Publications by authors named "Jin-Chao Dong"

12 Publications

  • Page 1 of 1

In Situ Surface-Enhanced Raman Spectroscopy Characterization of Electrocatalysis with Different Nanostructures.

Annu Rev Phys Chem 2021 Apr 20;72:331-351. Epub 2021 Jan 20.

State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, iChEM, College of Energy, Xiamen University, Xiamen 361005, China; email:

As energy demands increase, electrocatalysis serves as a vital tool in energy conversion. Elucidating electrocatalytic mechanisms using in situ spectroscopic characterization techniques can provide experimental guidance for preparing high-efficiency electrocatalysts. Surface-enhanced Raman spectroscopy (SERS) can provide rich spectral information for ultratrace surface species and is extremely well suited to studying their activity. To improve the material and morphological universalities, researchers have employed different kinds of nanostructures that have played important roles in the development of SERS technologies. Different strategies, such as so-called borrowing enhancement from shell-isolated modes and shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS)-satellite structures, have been proposed to obtain highly effective Raman enhancement, and these methods make it possible to apply SERS to various electrocatalytic systems. Here, we discuss the development of SERS technology, focusing on its applications in different electrocatalytic reactions (such as oxygen reduction reactions) and at different nanostructure surfaces, and give a brief outlook on its development.
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http://dx.doi.org/10.1146/annurev-physchem-090519-034645DOI Listing
April 2021

Spectroscopic Verification of Adsorbed Hydroxy Intermediates in the Bifunctional Mechanism of the Hydrogen Oxidation Reaction.

Angew Chem Int Ed Engl 2021 Mar 29;60(11):5708-5711. Epub 2021 Jan 29.

State Key Laboratory of Physical Chemistry of Solid Surfaces,iChEM, College of Chemistry and Chemical Engineering, College of Energy, Xiamen University, Xiamen, 361005, China.

Elucidating hydrogen oxidation reaction (HOR) mechanisms in alkaline conditions is vital for understanding and improving the efficiency of anion-exchange-membrane fuel cells. However, uncertainty remains around the alkaline HOR mechanism owing to a lack of direct in situ evidence of intermediates. In this study, in situ electrochemical surface-enhanced Raman spectroscopy (SERS) and DFT were used to study HOR processes on PtNi alloy and Pt surfaces, respectively. Spectroscopic evidence indicates that adsorbed hydroxy species (OH ) were directly involved in HOR processes in alkaline conditions on the PtNi alloy surface. However, OH species were not observed on the Pt surface during the HOR. We show that Ni doping promoted hydroxy adsorption on the platinum-alloy catalytic surface, improving the HOR activity. DFT calculations also suggest that the free energy was decreased by hydroxy adsorption. Consequently, tuning OH adsorption by designing bifunctional catalysts is an efficient method for promoting HOR activity.
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http://dx.doi.org/10.1002/anie.202015571DOI Listing
March 2021

In Situ Raman Study of CO Electrooxidation on Pt(hkl) Single-Crystal Surfaces in Acidic Solution.

Angew Chem Int Ed Engl 2020 Dec 25;59(52):23554-23558. Epub 2020 Oct 25.

College of Energy, State Key Laboratory of Physical Chemistry of Solid Surfaces, College of Chemistry and Chemical Engineering, College of Environment and Ecology, State key Laboratory of Marine Environmental Science, iChEM, Xiamen University, Xiamen, 361005, China.

The adsorption and electrooxidation of CO molecules at well-defined Pt(hkl) single-crystal electrode surfaces is a key step towards addressing catalyst poisoning mechanisms in fuel cells. Herein, we employed in situ electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) coupled with theoretical calculation to investigate CO electrooxidation on Pt(hkl) surfaces in acidic solution. We obtained the Raman signal of top- and bridge-site adsorbed CO* molecules on Pt(111) and Pt(100). In contrast, on Pt(110) surfaces only top-site adsorbed CO* was detected during the entire electrooxidation process. Direct spectroscopic evidence for OH* and COOH* species forming on Pt(100) and Pt(111) surfaces was afforded and confirmed subsequently via isotope substitution experiments and DFT calculations. In summary, the formation and adsorption of OH* and COOH* species plays a vital role in expediting the electrooxidation process, which relates with the pre-oxidation peak of CO electrooxidation. This work deepens knowledge of the CO electrooxidation process and provides new perspectives for the design of anti-poisoning and highly effective catalysts.
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http://dx.doi.org/10.1002/anie.202010431DOI Listing
December 2020

Raman study of the photoinduced behavior of dye molecules on TiO() single crystal surfaces.

