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In situ Raman spectroscopy reveals the mechanism of titanium substitution in P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2): Cathode materials for sodium batteries

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Journal of Energy Chemistry 2021年第2期30卷 323-328,I0011页

作者： Xiao-Bin zhong Chao He Fan Gao zhong-qun tian Jian-Feng Li School of Mechanical and Power Engineering North University of ChinaTaiyuan 030051ShanxiChina State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005FujianChina

Layered P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 is a promising cathode material. It exhibits a high capacity and suitable operating voltage and undergoes a phase transition from P2 to O2 during charge/*** have used Ti substitution to improve the cathode, yet the chemical principles that underpin elemental substitution and functional improvement remain unclear. To clarify these principles, we used in situ Raman spectroscopy to monitor chemical changes in P2–Na2/3 Ni1/3 Mn1/3 Ti1/3 O2 and P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_2 during charge/discharge. Based on the change in the A_(1g) and E_g peaks during charge/discharge, we concluded that Ti substitution compressed the transition metal layer and expanded the planar oxygen layer in the unit cell. Titanium stabilized the P2 phase structure, which improved the cycling stability of P2–NaNMT. Our results provide clear theoretical support for future research on modifying electrodes by elemental substitution.

关键词： In situ Raman spectroscopy P2–Na_(2/3)Ni_(1/3)Mn_(2/3)O_(2) Titanium substitution

Unveiling the molecule–plasmon interactions in surface-enhanced infrared absorption spectroscopy

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National Science Review 2020年第7期7卷 1228-1238页

作者： Jun Yi En-Ming You Song-Yuan Ding zhong-qun tian State Key Laboratory of Physical Chemistry of Solid Surfaces (PCOSS) Collaborative Innovation Centre of Chemistry for Energy Materials (iChEM) and Department of Chemistry College of Chemistry and Chemical Engineering Xiamen University NSF Nanoscale Science and Engineering Center University of California

Nanostructure-based surface-enhanced infrared absorption(SEIRA) spectroscopy has attracted tremendous interest as an ultrasensitive detection tool that supplies chemical-fingerprint information. The interactions between molecular vibrations and plasmons lead to not only the enhancement of spectral intensity, but also the distortion of spectral Lorentzian lineshapes into asymmetric Fano-type or more complicated lineshapes in the SEIRA spectra; this effect hampers the correct readout of vibrational frequencies and intensities for an accurate interpretation of the measured spectra and quantitative *** this work, we investigate the Fano interference between molecular vibrations and plasmons based on exact electrodynamic simulations and theoretical models. We report that, even if the molecular vibrational energy is equal to the plasmon resonant energy, the molecule–nanostructure distance-dependent dipole–dipole interactions, the plasmon-mediated coherent intermolecular interactions and the decay rates of plasmons have a significant impact on the SEIRA lineshapes. This study paves the way for controllable Fano interference at the nanoscale and more studies on plasmon-dressed molecular electronic or vibrational excited states.

关键词： surface plasmons surface-enhanced infrared absorption Fano resonance coupling strength spectral lineshape

A breakthrough in the chemical imaging of single molecule:sub-nm tip-enhanced Raman spectroscopy

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National Science Review 2014年第1期1卷 4-5页

作者： Song-Yuan Ding zhong-qun tian State Key Lab of Physical Chemistry of Solid Surfaces Xiamen University

In 1930,just two years ater his report on‘A New Type of Secondary Radiation’from the scatering of focused beams of sunlight in liquid benzene[1]Sir CV Raman received the Nobel Prize in Physics‘for his work on the scatering of light and for the discovery of the efect named after him’.his great honor was awarded so soon because the scientiic community immediately recognized that the Raman efect could be developed into a powerful ingerprint vibrational spectroscopy

关键词： A breakthrough in the chemical imaging of single molecule SERS nm

Spatially-separated and photo-enhanced semiconductor corrosion processes for high-efficient and contamination-free electrochemical nanoimprint lithography

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Science China Chemistry 2022年第4期65卷 810-820页

作者： Hantao Xu Lianhuan Han Jian-Jia Su zhong-qun tian Dongping Zhan Key Laboratory of Physical Chemistry of Solid Surfaces(PCOSS) Engineering Research Center of Electrochemical Technologies of Ministry of EducationDepartment of ChemistryCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Department of Mechanical and Electrical Engineering School of Aerospace EngineeringXiamen UniversityXiamen 361005China

