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81.
Dr. Zachary T. Gossage Nanako Ito Prof. Tomooki Hosaka Prof. Ryoichi Tatara Prof. Shinichi Komaba 《Angewandte Chemie (International ed. in English)》2023,62(43):e202307446
The solid-electrolyte interphase (SEI) is key to stable, high voltage lithium-ion batteries (LIBs) as a protective barrier that prevents electrolyte decomposition. The SEI is thought to play a similar role in highly concentrated water-in-salt electrolytes (WISEs) for emerging aqueous batteries, but its properties remain unknown. In this work, we utilized advanced scanning electrochemical microscopy (SECM) and operando electrochemical mass spectrometry (OEMS) techniques to gain deeper insight into the SEI that occurs within highly concentrated WISEs. As a model, we focus on a 55 mol/kg K(FSA)0.6(OTf)0.4 electrolyte and a 3,4,9,10-perylenetetracarboxylic diimide negative electrode. For the first time, our work showed distinctly passivating structures with slow apparent electron transfer rates alike to the SEI found in LIBs. In situ analyses indicated stable passivating structures when PTCDI was stepped to low potentials (≈−1.3 V vs. Ag/AgCl). However, the observed SEI was discontinuous at the surface and H2 evolution occurred as the electrode reached more extreme potentials. OEMS measurements further confirmed a shift in the evolution of detectable H2 from −0.9 V to <−1.4 V vs. Ag/AgCl when changing from dilute to concentrated electrolytes. In all, our work shows a combined approach of traditional battery measurements with in situ analyses for improving characterization of other unknown SEI structures. 相似文献
82.
Dongfang Cheng Ziyang Wei Zisheng Zhang Prof. Peter Broekmann Prof. Anastassia N. Alexandrova Prof. Philippe Sautet 《Angewandte Chemie (International ed. in English)》2023,62(20):e202218575
The dynamic restructuring of Cu surfaces in electroreduction conditions is of fundamental interest in electrocatalysis. We decode the structural dynamics of a Cu(111) electrode under reduction conditions by joint first-principles calculations and operando electrochemical scanning tunneling microscopy (ECSTM) experiments. Combining global optimization and grand canonical density functional theory, we unravel the potential- and pH-dependent restructuring of Cu(111) in acidic electrolyte. At reductive potential, Cu(111) is covered by a high density of H atoms and, below a threshold potential, Cu adatoms are formed on the surface in a (4×4) superstructure, a restructuring unfavorable in vacuum. The strong H adsorption is the driving force for the restructuring, itself induced by the electrode potential. On the restructured surface, barriers for hydrogen evolution reaction steps are low. Restructuring in electroreduction conditions creates highly active Cu adatom sites not present on Cu(111). 相似文献
83.
Abdul Malek Yanrong Xue Xu Lu 《Angewandte Chemie (International ed. in English)》2023,62(40):e202309854
In the pursuit of long-term stability for oxygen evolution reaction (OER) in seawater, retaining the intrinsic catalytic activity is essential but has remained challenging. Herein, we developed a NixCryO electrocatalyst that manifested exceptional OER stability in alkaline condition while improving the activity over time by dynamic self-restructuring. In 1 M KOH, NixCryO required overpotentials of only 270 and 320 mV to achieve current densities of 100 and 500 mA cm−2, respectively, with excellent long-term stability exceeding 475 h at 100 mA cm−2 and 280 h at 500 mA cm−2. The combination of electrochemical measurements and in situ studies revealed that leaching and redistribution of Cr during the prolonged electrolysis resulted in increased electrochemically active surface area. This eventually enhanced the catalyst porosity and improved OER activity. NixCryO was further applied in real seawater from the Red Sea (without purification, 1 M KOH added), envisaging that the dynamically evolving porosity can offset the adverse active site-blocking effect posed by the seawater impurities. Remarkably, NixCryO exhibited stable operation for 2000, 275 and 100 h in seawater at 10, 100 and 500 mA cm−2, respectively. The proposed catalyst and the mechanistic insights represented a step towards realization of non-noble metal-based direct seawater splitting. 相似文献
84.
Shuyan Gong Mingze Sun Yiyang Lee Nigel Becknell Jiangwei Zhang Zhongqi Wang Liang Zhang Zhiqiang Niu 《Angewandte Chemie (International ed. in English)》2023,62(4):e202214516
Single crystal surfaces with highly coordinated sites very often hold high specific activities toward oxygen reduction reaction (ORR) and others. Transposing their high specific activity to practical high-surface-area electrocatalysts remains challenging. Here, ultrathin Pt(100) alloy surface is constructed via epitaxial growth. The surface shows 3.1–6.9 % compressive strain and bulk-like characteristics as demonstrated by site-probe reactions and different spectroscopies. Its ORR activity exceeds that of bulk Pt3Ni(100) and Pt(111) and presents a 19-fold increase in specific activity and a 13-fold increase in mass activity relative to commercial Pt/C. Moreover, the electrochemically active surface area (ECSA) is increased by 4-fold compared to traditional thin films (e.g. NSTF), which makes the catalyst more tolerant to voltage loss at high current densities under fuel cell operation. This work broadens the family of extended surface catalysts and highlights the knowledge-driven approach in the development of advanced electrocatalysts. 相似文献
85.
