共查询到20条相似文献,搜索用时 36 毫秒
1.
Yuying Gao Wei Nie Qianhong Zhu Xun Wang Shengyang Wang Prof. Fengtao Fan Prof. Can Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(41):18375-18380
Controlling the interaction of polarization light with an asymmetric nanostructure such as a metal/semiconductor heterostructure provides opportunities for tuning surface plasmon excitation and near-field spatial distribution. However, light polarization effects on interfacial charge transport and the photocatalysis of plasmonic metal/semiconductor photocatalysts are unclear. Herein, we reveal the polarization dependence of plasmonic charge separation and spatial distribution in Au/TiO2 nanoparticles under 45° incident light illumination at the single-particle level using a combination of photon-irradiated Kelvin probe force microscopy (KPFM) and electromagnetic field simulation. We quantitatively uncover the relationship between the local charge density and polarization angle by investigating the polarization-dependent surface photovoltage (SPV). The plasmon-induced photocatalytic activity is enhanced when the polarization direction is perpendicular to the Au/TiO2 interface. 相似文献
2.
Visible‐Light‐Induced Electron Transport from Small to Large Nanoparticles in Bimodal Gold Nanoparticle‐Loaded Titanium(IV) Oxide 下载免费PDF全文
Dr. Shin‐ichi Naya Tadahiro Niwa Takahiro Kume Prof. Dr. Hiroaki Tada 《Angewandte Chemie (International ed. in English)》2014,53(28):7305-7309
A key to realizing the sustainable society is to develop highly active photocatalysts for selective organic synthesis effectively using sunlight as the energy source. Recently, metal‐oxide‐supported gold nanoparticles (NPs) have emerged as a new type of visible‐light photocatalysts driven by the excitation of localized surface plasmon resonance of Au NPs. Here we show that visible‐light irradiation (λ>430 nm) of TiO2‐supported Au NPs with a bimodal size distribution (BM‐Au/TiO2) gives rise to the long‐range (>40 nm) electron transport from about 14 small (ca. 2 nm) Au NPs to one large (ca. 9 nm) Au NP through the conduction band of TiO2. As a result of the enhancement of charge separation, BM‐Au/TiO2 exhibits a high level of visible‐light activity for the one‐step synthesis of azobenzenes from nitrobenzenes at 25 °C with a yield greater than 95 % and a selectivity greater than 99 %, whereas unimodal Au/TiO2 (UM‐Au/TiO2) is photocatalytically inactive. 相似文献
3.
Probing Long‐Lived Plasmonic‐Generated Charges in TiO2/Au by High‐Resolution X‐ray Absorption Spectroscopy 下载免费PDF全文
Dr. Lucia Amidani Dr. Alberto Naldoni Dr. Marco Malvestuto Dr. Marcello Marelli Dr. Pieter Glatzel Dr. Vladimiro Dal Santo Prof. Federico Boscherini 《Angewandte Chemie (International ed. in English)》2015,54(18):5413-5416
4.
Weerasak Chomkitichai Hathaithip Ninsonti Akira Baba Sukon Phanichphant Kazunari Shinbo Keizo Kato Futao Kaneko 《Surface and interface analysis : SIA》2014,46(9):607-612
We demonstrate the multiple plasmonic effect on the photocurrent properties of photoanodes containing Ag or Au nanoparticles (NPs) loaded onto titanium dioxide film (Ag–TiO2 or Au–TiO2) on Au grating surfaces. Ag–TiO2 or Au–TiO2 nanocomposite particles are prepared by a flame spray pyrolysis route. The structures and morphologies of the prepared products are characterized by high‐resolution transmission electron microscopy. The Ag–TiO2 or Au–TiO2 composite NPs are deposited by spin coating onto the Au grating surfaces. The photoanode electrode is a layered structure of blu‐ray disc‐recordable grating substrate/Au/Ag (or Au)–TiO2/dye/electrolyte/indium‐tin oxide. The plasmonic effect is induced when Ag or Au NPs are located within the propagating surface plasmon (SP) field on the Au grating surface. The short‐circuit photocurrent is increased by exciting the grating‐coupled propagating SP on the Au gratings and is further enhanced by positioning the Ag or Au NPs within the grating‐coupled SP field. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
5.
