scholarly journals Surface plasmon mediates the visible light–responsive lithium–oxygen battery with Au nanoparticles on defective carbon nitride

2021 ◽  
Vol 118 (17) ◽  
pp. e2024619118
Author(s):  
Zhuo Zhu ◽  
Youxuan Ni ◽  
Qingliang Lv ◽  
Jiarun Geng ◽  
Wei Xie ◽  
...  
Keyword(s):  
Visible Light ◽  
Rate Capability ◽  
Bifunctional Catalyst ◽  
Discharge Voltage ◽  
Hot Electrons ◽  
Au Nanoparticle ◽  
Plasmonic Enhancement ◽  
Charge Voltage ◽  
Au Nps ◽  
Nitrogen Vacancies

Aprotic lithium-oxygen (Li-O2) batteries have gained extensive interest in the past decade, but are plagued by slow reaction kinetics and induced large-voltage hysteresis. Herein, we use a plasmonic heterojunction of Au nanoparticle (NP)–decorated C3N4 with nitrogen vacancies (Au/NV-C3N4) as a bifunctional catalyst to promote oxygen cathode reactions of the visible light–responsive Li-O2 battery. The nitrogen vacancies on NV-C3N4 can adsorb and activate O2 molecules, which are subsequently converted to Li2O2 as the discharge product by photogenerated hot electrons from plasmonic Au NPs. While charging, the holes on Au NPs drive the reverse decomposition of Li2O2 with a reduced applied voltage. The discharge voltage of the Li-O2 battery with Au/NV-C3N4 is significantly raised to 3.16 V under illumination, exceeding its equilibrium voltage, and the decreased charge voltage of 3.26 V has good rate capability and cycle stability. This is ascribed to the plasmonic hot electrons on Au NPs pumped from the conduction bands of NV-C3N4 and the prolonged carrier life span of Au/NV-C3N4. This work highlights the vital role of plasmonic enhancement and sheds light on the design of semiconductors for visible light–mediated Li-O2 batteries and beyond.

Tuning the Photocatalytic Performance of Plasmonic Nanocomposites (ZnO/Aux) Driven in Visible Light

2019 ◽  
Vol 8 (1) ◽  
pp. 56-61
Author(s):  
Aneeya K. Samantara ◽  
Debasrita Dash ◽  
Dipti L. Bhuyan ◽  
Namita Dalai ◽  
Bijayalaxmi Jena
Keyword(s):  
Electron Transfer ◽  
Photocatalytic Activity ◽  
Visible Light ◽  
Transfer Rate ◽  
Photocatalytic Performance ◽  
Light Exposure ◽  
Au Nanoparticle ◽  
Electron Transfer Rate ◽  
Au Nps ◽  
Zno Nanostructure

: In this article, we explored the possibility of controlling the reactivity of ZnO nanostructures by modifying its surface with gold nanoparticles (Au NPs). By varying the concentration of Au with different wt% (x = 0.01, 0.05, 0.08, 1 and 2), we have synthesized a series of (ZnO/Aux) nanocomposites (NCs). A thorough investigation of the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface has been carried out. It was observed that ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity among all concentrations of Au on the ZnO surface, which degrades the dye concentration within 2 minutes of visible light exposure. It was further revealed that with an increase in the size of plasmonic nanoparticles beyond 0.08%, the accessible surface area of the Au nanoparticle decreases. The photon absorption capacity of Au nanoparticle decreases beyond 0.08% resulting in a decrease in electron transfer rate from Au to ZnO and a decrease of photocatalytic activity. Background: Due to the industrialization process, most of the toxic materials go into the water bodies, affecting the water and our ecological system. The conventional techniques to remove dyes are expensive and inefficient. Recently, heterogeneous semiconductor materials like TiO2 and ZnO have been regarded as potential candidates for the removal of dye from the water system. Objective: To investigate the photocatalytic performance of different wt% of Au NPs on ZnO nanosurface and the effect of the size of Au NPs for photocatalytic performance in the degradation process. Methods: A facile microwave method has been adopted for the synthesis of ZnO nanostructure followed by a reduction of gold salt in the presence of ZnO nanostructure to form the composite. Results: ZnO/Au0.08 nanocomposite showed the highest photocatalytic activity which degrades the dye concentration within 2 minutes of visible light exposure. The schematic mechanism of electron transfer rate was discussed. Conclusion: Raspberry shaped ZnO nanoparticles modified with different percentages of Au NPs showed good photocatalytic behavior in the degradation of dye molecules. The synergetic effect of unique morphology of ZnO and well anchored Au nanostructures plays a crucial role.