Chem Sci 2020 Apr 17;11(25):6431-6435. Epub 2020 Apr 17.

Department of Physics, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, College of Energy, College of Materials, Xiamen University Xiamen 361005 China

In dye-sensitized solar cells (DSSCs), the TiO/dye interface significantly affects photovoltaic performance. However, the adsorption and photoinduced behavior of dye molecules on the TiO substrate remains unclear. Herein, shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS) was used to study the adsorption and photoinduced behavior of dye (N719) molecules on different TiO() surfaces. On TiO(001) and TiO(110) surfaces, the SHINERS and mass spectrometry results indicate S[double bond, length as m-dash]C bond cleavage in the anchoring groups of adsorbed N719, whereas negligible bond cleavage occurs on the TiO(111) surface. Furthermore, DFT calculations show the stability of the S[double bond, length as m-dash]C anchoring group on three TiO() surfaces in the order TiO(001) < TiO(110) < TiO(111), which correlated well with the observed photocatalytic activities. This work reveals the photoactivity of different TiO() surface structures and can help with the rational design of DSSCs. Thus, this strategy can be applied to real-time probing of photoinduced processes on semiconductor single crystal surfaces.
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http://dx.doi.org/10.1039/d0sc00588fDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8159273PMC
April 2020

Direct Raman Spectroscopic Evidence of Oxygen Reduction Reaction Intermediates at High-Index Pt() Surfaces.

J Am Chem Soc 2020 Jan 3;142(2):715-719. Epub 2020 Jan 3.

State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering, College of Energy , Xiamen University , Xiamen 361005 , China.

The study of the oxygen reduction reaction (ORR) at high-index Pt() single crystal surfaces has received considerable interest due to their well-ordered, typical atomic structures and superior catalytic activities. However, it is difficult to obtain direct spectral evidence of ORR intermediates during reaction processes, especially at high-index Pt() surfaces. Herein, Raman spectroscopy has been employed to investigate ORR processes at high-index Pt() surfaces containing the [011̅] crystal zone-i.e., Pt(211) and Pt(311). Through control and isotope substitution experiments, spectroscopic evidence of OH and OOH intermediates at Pt(211) and Pt(311) surfaces was successfully obtained. After detailed analysis based on the Raman spectra and theoretical simulation, it was deduced that the difference in adsorption of OOH at high-index surfaces has a significant effect on the ORR activity. This research illuminates and deepens the understanding of the ORR mechanism on high-index Pt() surfaces and provides theoretical guidance for the rational design of high activity ORR catalysts.
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http://dx.doi.org/10.1021/jacs.9b12803DOI Listing
January 2020

Toward a quantitative theoretical method for infrared and Raman spectroscopic studies on single-crystal electrode/liquid interfaces.

Chem Sci 2019 Dec 10;11(5):1425-1430. Epub 2019 Dec 10.

State Key Laboratory of Physical Chemistry of Solid Surfaces (PCOSS), Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University Xiamen 361005 China

electrochemical infrared spectroscopy and Raman spectroscopy are powerful tools for probing potential-dependent adstructures at solid/liquid electrochemical interfaces. However, it is very difficult to quantitatively interpret the observed spectral features including potential-dependent vibrational frequency and spectral intensity, even from model systems such as single-crystal electrode/liquid interfaces. The clear understanding of electrochemical vibrational spectra has remained as a fundamental issue for four decades. Here, we have developed a method to combine computational vibrational spectroscopy tools with interfacial electrochemical models to accurately calculate the infrared and Raman spectra. We found that the solvation model and high precision level in the self-consistent-field convergence are critical elements to realize quantitative spectral predictions. This method's predictive power is verified by analysis of a classic spectroelectrochemical system, saturated CO molecules electro-adsorbed on a Pt(111) electrode. We expect that this method will pave the way to precisely reveal the physicochemical mechanism in some electrochemical processes such as electrocatalytic reactions.
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http://dx.doi.org/10.1039/c9sc05429dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8148070PMC
December 2019

Unusual Sonochemical Assembly between Carbon Allotropes for High Strain-Tolerant Conductive Nanocomposites.

ACS Nano 2019 Oct 24;13(10):12062-12069. Epub 2019 Sep 24.

Stephenson Institute for Renewable Energy and Department of Chemistry , University of Liverpool , Liverpool L69 7ZD , United Kingdom.

