scholarly journals The Role of an Inert Electrode Support in Plasmonic Electrocatalysis

Author(s):  
Sagar Ganguli ◽  
Alina Sekretareva

Plasmonic nanostructures loaded onto catalytically inert conductive support materials are believed to be advantageous for maximizing photocatalytic effects in photoelectrochemical systems due to the increased efficiency of Schottky barrier-free architectures in collecting hot charge carriers. However, the systematic mechanistic investigation and description of the inert electrode support contribution to plasmonic electrocatalysis is missing. Herein, we systematically investigated the effect of the supporting electrode material on the observed photocatalytic enhancement by comparing photoelectrocatalytic properties of AuNPs supported on highly oriented pyrolytic graphite (HOPG) and on indium tin oxide (ITO) electrodes using electrocatalytic benzyl alcohol (BnOH) oxidation as a model system. Upon illumination, only ~(3 ± 1)% enhancement in catalytic current was recorded on the AuNP/ITO electrodes in contrast to ~(42 ± 6)% enhancement on AuNP/HOPG electrodes. Our results showed that the local heating due to light absorption by the electrode material itself independent of localized surface plasmon effects is the primary source of the observed significant photo-induced enhancement on the HOPG electrodes in comparison to the ITO electrodes. Moreover, we demonstrated that an increased interfacial charge transfer at elevated temperatures, and not faster substrate diffusion is the main source of the enhancement. This work highlights the importance of systematic evaluation of contributions of all parts, even if they are catalytically inert, to the light-induced facilitation of catalytic reactions in plasmonic systems.

NANO ◽  
2020 ◽  
Vol 15 (04) ◽  
pp. 2050043
Author(s):  
Huayu Zhou ◽  
Jingjing Wang ◽  
Qiong Yang ◽  
Menglei Chen ◽  
Changsheng Song ◽  
...  

We report a one-step electrochemical deposition technique to prepare three-dimensional (3D) Ag hierarchical micro/nanostructured film consisting of well-crystallized Ag nanosheets grown on an indium tin oxide (ITO) conductive substrate. The Ag hierarchical micro/nanostructures were fabricated in the mixed solution of AgNO3 and sodium citrate in a constant current system at room temperature. Through reduction of Ag[Formula: see text] electrodeposited on the surface of ITO substrate, nanoparticles were grown to form nanosheets which further combined into 3D sphere-like microstructures. The 3D Ag micro/nanostructures have many sharp edges and nanoscale gaps which can give rise to good Raman-enhanced effect. Due to localized surface plasmon resonance (LSPR) effects, these special Ag micro/nanostructures exhibited good Raman-enhanced performance. Using Rhodamine 6G (R6G) molecules as probe molecule, we studied the influence of excitation wavelength on Raman enhancement. The results showed that the 532[Formula: see text]nm excitation wavelength is the best to obtain the strongest Raman signal and to reduce the influence of other impurity peaks. Using the as-synthesized Ag hierarchical micro/nanostructures, we can detect the 10[Formula: see text][Formula: see text]mol/L R6G aqueous solution, exhibiting great Raman-enhanced effect.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Amardeep Bharti ◽  
Keun Hwa Chae ◽  
Navdeep Goyal

AbstractPlasmonic nanostructures are of immense interest of research due to its widespread applications in microelectronics, photonics, and biotechnology, because of its size and shape-dependent localized surface plasmon resonance response. The great efforts have been constructed by physicists, chemists, and material scientists to deliver optimized reaction protocol to tailor the size and shape of nanostructures. Real-time characterization emerges out as a versatile tool in perspective to the optimization of synthesis parameters. Moreover, in the past decades, radiation-induced reduction of metallic-salt to nanoparticles dominates over the conventional direct chemical reduction process which overcomes the production of secondary products and yields ultra-high quality and pure nanostructures. Here we show, the real-time/in-situ synthesis and detection of plasmonic (Au andAg) nanoparticles using single synchrotron monochromatic 6.7 keV X-rays based Nano-Tomography beamline. The real-time X-ray nano-tomography of plasmonic nanostructures has been first-time successfully achieved at such a low-energy that would be leading to the possibility of these experiments at laboratory-based sources. In-situ optical imaging confirms the radiolysis of water molecule resulting in the production of $$e_{aq}^-,\,OH^\bullet ,$$ e aq - , O H ∙ , and $$O_2^-$$ O 2 - under X-ray irradiation. The obtained particle-size and size-distribution by X-ray tomography are in good agreement to TEM results. The effect of different chemical environment media on the particle-size has also been studied. This work provides the protocol to precisely control the size of nanostructures and to synthesize the ultrahigh-purity grade monodisperse nanoparticles that would definitely enhance the phase-contrast in cancer bio-imaging and plasmonic photovoltaic application.


Nanoscale ◽  
2020 ◽  
Vol 12 (48) ◽  
pp. 24357-24361
Author(s):  
Bingbing Han ◽  
Sila Jin ◽  
Qi Chu ◽  
Yang Jin ◽  
Xiangxin Xue ◽  
...  