Free of any thermoplastic or photocuring resists, electrochemical nanoimprint lithography(ECNL) has emerged as an alternative nanoimprint way to fabricate three-dimensional micro/nano-structures(3D-MNSs) directly on a semiconductor wafer by a spatially-confined corrosion reaction induced by the metal/semiconductor contact potential. However, the consumption of electron acceptors in the ultrathin electrolyte between imprint mold and semiconductor wafer will slow down or even cease the corrosion rate. To solve this problem, we change the short-circuited corrosion cell into a spatially-separated primary cell: the imprint mold compacted gallium arsenide(GaAs) wafer in the anodic chamber while the platinum(Pt) plate connected to the imprint mold in the cathodic chamber. Thus, the GaAs corrosion rate will be stabilized in its limiting steady-state current density because of the abundant source of electron acceptors in the catholic chamber. The corrosion processes can be photo-enhanced by white-light illumination. Consequently, both the accuracy and the efficiency are promoted dramatically, which are demonstrated by the excellent performance of the fabricated binary optical elements. Moreover, the contamination problem caused by the electron acceptors is totally avoided. All the results prove that this novel ECNL mode is competitive and prospective in imprinting 3D-MNSs directly on semiconductor wafer.

关键词： nanoimprint lithography electrochemical microfabrication semiconductor corrosion semiconductor microdevices 3D functional micro/nano-structures

Tribocatalysis: challenges and perspectives

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Science China Chemistry 2021年第10期64卷 1609-1613页

作者： Feng-Ru Fan Shunji Xie Guan-Wu Wang zhong-qun tian State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy Materials(iChEM)College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Soft Matter ChemistryCollaborative Innovation Center of Chemistry far Energy Materials(iChEM)Department of ChemistryUniversity of Science and Technology'of ChinaHefei 230026China

With an increasing global energy demands and environmental pollution, the development of alternative clean energy technologies has aroused widespread research *** and converting natural energy from the environment, such as solar energy, mechanical energy, thermal energy, chemical and biological energy, is one of the main sources of clean energy.

关键词： catalysis pollution energy

Advances of surface-enhanced Raman and IR spectroscopies: from nano/microstructures to macro-optical design

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Light(Science & Applications) 2021年第9期10卷 1588-1606页

作者： Hai-Long Wang En-Ming You Rajapandiyan Panneerselvam Song-Yuan Ding zhong-qun tian State Key Laboratory of Physical Chemistry of Solid Surfaces Collaborative Innovation Center of Chemistry for Energy MaterialsCollege of Chemistry and Chemical EngineeringXiamen UniversityXiamen361005China Department of Chemistry SRM University-APAmaravathiAndhra PradeshIndia

Raman and infrared(IR)spectroscopy are powerful analytical techniques,but have intrinsically low detection *** have been three major steps(i)to advance the optical system of the light excitation,collection,and detection since 1920s,(ii)to utilize nanostructure-based surface-enhanced Raman scattering(SERS)and surface-enhanced infrared absorption(SEIRA)since 1990s,and(iii)to rationally couple(i)and(ii)for maximizing the total detection sensitivity since *** surveying the history of SERS and SEIRA,we outline the principle of plasmonics and the different mechanisms of SERS and *** describe various interactions of light with nano/microstructures,localized surface plasmon,surface plasmon polariton,and lightning-rod *** coupling effects can significantly increase the surface sensitivity by designing nanoparticle–nanoparticle and nanoparticle–substrate *** the nano/microstructures have specific optical near-field and far-field behaviors,we focus on how to systematically design the macro-optical systems to maximize the excitation efficiency and detection *** enumerate the key optical designs in particular ATR-based operation modes of directional excitation and emission from visible to IR spectral *** also present some latest advancements on scanning-probe microscopy-based nanoscale ***,prospects and further developments of this field are given with emphasis on emerging techniques and methodologies.

关键词： surface excitation utilize

Nanofabrication of the gold scanning probe for the STM-SECM coupling system with nanoscale spatial resolution

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Science China Chemistry 2017年第5期60卷 649-655页

作者： Fang-Fang Wang Wei Wang Xi He Lianhuan Han Jian-Zhang Zhou zhong-qun tian Zhao-Wu tian Dongping Zhan State Key Laboratory of Physical Chemistry of Solid Surfaces College of Chemistry and Chemical EngineeringXiamen University Chemical Engineering and Environmental Engineering College of Chemistry Liaoning Shihua University