Facile methods toward strain-tolerant graphene-based electronic components remain scarce. Although being frequently used to disperse low-dimensional carbonaceous materials, ultrasonication (US) has never been reliable for fabricating stretchable carbonaceous nanocomposite (SCNC). Inspired by the unusual sonochemical assembly between graphene oxide (GO) and carbon nanotube (CNT), we verified the roots-like GO-CNT covalent bonding, rather than just π-π conjugation, was formed during US. In addition, the shockwave-induced collision in the binary-component system enables a burst of fragmentation at the early stage, spatially homogeneous hybridization, and time-dependent restoration of graphitic domains. All of the above are distinct from extensive fragmentation of a conventional single-component system and π-π conjugative assembly. The optimized SCNC exhibits conductivity comparable to reduced monolayer GO and outperforms π-π assemblies in retaining electrical conductance at a strain of 160%-among one of the best reported stretchable conductors. Raman analysis and mechanics simulation confirm the dominant role of counterweighing between the intrinsic and external strains on the mechano-response and durability of SCNC. This work suggests the guideline of creating multiple-component sonochemical systems for various functional nanocomposites.
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http://dx.doi.org/10.1021/acsnano.9b06366DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6812068PMC
October 2019

Early Stages of Electrochemical Oxidation of Cu(111) and Polycrystalline Cu Surfaces Revealed by Raman Spectroscopy.

J Am Chem Soc 2019 Aug 25;141(31):12192-12196. Epub 2019 Jul 25.

MOE Key Laboratory of Spectrochemical Analysis and Instrumentation, State Key Laboratory of Physical Chemistry of Solid Surfaces, iChEM, College of Chemistry and Chemical Engineering , Xiamen University , Xiamen 361005 , China.

Investigating the chemical nature of the adsorbed intermediate species on well-defined Cu single crystal substrates is crucial in understanding many electrocatalytic reactions. Herein, we systematically study the early stages of electrochemical oxidation of Cu(111) and polycrystalline Cu surfaces in different pH electrolytes using shell-isolated nanoparticle-enhanced Raman spectroscopy (SHINERS). On Cu(111), for the first time, we identified surface OH species which convert to chemisorbed "O" before forming CuO in alkaline (0.01 M KOH) and neutral (0.1 M NaSO) electrolytes; while at the Cu(poly) surface, we only detected the presence of surface hydroxide. Whereas, in a strongly acidic solution (0.1 M HSO), sulfate replaces the hydroxyl/oxy species. This results improves the understanding of the reaction mechanisms of various electrocatalytic reactions.
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http://dx.doi.org/10.1021/jacs.9b04638DOI Listing
August 2019

Oxygen reactions on Pt{} in a non-aqueous Na electrolyte: site selective stabilisation of a sodium peroxy species.

Chem Sci 2019 Mar 17;10(10):2956-2964. Epub 2019 Jan 17.

Stephenson Institute for Renewable Energy , Department of Chemistry , University of Liverpool , UK . Email:

Sodium-oxygen battery cathodes utilise the reversible redox species of oxygen in the presence of sodium ions. However, the oxygen reduction and evolution reaction mechanism is yet to be conclusively determined. In order to examine the part played by surface structure in sodium-oxygen electrochemistry for the development of catalytic materials and structures, a method of preparing clean, well-defined Pt electrode surfaces for adsorption studies in aprotic solvents is described. Using cyclic voltammetry (CV) and electrochemical shell-isolated nanoparticle enhanced Raman spectroscopy (SHINERS), the various stages of oxygen reduction as a function of potential have been determined. It is found that on Pt{111} and Pt{110}-(1 × 1) terraces, a long lived surface sodium peroxide species is formed reversibly, whereas on Pt{100} and polycrystalline electrodes, this species is not detected.
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http://dx.doi.org/10.1039/c8sc05489dDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6427968PMC
March 2019

Surface-Enhanced Raman Spectroscopy Study of Fresh Human Urine: A Preliminary Study.