Hydrogen spillover, involving the surface migration of dissociated hydrogen atoms from active metal sites to the relatively inert catalyst support, plays a crucial role in hydrogen-involved catalytic processes. However, a comprehensive understanding of how H atoms are driven to spill over from active sites onto the catalyst support is still lacking. Here, we examine the atomic-scale perspective of the H spillover process on a Pt/Cu(111) single atom alloy surface using machine-learning accelerated molecular dynamics calculations based on density functional theory. Our results show that when an impinging H2 dissociates at an active Pt site, the Pt atom undergoes deactivation due to the dissociated hydrogen atoms that attach to it. Interestingly, collisions between H2 and sticking H atoms facilitate H spillover onto the host Cu, leading to the reactivation of the Pt atom and the realization of a continuous H spillover process. This work underscores the importance of the interaction between gas molecules and adsorbates as a driving force in elucidating chemical processes under a gaseous atmosphere, which has so far been underappreciated in thermodynamic studies. 相似文献
86.
《Arabian Journal of Chemistry》2023,16(6):104720
Lead/copper tannate (TA-Pb/Cu) and lead/copper salicylate (SA-Pb/Cu) interface catalyst shells are established on the surface of 1,3,5,7-tetranitro-1,3,5,7-tetrazacyclooctane (HMX) via in situ coprecipitation to prepare HMX@TA-Pb/Cu and HMX@SA-Pb/Cu composites. The structures and properties of the obtained HMX@TA-Pb/Cu and HMX@SA-Pb/Cu composites are characterized in detail. Molecular dynamics simulations are performed to study the adsorption mechanism of TA-Pb/Cu and SA-Pb/Cu on HMX surface. The residues after HMX@TA-Pb/Cu and HMX@SA-Pb/Cu combusted in air are collected and characterized to study the catalytic effect of TA-Pb/Cu and SA-Pb/Cu on combustion. The study results show that TA-Pb/Cu shells are coated on HMX surface due to the excellent membrane-forming properties of TA, while SA-Pb/Cu shells are embedded in the gullies and holes of HMX surface. TA-Pb/Cu and SA-Pb/Cu shells can decrease the mechanical sensitivities and catalyze the decomposition and combustion of HMX, and the catalytic effects of in situ coprecipitation are better than that of physical mixing. In addition, the phase transition temperature of HMX in HMX@TA-Pb/Cu is increased while that of HMX@SA-Pb/Cu is decreased, illustrating that TA-Pb/Cu can enhance the thermal stability of HMX while SA-Pb/Cu can catalyze the phase transition of HMX. 相似文献
87.
《Arabian Journal of Chemistry》2023,16(1):104395
Nanoscience research aims to produce nanoparticles without adverse effects for medical applications. The pulsed laser ablation (PLA) technique was utilized in this study to synthesize gold nanoparticles (AuNPs) using bovine serum albumin (BSA) in simulated body fluid (SBF) at the fundamental wavelength of the Nd: YAG laser (1064 nm). BSA acted as a stabilizer, reducing and capping agent to produce spherically shaped AuNPs (diameter 3–10 nm). The successful synthesis of AuNPs was confirmed through color changes and UV–vis spectroscopy. The agglomeration and precipitation of AuNPs are attributed to the presence of BSA in the solution, and electrostatic repulsion interactions between BSA and Au nanoclusters. The effect of salt concentration of SBF on BSA stability as well as the interaction of BSA conjugated AuNPs to form complexes was studied using molecular dynamic simulations. Our results show that the stability of AuNPs-BSA conjugates increase with the salt concentration of BSA. Moreover, the synthesized AuNPs exhibit low toxicity and high biocompatibility, supporting their application in drug delivery. Investigation of the cytotoxic effect of the synthesized AuNPs show that normal fibroblast cells (L929) remain intact after treatment whereas a dose-dependent inhibition effect on the growth of cervix cancer cells (HeLa) is observed. In general, this study presents an effective, environmentally-friendly, and facile approach to the synthesis of multifunctional AuNPs using the PLA technique, as a promising efficacious therapeutic treatment of cervical cancer. 相似文献
88.
The nano SnO2-modified LiNi1/3Co1/3Mn1/3O2 was successfully prepared by a carrier transfer method. The pristine and modified samples were characterized with various techniques such as XRD, SEM, XPS and EDS. The results showed that the SnO2 particles did not enter the crystal structure of LiNi1/3Co1/ 3Mn1/3O2, many nano SnO2 particles were uniformly covered on the surface of LiNi1/3Co1/3Mn1/3O2 and the modified thin layer could inhibit the dissolution of transition metal oxides. The electrochemical tests indicated that the existence of nano SnO2 could improve the discharge capacity and rate capability owing to the decreased interfacial polarization. The cycling stability was remarkably improved at room temperature and 55 ℃. The XRD patterns of the fresh NCM electrode and after 50 cycles proved that the structural change of NCM was not so effective on the capacity fade. 相似文献
89.
90.
Non‐Invasive Salivary Electrochemical Quantification of Paraquat Poisoning Using Boron Doped Diamond Electrode 下载免费PDF全文
Thiago Matheus Guimarães Selva William Reis de Araujo Thiago Regis Longo Cesar da Paixão 《Electroanalysis》2015,27(7):1642-1648
The present work describes the first electrochemical method for quantifying paraquat herbicide poisoning in human saliva samples. Paraquat shows two couples of well‐defined peaks in aqueous solution using a boron doped diamond (BDD) electrode. By using square wave voltammetry (SWV) technique under optimum experimental conditions, a linear analytical curve was obtained for paraquat concentrations ranging from 0.800 to 167 µmol L?1, with a detection limit of 70 nmol L?1. This method was applied to quantify paraquat spikes in human saliva samples and in two different water samples (tap and river). The recovery values obtained ranged from 83.0 to 104 % and 99.1 to 105 %, respectively, which highlight the accuracy of the proposed method. 相似文献