Au Nanoparticle Enhancement of Plasma-Driven Methane Conversion into Higher Order Hydrocarbons via Hot Electrons

2020 ◽  
Vol 3 (12) ◽  
pp. 12388-12393
Author(s):  
Bofan Zhao ◽  
Indu Aravind ◽  
Sisi Yang ◽  
Yu Wang ◽  
Ruoxi Li ◽  
...  
Keyword(s):  
Methane Conversion ◽  
Higher Order ◽  
Hot Electrons ◽  
Au Nanoparticle

scholarly journals Combination of chemotherapy and Au-nanoparticle photothermy in the visible light to tackle doxorubicin resistance in cancer cells

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Pedro Pedrosa ◽  
Rita Mendes ◽  
Rita Cabral ◽  
Luísa M. D. R. S. Martins ◽  
Pedro V. Baptista ◽  
...  
Keyword(s):  
Visible Light ◽  
Cancer Cells ◽  
Au Nanoparticle ◽  
Doxorubicin Resistance

scholarly journals Effect of Conditions of Sol-Gel Synthesis and Post-Synthetic Treatment on Photoelectrochemical and Electro-Catalytic Properties of Titanium Oxide Nanostructures and Tio2-Au Nanocomposites

2021 ◽  
Vol 57 (4) ◽  
pp. 1-14
Author(s):  
N.I. Romanovska ◽  
◽  
P.A. Manorik ◽  
V.S. Vorobets ◽  
G.Ya. Kolbasov ◽  
...  
Keyword(s):  
Visible Light ◽  
Au Nanoparticles ◽  
Sol Gel ◽  
Au Nanoparticle ◽  
Chemical Compositions ◽  
High Catalytic Activity ◽  
Electron Microscopies ◽  
Treatment Conditions ◽  
Carboxylate Groups ◽  
Tio2 Nanostructures

Carbon-doped mesoporous TiO2 nanostructures and TiO2-Au nanocomposites with stabilized Au nanoparticles have been synthesized by the sol-gel template method and characterized by X-ray diffraction, scanning and transmission electron microscopies, Fourier-transform infrared spectroscopy, N2 adsorption/desorption, ultraviolet-visible spectroscopy, and photoelectrochemical current spectroscopy. The synthesis hydrothermal treatment conditions affected the particle size, electronic structure, morphology, phase, and chemical compositions, as well as the texture of the synthesized materials. The TiO2 and TiO2-Au based electrodes were light-sensitive in a wavelength range of 250–412 nm and were distinguished by a high catalytic activity during oxygen electroreduction. The presence of -ol and carboxylate groups in the amorphous phase is the main factor affecting the photosensitivity of TiO2 nanostructures to visible light and an increase in their photoactivity during the decomposition of methylene blue upon irradiation with ultraviolet and visible light relative to pure anatase. The higher photosensitivity and photoactivity of TiO2-Au nanocomposites compared with those of the corresponding starting TiO2 is due to the synergistic effect of Au nanoparticles and interstitial Ti-O-C groups, which depends on the Au nanoparticle content of the composite and on the mesopore size.

Hot-Electrons Mediated Efficient Visible-Light Photocatalysis of Hierarchical Black Au-TiO2Nanorod Arrays on Flexible Substrate

2016 ◽  
Vol 3 (22) ◽  
pp. 1600588 ◽  
Author(s):  
Huimin Shi ◽  
Xuejiao Wang ◽  
Mengjie Zheng ◽  
Xing Wu ◽  
Yiqin Chen ◽  
...  
Keyword(s):  
Visible Light ◽  
Flexible Substrate ◽  
Hot Electrons ◽  
Visible Light Photocatalysis

Visible-Light-Driven Production of Poly(α-terthiophene)-Au Nanoparticle Functional Hybrid Material

ChemNanoMat ◽  
2015 ◽  
Vol 1 (8) ◽  
pp. 586-592 ◽  
Author(s):  
Raj Kumar Bera ◽  
Prasenjit Bhunia ◽  
Sukanta Chakrabartty ◽  
C. Retna Raj
Keyword(s):  
Visible Light ◽  
Hybrid Material ◽  
Au Nanoparticle ◽  
Visible Light Driven

scholarly journals TiO2 and Au-TiO2 Nanomaterials for Rapid Photocatalytic Degradation of Antibiotic Residues in Aquaculture Wastewater