Integration of Plasmonic Effects and Schottky Junctions into Metal–Organic Framework Composites: Steering Charge Flow for Enhanced Visible‐Light Photocatalysis 下载免费PDF全文
Juan‐Ding Xiao Dr. Lili Han Prof. Dr. Jun Luo Prof. Dr. Shu‐Hong Yu Prof. Dr. Hai‐Long Jiang 《Angewandte Chemie (International ed. in English)》2018,57(4):1103-1107
A wide range of light absorption and rapid electron–hole separation are desired for efficient photocatalysis. Herein, on the basis of a semiconductor‐like metal–organic framework (MOF), a Pt@MOF/Au catalyst with two types of metal–MOF interfaces integrates the surface plasmon resonance excitation of Au nanorods with a Pt‐MOF Schottky junction, which not only extends the light absorption of the MOF from the UV to the visible region but also greatly accelerates charge transfer. The spatial separation of Pt and Au particles by the MOF further steers the formation of charge flow and expedites the charge migration. As a result, the Pt@MOF/Au presents an exceptionally high photocatalytic H2 production rate by water splitting under visible light irradiation, far superior to Pt/MOF/Au, MOF/Au and other counterparts with similar Pt or Au contents, highlighting the important role of each component and the Pt location in the catalyst. 相似文献
6.
Oxidation Ability of Plasmon‐Induced Charge Separation Evaluated on the Basis of Surface Hydroxylation of Gold Nanoparticles 下载免费PDF全文
Dr. Hiroyasu Nishi Prof. Tetsu Tatsuma 《Angewandte Chemie (International ed. in English)》2016,55(36):10771-10775
The oxidation ability of plasmonic photocatalysts, which has its origins in plasmon‐induced charge separation and has not yet been studied quantitatively and systematically, is important for designing practical photocatalytic systems. Oxidation ability was investigated on the basis of surface hydroxylation of Au nanoparticles on TiO2 at various irradiation wavelengths and electrolyte pH values. The reaction proceeds only when the sum of the flat band potential of TiO2 and the irradiated photon energy is close to, or more positive than, the theoretical potential for the reaction. 相似文献
7.
Full Solution‐Processed Synthesis and Mechanisms of a Recyclable and Bifunctional Au/ZnO Plasmonic Platform for Enhanced UV/Vis Photocatalysis and Optical Properties 下载免费PDF全文
Prof. Da‐Ren Hang Sk Emdadul Islam Prof. Chun‐Hu Chen Krishna Hari Sharma 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):14950-14961
The synthesis of noble metal/semiconductor hybrid nanostructures for enhanced catalytic or superior optical properties has attracted a lot of attention in recent years. In this study, a facile and all‐solution‐processed synthetic route was employed to demonstrate an Au/ZnO platform with plasmonic‐enhanced UV/Vis catalytic properties while retaining strengthened luminescent properties. The visible‐light response of photocatalysis is supported by localized surface plasmon resonance (LSPR) excitations while the enhanced performance under UV is aided by charge separation and strong absorption. The enhancement in optical properties is mainly due to local field enhancement effect and coupling between exciton and LSPR. Luminescent characteristics are investigated and discussed in detail. Recyclability tests showed that the Au/ZnO substrate is reusable by cleaning and has a long shelf life. Our result suggests that plasmonic enhancement of photocatalytic performance is not necessarily a trade‐off for enhanced near‐band‐edge emission in Au/ZnO. This approach may give rise to a new class of versatile platforms for use in novel multifunctional and integrated devices. 相似文献
8.
Prolonged Hot Electron Dynamics in Plasmonic‐Metal/Semiconductor Heterostructures with Implications for Solar Photocatalysis 下载免费PDF全文
Joseph S. DuChene Brendan C. Sweeny Dr. Aaron C. Johnston‐Peck Dr. Dong Su Dr. Eric A. Stach Prof. Dr. Wei David Wei 《Angewandte Chemie (International ed. in English)》2014,53(30):7887-7891
Ideal solar‐to‐fuel photocatalysts must effectively harvest sunlight to generate significant quantities of long‐lived charge carriers necessary for chemical reactions. Here we demonstrate the merits of augmenting traditional photoelectrochemical cells with plasmonic nanoparticles to satisfy these daunting photocatalytic requirements. Electrochemical techniques were employed to elucidate the mechanics of plasmon‐mediated electron transfer within Au/TiO2 heterostructures under visible‐light (λ>515 nm) irradiation in solution. Significantly, we discovered that these transferred electrons displayed excited‐state lifetimes two orders of magnitude longer than those of electrons photogenerated directly within TiO2 via UV excitation. These long‐lived electrons further enable visible‐light‐driven H2 evolution from water, heralding a new photocatalytic paradigm for solar energy conversion. 相似文献
9.
