，最近因其潜力而受到关注。在本研究中，我们通过一步煅烧工艺将天然高岭土转化为无定形偏高岭土（MK）摩擦催化剂，并通过结构调节优化其性能。固体核磁共振光谱和降解实验表明，富含不饱和Al[IV]和Al[V]位点的MK-800的降解速率常数为0.1607 h−1-64倍，高于原料高岭土。密度泛函理论计算证实，不饱和铝配位提高了电子迁移率，降低了电子逸出能。我们通过优化摩擦面积、溶液环境和大气条件等参数进一步提高了摩擦催化效率。电子顺磁共振波谱鉴定出正电荷（q+）、羟基自由基（OH）和超氧阴离子（O2−）是驱动污染物降解的关键反应物质。本工作介绍了一种新的、经济有效的污染物修复方法，为推进摩擦催化的结构控制奠定了理论基础。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Applied Clay Science 地学-矿物学

CiteScore

10.30

自引率

10.70%

发文量

289

审稿时长

39 days

期刊介绍： Applied Clay Science aims to be an international journal attracting high quality scientific papers on clays and clay minerals, including research papers, reviews, and technical notes. The journal covers typical subjects of Fundamental and Applied Clay Science such as: • Synthesis and purification • Structural, crystallographic and mineralogical properties of clays and clay minerals • Thermal properties of clays and clay minerals • Physico-chemical properties including i) surface and interface properties; ii) thermodynamic properties; iii) mechanical properties • Interaction with water, with polar and apolar molecules • Colloidal properties and rheology • Adsorption, Intercalation, Ionic exchange • Genesis and deposits of clay minerals • Geology and geochemistry of clays • Modification of clays and clay minerals properties by thermal and physical treatments • Modification by chemical treatments with organic and inorganic molecules(organoclays, pillared clays) • Modification by biological microorganisms. etc...