Materials ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2434 ◽  
Author(s):  
Tho Chau Minh Vinh Do ◽  
Duy Quoc Nguyen ◽  
Kien Trung Nguyen ◽  
Phuoc Huu Le
Keyword(s):  
Photocatalytic Activity ◽  
Photocatalytic Degradation ◽  
Synergistic Effects ◽  
Chemical Reduction ◽  
Anatase Phase ◽  
Au Nanoparticle ◽  
Nanotube Arrays ◽  
Antibiotic Residues ◽  
Au Nps ◽  
Aquaculture Wastewater

Antibiotic residues in aquaculture wastewater are considered as an emerging environmental problem, as they are not efficiently removed in wastewater treatment plants. To address this issue, we fabricated TiO2 nanotube arrays (TNAs), TiO2 nanowires on nanotube arrays (TNWs/TNAs), Au nanoparticle (NP)-decorated-TNAs, and TNWs/TNAs, which were applied for assessing the photocatalytic degradation of eight antibiotics, simultaneously. The TNAs and TNWs/TNAs were synthesized by anodization using an aqueous NH4F/ethylene glycol solution. Au NPs were synthesized by chemical reduction method, and used to decorate on TNAs and TNWs/TNAs. All the TiO2 nanostructures exhibited anatase phase and well-defined morphology. The photocatalytic performance of TNAs, TNWs/TNAs, Au-TNAs and Au-TNWs/TNAs was studied by monitoring the degradation of amoxicillin, ampicillin, doxycycline, oxytetracycline, lincomycin, vancomycin, sulfamethazine, and sulfamethoxazole under ultraviolet (UV)-visible (VIS), or VIS illumination by LC-MS/MS method. All the four kinds of nanomaterials degraded the antibiotics effectively and rapidly, in which most antibiotics were removed completely after 20 min treatment. The Au-TNWs/TNAs exhibited the highest photocatalytic activity in degradation of the eight antibiotics. For example, reaction rate constants of Au-TNWs/TNAs for degradation of lincomycin reached 0.26 min−1 and 0.096 min−1 under UV-VIS and VIS irradiation, respectively; and they were even higher for the other antibiotics. The excellent photocatalytic activity of Au-TNWs/TNAs was attributed to the synergistic effects of: (1) The larger surface area of TNWs/TNAs as compared to TNAs, and (2) surface plasmonic effect in Au NPs to enhance the visible light harvesting.

scholarly journals Hot Electrons, Hot Holes, or Both? Tandem Synthesis of Imines Driven by the Plasmonic Excitation in Au/CeO2 Nanorods

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1530
Author(s):  
Ivo F. Teixeira ◽  
Mauricio S. Homsi ◽  
Rafael S. Geonmonond ◽  
Guilherme F. S. R. Rocha ◽  
Yung-Kang Peng ◽  
...  
Keyword(s):  
Benzyl Alcohol ◽  
Oxidative Coupling ◽  
Reaction Pathway ◽  
Synergistic Effects ◽  
Chemical Conversion ◽  
Hot Electrons ◽  
Localized Surface Plasmon ◽  
Au Nps ◽  
Surface Vacancy ◽  
Photocatalytic Reactions

Solar-to-chemical conversion via photocatalysis is of paramount importance for a sustainable future. Thus, investigating the synergistic effects promoted by light in photocatalytic reactions is crucial. The tandem oxidative coupling of alcohols and amines is an attractive route to synthesize imines. Here, we unravel the performance and underlying reaction pathway in the visible-light-driven tandem oxidative coupling of benzyl alcohol and aniline employing Au/CeO2 nanorods as catalysts. We propose an alternative reaction pathway for this transformation that leads to improved efficiencies relative to individual CeO2 nanorods, in which the localized surface plasmon resonance (LSPR) excitation in Au nanoparticles (NPs) plays an important role. Our data suggests a synergism between the hot electrons and holes generated from the LSPR excitation in Au NPs. While the oxygen vacancies in CeO2 nanorods trap the hot electrons and facilitate their transfer to adsorbed O2 at surface vacancy sites, the hot holes in the Au NPs facilitate the α-H abstraction from the adsorbed benzyl alcohol, evolving into benzaldehyde, which then couples with aniline in the next step to yield the corresponding imine. Finally, cerium-coordinated superoxide species abstract hydrogen from the Au surface, regenerating the catalyst surface.

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