Exposing facet and surface strain are critical factors affecting catalytic performance but unraveling the composition-dependent activity on specific facets under strain-controlled environment is still challenging due to the synthetic difficulties. Herein, we achieved a (001) facet-defined Co-Mn spinel oxide surface with different surface compositions using epitaxial growth on CoO nanocube template. We adopted composition gradient synthesis to relieve the strain layer by layer, minimizing the surface strain effect on catalytic activity. In this system, experimental and calculational analyses of model oxygen reduction reaction (ORR) activity reveals a volcano-like trend with Mn/Co ratios because of an adequate charge transfer from octahedral-Mn to neighboring Co. CoMn as an optimized Mn/Co ratio exhibits both outstanding ORR activity (0.894 V vs RHE in 1 M KOH) and stability (2% activity loss against chronoamperometry). By controlling facet and strain, this study provides a well-defined platform for investigating composition-structure-activity relationships in electrocatalytic processes.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acs.nanolett.2c00238 | DOI Listing |
Angew Chem Int Ed Engl
January 2025
Nanjing University, Biomedical Engineering, 22 Hankou Rd, 210093, Nanjing, CHINA.
Nanozymes are next generation of enzyme mimics. Due to the lack of activity descriptors, most nanozymes were discovered through trial-and-error strategies or by accident. While eg occupancy in an octahedral crystal field was proven as an effective descriptor, the t2 in a tetrahedral crystal field has rarely been explored.
View Article and Find Full Text PDFAquat Toxicol
December 2024
Çanakkale Onsekiz Mart University, School of Graduate Studies, Çanakkale, Turkey. Electronic address:
The effectiveness of magnetic nanoparticles in removing pollutants during water treatment is well established, but their introduction into aquatic ecosystems raises significant toxicity concerns. This study investigates the histological and physiological effects of zinc ferrite magnetic nanoparticles (ZnFeOMNPs) on the Mediterranean mussel (Mytilus galloprovincialis) and examines the impact of concurrent exposure to these nanoparticles and the insecticide thiomethoxam (TMX). Mussels were exposed to nominal concentrations of ZnFeOMNPs (1, 10, 100 mg/L) both individually and with TMX.
View Article and Find Full Text PDFEnviron Res
January 2025
Department of Chemistry, University college in Al-Jamoum, Umm Al-Qura University, 21955, Makkah, Saudi Arabia.
Accurate quantification of neonicotinoid insecticides is pivotal to ensure environmental safety by examining and mitigating their potential harmful effects on pollinators and aquatic ecosystems. In this scenario, detection of neonicotinoid insecticide, thiamethoxam (TMX), is significant for safeguarding ecological balance and human health. Hence, we developed a highly sensitive electrochemical sensor for detection of TMX in environmental samples, utilizing a novel nanocomposite with superior electrocatalytic properties and integrating an optimized neural network for accurate data analysis.
View Article and Find Full Text PDFMaterials (Basel)
January 2025
School of Materials Science & Engineering, Pusan National University, Busan 46241, Republic of Korea.
In this study, cordierite-based ceramics (2MgO·2AlO·5SiO) were synthesized using high-purity MgO, AlO, and SiO as starting materials. The influence of the MgO/AlO ratio on various properties, including the thermal behavior, pyrometric cone refractory behavior, phase formation, physical properties, and microstructure of the synthesized ceramics, was systematically analyzed. Increasing the MgO/AlO ratio progressively weakened the cordierite network, leading to lower temperatures for liquid formation and melting.
View Article and Find Full Text PDFMolecules
January 2025
Hunan Provincial Key Laboratory of Materials Protection for Electric Power and Transportation & Hunan Provincial Key Laboratory of Cytochemistry, School of Chemistry and Chemical Engineering, Changsha University of Science and Technology, Changsha 410114, China.
Compared to natural enzymes, the development of efficient artificial simulated enzymes, such as those based on bimetallic materials with high catalytic activity and good stability, is an important way until now. Herein, we employed ZnCoO microspheres as carriers to synthesize Pt-doped composites with different amounts using a one-pot method. The morphology and structure of the synthesized materials were characterized using XRD, SEM, BET, FT-IR, XPS, and Zeta potential techniques.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!