Silver Nanowire‐Templated Molecular Nanopatterning and Nanoparticle Assembly for Surface‐Enhanced Raman Scattering

Yan

et al. 2020

J. Phys. Chem. Lett.

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A surface plasmon can drive many photochemical reactions, in which effective charge separation and migration is a key. In analogy to the plasmon–semiconductor interface, the plasmon–molecule interface may also be used to improve the separation and migration of hot carriers. In this work, by using in situ Raman spectroscopy, molecular grafting on silver nanostructures is found essential for modulating the charge separation and p-aminothiophenol (PATP) oxidation reaction. When the LUMO of the grafted molecules match well the energy distribution of the plasmon-generated hot electrons, the PATP oxidation process accelerates significantly. Moreover, compared with symmetrical grafting, asymmetrical grafting is more effective in regulating the charge separation and plasmon-mediated chemical reaction. This work provides an effective strategy for deep understanding and fine modulation of plasmon-mediated photochemistry.

mentioning

confidence: 99%

Modulating the Plasmon-Mediated Oxidation of p-Aminothiophenol with Asymmetrically Grafted Thiol Molecules

Zhang

Yan

et al. 2020

J. Phys. Chem. Lett.

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“…Nanocrystals, especially semiconductor ones, usually possess unique chemical, electrical, optical and magnetic properties compared to their bulk counterparts . These properties are highly dependent on the chemical composition, size, shape and surface state of the nanocrystals . Therefore, controlled synthesis of nanocrystals is becoming a hot topic in many fields, and lots of efforts have been made to precisely control the morphology and surface state of the nanocrystals .…”

Section: Figurementioning

confidence: 99%

Crack Formation on Crystalline Bismuth Oxychloride Thin Square Sheets by Using a Wet‐Chemical Method

Zhou

et al. 2020

ChemNanoMat

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The morphology of nanocrystals is crucial in modulating their properties including optical, chemical and catalytic ones. For the intensively studied sheet-like structures, it is also important to engineer their detailed nanostructures on sheet surfaces. In this work, micron-sized bismuth oxychloride (BiOCl) thin square sheets in tetragonal matlockite-like phase and the corner-truncated ones were successfully synthesized by using a simple wet-chemical method. These square sheets could be partially etched, forming surface cracks with the size and density easily tuned. Two different types of cracks were observed on the surfaces of the corner un-truncated and truncated BiOCl square sheets. Surprisingly, radial cracks formed on the corner-truncated BiOCl sheets, which is attributed to the existence of physical stress during the etching and is highly related to the original nanostructure of the BiOCl sheets. This work provides a wet-chemical method for engineering surface cracks, especially radial cracks, on the surfaces of BiOCl nanosheets, which may be expanded to surface engineering of other nanosheets and will show a great potential in various fields. Nanocrystals, especially semiconductor ones, usually possess unique chemical, electrical, optical and magnetic properties compared to their bulk counterparts. [1][2][3][4][5][6] These properties are highly dependent on the chemical composition, size, shape and surface state of the nanocrystals. [3,[7][8][9][10][11] Therefore, controlled synthesis of nanocrystals is becoming a hot topic in many fields, and lots of efforts have been made to precisely control the morphology and surface state of the nanocrystals. [9,[12][13][14][15][16][17] Among various shaped nanocrystals, the sheet-like ones show promising properties and applications due to their structural simplicity, large surface area, easy charge separation, etc. [18][19][20][21] Sheet-like [a] R.

“…More importantly, the energy level structure of a molecule can be fine-tuned easily by substitution, making it easier to be aligned with the band structure of a plasmonic metal. By using plasmon-enhanced Raman spectroscopy, [16][17][18] our group has reported thiophenol molecule-induced acceleration of plasmon-mediated chemical reactions. [19,20] However, the contribution of the thiophenol molecules is not clear and the modulation of these reactions with molecular grafting needs to be further investigated.…”

Section: Introductionmentioning

confidence: 99%

Monitoring the Thiol/Thiophenol Molecule‐Modulated Plasmon‐Mediated Silver Oxidation with Dark‐Field Optical Microscopy

Yan

Sheng

et al. 2021

Chemistry A European J

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Surface plasmon can trigger or accelerate many photochemical reactions, especially useful in energy and environmental industries. Recently, molecular adsorption has proven effective in modulating plasmon-mediated photochemistry, however the realized chemical reactions are limited and the underlying mechanism is still unclear. Herein, by using in situ dark-field optical microscopy, the plasmonmediated oxidative etching of silver nanoparticles (Ag NPs), a typical hot-hole-driven reaction, is monitored continuously and quantitatively. The presence of thiol or thiophenol molecules is found essential in the silver oxidation. In addition, the rate of silver oxidation is modulated by the choice of different thiol or thiophenol molecules. Compared with the molecules having electron donating groups, the ones having electron accepting groups accelerate the silver oxidation dramatically. The thiol/thiophenol modulation is attributed to the modulation of the charge separation between the Ag NPs and the adsorbed thiol or thiophenol molecules. This work demonstrates the great potential of molecular adsorption in modulating the plasmon-mediated photochemistry, which will pave a new way for developing highly efficient plasmonic photocatalysts.