The localized surface plasmon resonance (LSPR) of Ag/indium tin oxide (ITO)@polystyrene (PS) in the visible-NIR region was dependent on the tuning of the carrier density caused by adjusting the thickness of the ITO layer.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Y. Premkumar Singh ◽  
Amit Jain ◽  
Avinashi Kapoor

The paper investigates the light incoupling into c-Si solar cells due to the excitation of localized surface plasmon resonances in periodic metallic nanoparticles by finite-difference time-domain (FDTD) technique. A significant enhancement of AM1.5G solar radiation transmission has been demonstrated by depositing nanoparticles of various metals on the upper surface of a semi-infinite Si substrate. Plasmonic nanostructures located close to the cell surface can scatter incident light efficiently into the cell. Al nanoparticles were found to be superior to Ag, Cu, and Au nanoparticles due to the improved transmission of light over almost the entire solar spectrum and, thus, can be a potential low-cost plasmonic metal for large-scale implementation of solar cells.


RSC Advances ◽  
2017 ◽  
Vol 7 (75) ◽  
pp. 47643-47653 ◽  
Author(s):  
Rana Arslan Afzal ◽  
Ka-Young Park ◽  
Sung-Hwa Cho ◽  
Nam-In Kim ◽  
Sung Ryul Choi ◽  
...  

Bi0.6Ca0.4FeO3 demonstrates potential as an oxygen electrode material (for oxygen evolution and reduction reactions) for operation at room and elevated temperatures.


2021 ◽  
Author(s):  
Mahfujur Rahaman ◽  
Muhammad Aslam ◽  
Lu He ◽  
Teresa Madeira ◽  
Dietrich Zahn

Abstract InSe is one of the most promising two-dimensional (2D) materials for electronic and optoelectronic applications because of its favourable bandgap and superior electron mobility compared to other layered semiconductors. However, due to the polar nature of InSe, Fröhlich interaction plays an important role in electrical transport, which becomes more significant in reduced dimensionality. Until now, it is not yet known how the dimensionality influences the strength and nature of the Fröhlich polaronic effect in InSe. Here, we report on layer dependent anomalous Fröhlich interaction in InSe from bulk to monolayer with the aid of plasmonic hot electron doping. When excited near the localized surface plasmon resonance, plasmonic nanostructures produce highly energetic electrons (known as hot electrons), which can be captured by a semiconductor such as InSe at the interface. These electrons then couple to the polar optical phonons via the Fröhlich interaction in InSe. With the aid of the strong plasmonic field, the Fröhlich interaction enabling us to monitor the polar phonons in conventional Raman measurements. We prepared nanostructures with three different metals (Ag, Au, and Al) using nanosphere lithography on InSe to study the hot electron doping effect by means of Raman spectroscopy. A finite element method simulation was used to understand the coupling between the plasmonic nanostructures and InSe. We observed that the intensity of polar LO phonon modes initially increases gradually with decreasing layer number and then drops drastically from 7L to 6L, i.e. at the thickness where the transition from quasi-direct to indirect bandgap occurs at room temperature. Additionally, a gradual decrease of intensity of the polar modes with decreasing layer thickness below this transition point is observed, which is due to the increasing indirect bandgap nature of InSe suggesting reduced Fröhlich coupling. Our results shed light on fundamental understanding of Fröhlich interaction in InSe, which is crucial for electronic and optoelectronic applications of this promising 2D material.


2016 ◽  
Vol 1140 ◽  
pp. 115-122 ◽  
Author(s):  
Amer Almohallami ◽  
Michael Rusch ◽  
Milan Vucetic ◽  
Anas Bouguecha ◽  
Markus Bambach ◽  
...  

Due to the limitations of other processes in joining different types of material, mechanical joining methods can be alternatively used. Joining by upset bulging can be employed for joining tubes with other structures such as sheets, plates, tubes or profiles as well as for joining different materials. In spite of successful industrial applications of this joining process, material damage is still a challenge. This damage affects the resistance of the created joint to service loads. Thus, in this paper, a local heating is studied, which aims at avoiding pre-damage or failure of the joint. A parametric FE model is developed to analyse the influence of local heating on the bulging process. It is found that the process window set by the bulge length suitable for joining is widened, but only to a minor extent. The marginal influence of local heating on the bulge geometry allows designing the process in the same way as room temperature processes. Metallographic investigations confirm the damage-free bulging of tubes by forming at elevated temperatures. Another important result is that tubes can be equipped with predefined bulge zones by local heating zones to 700 °C for 15 seconds for example. This enables bulging of tubes during joining by applying an axial load only, without using tools to define the location of the bulge or its length, thus enabling joining operations with limited access.


Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 619 ◽  
Author(s):  
ChaeWon Mun ◽  
Vo Thi Nhat Linh ◽  
Jung-Dae Kwon ◽  
Ho Sang Jung ◽  
Dong-Ho Kim ◽  
...  

This paper reports a highly sensitive and selective surface-enhanced Raman spectroscopy (SERS) sensing platform. We used a simple fabrication method to generate plasmonic hotspots through a direct maskless plasma etching of a polymer surface and the surface tension-driven assembly of high aspect ratio Ag/polymer nanopillars. These collapsed plasmonic nanopillars produced an enhanced near-field interaction via coupled localized surface plasmon resonance. The high density of the small nanogaps yielded a high plasmonic detection performance, with an average SERS enhancement factor of 1.5 × 107. More importantly, we demonstrated that the encapsulation of plasmonic nanostructures within nanofiltration membranes allowed the selective filtration of small molecules based on the degree of membrane swelling in organic solvents and molecular size. Nanofiltration membrane-encapsulated SERS substrates do not require pretreatments. Therefore, they provide a simple and fast detection of toxic molecules using portable Raman spectroscopy.


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