Dr. Haiyan Li Wenbo Lu Jingqi Tian Yonglan Luo Prof. Abdullah M. Asiri Abdulrahman O. Al‐Youbi Prof. Xuping Sun 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(27):8508-8514
Nanocomposites of Ag/TiO2 nanowires with enhanced photoelectrochemical performance have been prepared by a facile solvothermal synthesis of TiO2 nanowires and subsequent photoreduction of Ag+ ions to Ag nanoparticles (AgNPs) on the TiO2 nanowires. The as‐prepared nanocomposites exhibited significantly improved cathodic photocurrent responses under visible‐light illumination, which is attributed to the local electric field enhancement of plasmon resonance effect near the TiO2 surface rather than by the direct transfer of charge between the two materials. The visible‐light‐driven photocatalytic performance of these nanocomposites in the degradation of methylene blue dye was also studied, and the observed improvement in photocatalytic activity is associated with the extended light absorption range and efficient charge separation due to surface plasmon resonance effect of AgNPs. 相似文献
10.
Plasmon‐Assisted Water Splitting Using Two Sides of the Same SrTiO3 Single‐Crystal Substrate: Conversion of Visible Light to Chemical Energy 下载免费PDF全文
Yuqing Zhong Prof. Kosei Ueno Yuko Mori Dr. Xu Shi Dr. Tomoya Oshikiri Prof. Kei Murakoshi Prof. Haruo Inoue Prof. Hiroaki Misawa 《Angewandte Chemie (International ed. in English)》2014,53(39):10350-10354
A plasmon‐induced water splitting system that operates under irradiation by visible light was successfully developed; the system is based on the use of both sides of the same strontium titanate (SrTiO3) single‐crystal substrate. The water splitting system contains two solution chambers to separate hydrogen (H2) and oxygen (O2). To promote water splitting, a chemical bias was applied by regulating the pH values of the chambers. The quantity of H2 evolved from the surface of platinum, which was used as a reduction co‐catalyst, was twice the quantity of O2 evolved from an Au‐nanostructured surface. Thus, the stoichiometric evolution of H2 and O2 was clearly demonstrated. The hydrogen‐evolution action spectrum closely corresponds to the plasmon resonance spectrum, indicating that the plasmon‐induced charge separation at the Au/SrTiO3 interface promotes water oxidation and the subsequent reduction of a proton on the backside of the SrTiO3 substrate. The chemical bias is significantly reduced by plasmonic effects, which indicates the possibility of constructing an artificial photosynthesis system with low energy consumption. 相似文献
11.
Shuai He Jiawei Huang Justin L. Goodsell Alexander Angerhofer Wei David Wei 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(18):6099-6102
Plasmon‐mediated carrier transfer (PMCT) at metal–semiconductor heterojunctions has been extensively exploited to drive photochemical reactions, offering intriguing opportunities for solar photocatalysis. However, to date, most studies have been conducted using noble metals. Inexpensive materials capable of generating and transferring hot carriers for photocatalysis via PMCT have been rarely explored. Here, we demonstrate that the plasmon excitation of nickel induces the transfer of both hot electrons and holes from Ni to TiO2 in a rationally designed Ni–TiO2 heterostructure. Furthermore, it is discovered that the transferred hot electrons either occupy oxygen vacancies (VO) or produce Ti3+ on TiO2, while the transferred hot holes are located on surface oxygens at TiO2. Moreover, the transferred hot electrons are identified to play a primary role in driving the degradation of methylene blue (MB). Taken together, our results validate Ni as a promising low‐cost plasmonic material for prompting visible‐light photochemical reactions. 相似文献
12.