Guang Pu Xue Yu Guang Pu Fen Xi 2016 Jun;36(6):1987-91

In this work, we have mainly studied SERS spectra of fresh human urine by using Au nanoparticles excited by 785 and 1 030 nm lasers, respectively. And the UV/Vis adsorption experiment of the Au nanoparticles mixed with different ratio of urine has been performed, and the obvious shifting of corresponding absorption band is observed. The result showed that the Au nanoparticles which have been synthesized by classical Fren’s method can interact with urine, and the Au nanoparticles aggregations caused by the urine have strong SERS effect. Intense and repeatable spectra of the urine samples can be quickly obtained using Au colloids, which characterized by the scanning electron microscope (SEM) and the high-resolution transmission electron microscope (HRTEM) images, and it can be confirmed that the size of the Au nanoparticles is about 55 nm with a finite variation. When different spectra can be detected under different exciting lasers, the various biofluid to Au substrate ratios can generate different intense spectra. From the spectra of 785 nm laser, we can conclude that it has lower background and higher resolution with more detail information of this system contained human urine. For the 1 030 nm laser, a portable Raman instrument is helpful for on-site clinic treatment detection. It also gets well defined information and will be a good and convenient choice for urine analysis. It should note that this peak band located at 1 006 cm-1 may be the dominant nitrogen-containing component in urine. On the other hand, uric acid, urea, hypoxanthine as well as creatinine can be assigned; the other bands are still unknown, which might be attributed to biomarkers important for disease differentiation. Another result shows that different sample preparation can influence the SERS spectra with different ratio. We also have made a comparison of Raman spectra between 785 and 1 030 nm lasers to learn the difference between each other just like background and high-resolution. The current study indicates the SERS of urine might be a good choice and tool for urinalysis with potential diagnostic application, especially with the portable Raman instrument which would be an accurate and convenient approach for urine analysis. It is possible for SERS detection to be applied in not only the health diagnosis but also biological tissue in the future.
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June 2016

Self-assembly of subwavelength nanostructures with symmetry breaking in solution.

Nanoscale 2016 Feb;8(5):2951-9

State Key Laboratory of Physical Chemistry of Solid Surfaces and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China.

Nanostructures with symmetry breaking can allow the coupling between dark and bright plasmon modes to induce strong Fano resonance. However, it is still a daunting challenge to prepare bottom-up self-assembled subwavelength asymmetric nanostructures with appropriate gaps between the nanostructures especially below 5 nm in solution. Here we present a viable self-assembly method to prepare symmetry-breaking nanostructures consisting of Ag nanocubes and Au nanospheres both with tunable size (90-250 nm for Au nanospheres; 100-160 nm for Ag nanocubes) and meanwhile control the nanogaps through ultrathin silica shells of 1-5 nm thickness. The Raman tag of 4-mercaptobenzoic acid (MBA) assists the self-assembly process and endows the subwavelength asymmetric nanostructures with surface-enhanced Raman scattering (SERS) activity. Moreover, thick silica shells (above 50 nm thickness) can be coated on the self-assembled nanostructures in situ to stabilize the whole nanostructures, paving the way toward bioapplications. Single particle scattering spectroscopy with a 360° polarization resolution is performed on individual Ag nanocube and Au nanosphere dimers, correlated with high-resolution TEM characterization. The asymmetric dimers exhibit strong configuration and polarization dependence Fano resonance properties. Overall, the solution-based self-assembly method reported here is opening up new opportunities to prepare diverse multicomponent nanomaterials with optimal performance.
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http://dx.doi.org/10.1039/c5nr06738cDOI Listing
February 2016

In Situ Monitoring of Electrooxidation Processes at Gold Single Crystal Surfaces Using Shell-Isolated Nanoparticle-Enhanced Raman Spectroscopy.

J Am Chem Soc 2015 Jun 11;137(24):7648-51. Epub 2015 Jun 11.

§Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, Bern CH-3012, Switzerland.

Identifying the intermediate species in an electrocatalytic reaction can provide a great opportunity to understand the reaction mechanism and fabricate a better catalyst. However, the direct observation of intermediate species at a single crystal surface is a daunting challenge for spectroscopic techniques. In this work, electrochemical shell-isolated nanoparticle-enhanced Raman spectroscopy (EC-SHINERS) is utilized to in situ monitor the electrooxidation processes at atomically flat Au(hkl) single crystal electrode surfaces. We systematically explored the effects of crystallographic orientation, pH value, and anion on electrochemical behavior of intermediate (AuOH/AuO) species. The experimental results are well correlated with our periodic density functional theory calculations and corroborate the long-standing speculation based on theoretical calculations in previous electrochemical studies. The presented in situ electrochemical SHINERS technique offers a unique way for a real-time investigation of an electrocatalytic reaction pathway at various well-defined noble metal surfaces.
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http://dx.doi.org/10.1021/jacs.5b04670DOI Listing
June 2015
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