Scanning probe is the key issue for the electrochemical scanning probe techniques(EC-SPM) such as EC-scanning tunnel microscopy(STM), EC-atomic force microscopy(AFM) and scanning electrochemical microscopy(SECM), especially the insulative encapsulation of the nanoelectrode probe for both positioning and electrochemical feedbacks. To solve this problem,we develop a novel fabrication method of the gold nanoelectrodes: firstly, a micropipette with nanomter-sized orifice was prepared as the template by a laser puller; secondly, the inside wall of micropipette apex was blocked by compact and conic Au nano-piece through electroless plating; thirdly, the Au nano-piece was grown by bipolar electroplating and connected with a silver wire as a current collector. The fabricated Au nanoelectrode has very good voltammetric responses for the electrodic processes of both mass transfer and adsorption. The advantage lies in that it is well encapsulated by a thin glass sealing layer with a RG value lowered to 1.3, which makes it qualified in the SECM-STM coupling mode. On one hand, it can serve as STM tip for positioning which ensures the high spatial resolution; on the other hand, it is a high-quality nanoelectrode to explore the local chemical activity of the substrate. The nanofabrication method may promote the SPM techniques to obtain simultaneously the physical and chemical images with nanoscale spatial resolution, which opens a new approach to tip chemistry in electrochemical nanocatalysis and tip-enhanced spectroscopy.

关键词： scanning probe SECM bipolar nanoelectrode electrochemical imaging

Surface plasmon-enhanced photochemical reactions on noble metal nanostructures

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Science China Chemistry 2015年第4期58卷 574-585页

作者： De-Yin Wu Meng Zhang Liu-Bin Zhao Yi-Fan Huang Bin Ren zhong-qun tian State Key Laboratory of Physical Chemistry of Solid Surfaces Department of Chemistry College of Chemistry and Chemical Engineering Collaborative Innovation Center of Chemistry for Energy Materials Xiamen University

Nanoscale noble metals can exhibit excellent photochemical and photophysical properties, due to surface plasmon resonance(SPR) from specifically collective electronic excitations on these metal surfaces. The SPR effect triggers many new surface processes, including radiation and radiationless relaxations. As for the radiation process, the SPR effect causes the significant focus of light and enormous enhancement of the local surface optical electric field, as observed in surface-enhanced Raman spectroscopy(SERS) with very high detection sensitivity(to the single-molecule level). SERS is used to identify surface species and characterize molecular structures and chemical reactions. For the radiationless process, the SPR effect can generate hot carriers, such as hot electrons and hot holes, which can induce and enhance surface chemical reactions. Here, we review our recent work and related literature on surface catalytic-coupling reactions of aromatic amines and aromatic nitro compounds on nanostructured noble metal surfaces. Such reactions are a type of novel surface plasmon-enhanced chemical reaction. They could be simultaneously characterized by SERS when the SERS signals are assigned. By combining the density functional theory(DFT) calculations and SERS experimental spectra, our results indicate the possible pathways of the surface plasmonenhanced photochemical reactions on nanostructures of noble metals. To construct a stable and sustainable system in the conversion process of the light energy to the chemical energy on nanoscale metal surfaces, it is necessary to simultaneously consider the hot electrons and the hot holes as a whole chemical reaction system.

关键词： surface plasmon resonance plasmon-enhanced chemical reaction p-aminothiophenol density functional theory noble metal nanostructures

"Initial Potential" Effect on the Dissociative Adsorption of Methanol on A Roughened Platinum Electrode in Acidic Solution

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Chinese Chemical Letters 2001年第10期12卷 913-916页

作者： Ze Lin LI Bin REN Chun Xing SHE Xiao Ming XIAO zhong qun tian Department of Chemistry Hunan Normal UniversityChangsha 410081 State Key Laboratory for Physical Chemistry of Solid Surfaces and Department of Chemistry Xiamen UniversityXiamen UniversityXiamen 361005

In situ Raman spectroscopic and voltammetric studies indicate that dissociative adsorption of methanol on the rough platinum electrode occurs in the hydrogen ad/desorption potential range, and the dissociative extent depends on the initial potential of the electrode before contacting methanol, in addition to the contacting time. As the dissociative product, carbon monoxide competes the site of strongly bound hydrogen preferentially, and shifts the ad/desorption potentials of weakly bound hydrogen towards more positive ones gradually with the increase of CO coverage. Whereas, formaldehyde dissociates more easily by far and completely suppresses H-adsorption. The confocal Raman spectroscopy developed on transition metals shows some intriguing advantages in investigating electrocatalytic oxidation of small organic molecules.

关键词： Methanol formaldehyde dissociative adsorption in situ Raman spectroscopy.