Constructing Ordered Three‐Dimensional TiO2 Channels for Enhanced Visible‐Light Photocatalytic Performance in CO2 Conversion Induced by Au Nanoparticles 下载免费PDF全文
Dr. Hairong Xue Prof. Dr. Tao Wang Hao Gong Hu Guo Xiaoli Fan Bin Gao Yaya Feng Prof. Dr. Xianguang Meng Prof. Dr. Xianli Huang Prof. Dr. Jianping He 《化学:亚洲杂志》2018,13(5):577-583
As a typical photocatalyst for CO2 reduction, practical applications of TiO2 still suffer from low photocatalytic efficiency and limited visible‐light absorption. Herein, a novel Au‐nanoparticle (NP)‐decorated ordered mesoporous TiO2 (OMT) composite (OMT‐Au) was successfully fabricated, in which Au NPs were uniformly dispersed on the OMT. Due to the surface plasmon resonance (SPR) effect derived from the excited Au NPs, the TiO2 shows high photocatalytic performance for CO2 reduction under visible light. The ordered mesoporous TiO2 exhibits superior material and structure, with a high surface area that offers more catalytically active sites. More importantly, the three‐dimensional transport channels ensure the smooth flow of gas molecules, highly efficient CO2 adsorption, and the fast and steady transmission of hot electrons excited from the Au NPs, which lead to a further improvement in the photocatalytic performance. These results highlight the possibility of improving the photocatalysis for CO2 reduction under visible light by constructing OMT‐based Au‐SPR‐induced photocatalysts. 相似文献
13.
Gold‐Nanoparticle‐Loaded Carbonate‐Modified Titanium(IV) Oxide Surface: Visible‐Light‐Driven Formation of Hydrogen Peroxide from Oxygen 下载免费PDF全文
Miwako Teranishi Riyoko Hoshino Dr. Shin‐ichi Naya Prof. Dr. Hiroaki Tada 《Angewandte Chemie (International ed. in English)》2016,55(41):12773-12777
Gold nanoparticle‐loaded rutile TiO2 with a bimodal size distribution around 10.6 nm and 2.3 nm (BM‐Au/TiO2) was prepared by the deposition precipitation and chemical reduction (DP‐CR) technique. Visible‐light irradiation (λ>430 nm) of the BM‐Au/TiO2 plasmonic photocatalyst yields 35 μm H2O2 in aerated pure water at irradiation time (tp)=1 h, and the H2O2 concentration increases to 640±60 μm by the addition of 4 % HCOOH as a sacrificing electron donor. Further, a carbonate‐modified surface BM‐Au/TiO2 (BM‐Au/TiO2‐CO32?) generates a millimolar level of H2O2 at tp=1 h with a quantum efficiency (Φ) of 5.4 % at λ=530 nm under the same conditions. The recycle experiments confirmed the stable performance of BM‐Au/TiO2. 相似文献
14.
Controlling the Selectivity of the Surface Plasmon Resonance Mediated Oxidation of p‐Aminothiophenol on Au Nanoparticles by Charge Transfer from UV‐excited TiO2 下载免费PDF全文
Dr. Jiale Wang Prof. Dr. Romulo A. Ando Prof. Dr. Pedro H. C. Camargo 《Angewandte Chemie (International ed. in English)》2015,54(23):6909-6912
Although catalytic processes mediated by surface plasmon resonance (SPR) excitation have emerged as a new frontier in catalysis, the selectivity of these processes remains poorly understood. Here, the selectivity of the SPR‐mediated oxidation of p‐aminothiophenol (PATP) employing Au NPs as catalysts was controlled by the choice of catalysts (Au or TiO2‐Au NPs) and by the modulation of the charge transfer from UV‐excited TiO2 to Au. When Au NPs were employed as catalyst, the SPR‐mediated oxidation of PATP yielded p,p‐dimercaptobenzene (DMAB). When TiO2‐Au NPs were employed as catalysts under both UV illumination and SPR excitation, p‐nitrophenol (PNTP) was formed from PATP in a single step. Interestingly, PNTP molecules were further reduced to DMAB after the UV illumination was removed. Our data show that control over charge‐transfer processes may play an important role to tune activity, product formation, and selectivity in SPR‐mediated catalytic processes. 相似文献
15.
By the photoexcitation of localized surface plasmon resonances of metal nanoparticles, one can generate reaction equivalents for driving redox reactions. We show that, in such cases, there is a chemical potential contributed by the plasmonic excitation. This chemical potential is a function of the concentration of light, as we determine from the light‐intensity‐dependent activity in the plasmon‐excitation‐driven reduction of CO2 on Au nanoparticles. Our finding allows the treatment of plasmonic excitation as a reagent in chemical reactions; the chemical potential of this reagent is tunable by the light intensity. 相似文献
16.
