College of Chemical and Biological Engineering, Shandong University of Science and Technology, Qingdao 266590, China.
Analysis and Testing Center, Henan Polytechnic University, Jiaozuo 454000, China; College of Chemistry and Chemical Engineering, Henan Polytechnic University, Jiaozuo 454000, China.
J Hazard Mater. 2022 Jul 5;433:128766. doi: 10.1016/j.jhazmat.2022.128766. Epub 2022 Mar 24.
Realizing the high value-added utilization of cheap minerals in environmental catalysis has important practical significance. Herein, four nano-scale minerals, namely halloysite (Hal) nanotubes, palygorskite (Pal) nanorods, and montmorillonite (Mon) and hydrotalcite (LDH) nanosheets, were selected for in-situ supporting CeO nanoparticles (NPs) by a facile one-pot hydrothermal method. Among various nanocomposites (NCs), CeO/Pal behaves the highest peroxidase-like activity, attributing to larger surface area for uniformly dispersing CeO NPs and more exposed active oxygen vacancy (O) defects. A novel off-on colorimetric strategy was constructed for detecting toxic L-penicillamine (LPA) and Cu ion with limit of detections (LODs) of 8.37 and 9.80 μM, respectively. Density functional theory (DFT) calculations show that the O defect on CeO(111) surface can catalyze the heterolytic cleavage of HO into HO and oxygen radical (•O), instead of being two hydroxyl radicals (•OH) on clean surface. It can also act as trapping site for O and HO adsorption, improving the oxygen affinity and hydrophilicity of CeO/Pal. This study provides a feasible strategy for designing mineral-based nanozymes and an insight into the possible catalytic mechanism.
实现廉价矿物在环境催化中的高附加值利用具有重要的实际意义。在此，选择了四种纳米级矿物，即埃洛石（Hal）纳米管、坡缕石（Pal）纳米棒以及蒙脱石（Mon）和水滑石（LDH）纳米片，通过简便的一锅水热法原位支撑 CeO 纳米颗粒（NPs）。在各种纳米复合材料（NCs）中，CeO/Pal 表现出最高的过氧化物酶样活性，这归因于更大的表面积以均匀分散 CeO NPs 和更多暴露的活性氧空位（O）缺陷。构建了一种新颖的基于比色的检测策略，用于检测有毒的 L-青霉素胺（LPA）和 Cu 离子，其检测限分别为 8.37 和 9.80 μM。密度泛函理论（DFT）计算表明，CeO（111）表面上的 O 缺陷可以催化 HO 的异裂生成 HO 和氧自由基（•O），而不是在清洁表面上生成两个羟基自由基（•OH）。它还可以作为 O 和 HO 吸附的捕获位点，提高 CeO/Pal 的氧亲和力和亲水性。本研究为设计基于矿物的纳米酶提供了一种可行的策略，并深入了解了可能的催化机制。