Ag/mesoporous black TiO2 nanotubes heterojunctions (Ag‐MBTHs) were fabricated through a surface hydrogenation, wet‐impregnation and photoreduction strategy. The as‐prepared Ag‐MBTHs possess a relatively high specific surface area of ≈85 m2 g?1 and an average pore size of ≈13.2 nm. The Ag‐MBTHs with a narrow band gap of ≈2.63 eV extend the photoresponse from UV to the visible‐light and near‐infrared (NIR) region. They exhibit excellent visible‐NIR‐driven photothermal catalytic and photocatalytic performance for complete conversion of nitro aromatic compounds (100 %) and mineralization of highly toxic phenol (100 %). The enhancement can be attributed to the mesoporous hollow structures increasing the light multi‐refraction, the Ti3+ in frameworks and the surface plasmon resonance (SPR) effect of plasmonic Ag nanoparticles favoring light‐harvesting and spatial separation of photogenerated electron–hole pairs, which is confirmed by transient fluorescence. The fabrication of this SPR‐enhanced visible‐NIR‐driven Ag‐MBTHs catalyst may provide new insights for designing other high‐performance heterojunctions as photocatalytic and photothermal catalytic nanomaterials. 相似文献
17.
Reem A. Karaballi Govinda Humagain Benjamin R. A. Fleischman Prof. Mita Dasog 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(10):3179-3182
Ceramic nanoparticles that exhibit a plasmonic response are promising next‐generation photonic materials. In this contribution, a solid‐state metathesis method has been reported for the synthesis of Group 4 nitride (TiN, ZrN, and HfN) nanocrystals. A high‐temperature (1000 °C) reaction between Group 4 metal oxide (TiO2, ZrO2, and HfO2) nanoparticles and magnesium nitride powder yielded nitride nanocrystals that were dispersible in water. A localized surface plasmonic resonance was observed in the near‐infrared region for TiN and in the visible region of light for ZrN and HfN nanocrystals. The frequency of the plasmon resonance was dependent on the refractive index of the solvent and the nanocrystal size. 相似文献
18.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(35):10483-10487
Underpotential photodeposition of Pb yields an ultrathin shell layer on the Au(111) surface of Au nanoparticle(NP)‐loaded TiO2 (Au/TiO2) with heteroepitaxial nanojunctions. The localized surface plasmon resonance of Au/TiO2 undergoes no damping with the Pb‐shell formation, and the Pb shell offers resistance to aerobic oxidation. Mesoporous films comprising the Au(core)–Pb(shell) NP‐loaded TiO2 and unmodified Au/TiO2 were formed on fluorine‐doped tin oxide (FTO) electrode. Using them as the photoanode, photoelectrochemical cells were fabricated, and the photocurrent was measured under illumination of simulated sunlight. The photocurrent for water splitting is dramatically enhanced by the Pb‐shell formation. The photoelectrochemical measurements of the hot‐electron lifetime and density functional theory calculations for model clusters indicate that the Pb‐shell effect originates from the charge separation enhancement. 相似文献
19.
Three‐Dimensional Ordered Assembly of Thin‐Shell Au/TiO2 Hollow Nanospheres for Enhanced Visible‐Light‐Driven Photocatalysis 下载免费PDF全文
Cao‐Thang Dinh Hoang Yen Prof. Freddy Kleitz Prof. Trong‐On Do 《Angewandte Chemie (International ed. in English)》2014,53(26):6618-6623
An Au/TiO2 nanostructure was constructed to obtain a highly efficient visible‐light‐driven photocatalyst. The design was based on a three‐dimensional ordered assembly of thin‐shell Au/TiO2 hollow nanospheres (Au/TiO2‐3 DHNSs). The designed photocatalysts exhibit not only a very high surface area but also photonic behavior and multiple light scattering, which significantly enhances visible‐light absorption. Thus Au/TiO2‐3 DHNSs exhibit a visible‐light‐driven photocatalytic activity that is several times higher than conventional Au/TiO2 nanopowders. 相似文献
20.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(6):1622-1626
As a remarkable class of plasmonic materials, two dimensional (2D) semiconductor compounds have attracted attention owing to their controlled manipulation of plasmon resonances in the visible light spectrum, which outperforms conventional noble metals. However, tuning of plasmonic resonances for 2D semiconductors remains challenging. Herein, we design a novel method to obtain amorphous molybdenum oxide (MoO3) nanosheets, in which it combines the oxidation of MoS2 and subsequent supercritical CO2‐treatment, which is a crucial step for the achievement of amorphous structure of MoO3. Upon illumination, hydrogen‐doped MoO3 exhibits tuned surface plasmon resonances in the visible and near‐IR regions. Moreover, a unique behavior of the amorphous MoO3 nanosheets has been found in an optical biosensing system; there is an optimum plasmon resonance after incubation with different BSA concentrations, suggesting a tunable plasmonic device in the near future. 相似文献