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Activation of silicon quantum dots for emission

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Chinese Physics B 2012年第9期21卷 295-300页

作者：黄伟其苗信建黄忠梅刘世荣秦朝建 Key Laboratory of Photoelectron Technology and Application Institute of Nanophotonic PhysicsGuizhou University State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese academy of Sciences

The emission of silicon quantum dots is weak when their surface is passivated well. Oxygen or nitrogen on the surface of silicon quantum dots can break the passivation to form localized electronic states in the band gap to generate active centers where stronger emission occurs. From this point of view, we can build up radiative matter for emission. Emissions of various wavelengths can be obtained by controlling the surface bonds of silicon quantum dots. Our experimental results demonstrate that annealing is important in the treatment of the activation, and stimulated emissions at about 600 and 700 nm take place on active silicon quantum dots.

关键词： activation for emission silicon quantum dots localized states

Preparation and Evaluation of silicon quantum dots-Bonded Silica Stationary Phase for Reversed-Phase Chromatography

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Journal of Analysis and Testing 2023年第1期7卷 8-15页

作者： Danni Wang Hui Li Hongdeng Qiu Jia Chen Laboratory on Pollution Monitoring and Control College of Chemistry and Chemical EngineeringXinjiang Normal UniversityUrumqi 830054China CAS Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China College of Chemistry and Chemical Engineering Gannan Normal UniversityGanzhou 341000China

In this paper,silicon quantum dots(SiQDs)with green fluorescence are synthesized by solvothermal reaction of 3-(2,3-epoxypropoxy)propyltrimethoxysilane(GPTMS)and ethylenediaminetetraacetic acid(EDTA),and then SiQDs are bonded to the surface of silica to obtain a new nano-on-micro stationary phase(SiO_(2)-SiQDs)for reversed-phase *** successful preparation of SiO_(2)-SiQDs stationary phase is demonstrated by a variety of characterizations,such as transmission electron microscopy,laser confocal microscopy,elemental analysis and Fourier infrared *** addition,the chromatographic performance of the prepared stationary phase is evaluated and it shows good separation performance for non-polar substances such as alkylbenzene,aniline and polycyclic aromatic hydrocarbons in reversed-phase liquid *** is also verified that the stationary phase has good methyl selectivity and shape *** interestingly,the separation of prednisolone and hydrocortisone isomers can also be achieved at a low ratio of organic solvents,indicating that this new stationary phase has a good application prospect in isomer separation.

关键词： silicon quantum dots Stationary phase Reversed-phase liquid chromatography Chromatographic separation Nano-on-micro

Bifunctional silicon quantum dots for Antibacterial Application and Highly Sensitive Detection of Tetracycline

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Journal of Analysis and Testing 2024年第2期8卷 218-227页

作者： Shuiqin Chai Yuting Chi Wanlin Sun Xinyu Pei Shuchen Pei Chengyu Sun Kang Luo Bo Yao College of Chemistry and Chemical Engineering Chongqing University of Science and TechnologyChongqing401331China People’s Hospital Affiliated to Chongqing Three Gorges Medical CollegeChongqing404037China

silicon quantum dots(SiQDs)with high water-soluble and favorable photostability were prepared by a one-step hydrothermal *** average diameter of SiQDs was 2.02 nm characterized by transmission electron *** was to be noted that the as-prepared SiQDs showed eff ective antibacterial activity,which was attributed to electrostatic interaction and the generation of reactive oxygen *** minimum inhibitory concentration of SiQDs against Escherichia coli and Staphylococcus aureus was 0.45 mg/mL and 0.38 mg/mL,***,based on the static quenching eff ect-induced fluorescence quenching mechanism,the SiQDs exhibited high sensitivity and selectivity for detecting tetracyclines(TC).A good linear relationship was obtained between the fluorescence intensity of SiQDs and the concentration of tetracycline(TC)in the range of 0–0.08μmol/L(R^(2)=0.9993)with a detection limit of 0.0176μmol/***,the TC content in the honey samples was determined using the *** the results suggest that the as-prepared SiQDs can be a potential fluorescent probe for application in antibacterial and analysis.

关键词： silicon quantum dots Antibacterial activity Reactive oxygen species Tetracycline detection

Ultrafast optical spectroscopy of surface-modified silicon quantum dots: unraveling the underlying mechanism of the ultrabright and color-tunable photoluminescence

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Light(Science & Applications) 2015年第1期4卷 524-531页

作者： Lei Wang Qi Li Hai-Yu Wang Jing-Chun Huang Ran Zhang Qi-Dai Chen Huai-Liang Xu Wei Han Zheng-Zhong Shao Hong-Bo Sun State Key Laboratory on Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China College of Physics Jilin UniversityChangchun 130012China State Key Laboratory of Molecular Engineering of Polymers Advanced Material LaboratoryDepartment of Macromolecular ScienceFudan UniversityShanghai 200433China

In this work,the fundamental mechanism of ultrabright fluorescence from surface-modified colloidal silicon quantum dots is investigated in depth using ultrafast *** underlying energy band structure corresponding to such highly efficient direct bandgap-like emissions in our surface-modified silicon quantum dots is unraveled by analyzing the transient optical spectrum,which demonstrates the significant effect of surface molecular *** is observed that special surface modification,which creates novel surface states,is responsible for the different emission wavelengths and the significant improvement in the photoluminescence quantum *** this essential understanding,surface-modified silicon quantum dots with deep blue to orange emission are successfully prepared without changing their sizes.

关键词： quantum confinement silicon quantum dots surface molecular engineering ultrafast spectroscopy wave function modification

Bifunctional silicon quantum dots sensing platform for selective andsensitive detection of p-dihydroxybenzene with double signals

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Bifunctional silicon quantum dots sensing platform for selec...

Research of synthesis and neural network training on double quantum dot colorimetric fluorescent probe for freshness detection

第十一届全国化学生物学学术会议

作者： Yinhui Yi School of the Environment and Safety Engineering Jiangsu University

The similar structures and properties of pdihydroxybenzene（p-DHB） with catechol（CC） make the selective and reliable determination of p-DHB from CCs being still a formidable challenge[1]. In this work, by preparing CC stabilized silicon quantum dots（C-SiQDs） simultaneously as a catalyst and fluorescence indicator, a novel nanosensing platform was successfully developed to selectively and sensitively detect p-DHB with double signals: fluorescence and colorimetric. For detecting p-DHB, C-SiQDs could catalyze the oxidation of p-DHB to form benzoquinone（BQ）, an intermediate, which lead to the color change from pale yellow to dark brown and the efficient quenching the fluorescence of C-SiQDs. While for CC in samples, it could not contact C-SiQDs surface due to the great steric hindrance effect from CC on quantum dots surface, thus restricting the oxidation of CC and production of BQ, and leading that the obtained C-SiQDs have no response towards CC.

关键词： p-Dihydroxybenzene Catechol silicon quantum dots Fluorescence Colorimetric

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Frontiers of Chemical Science and Engineering 2024年第10期18卷 145-157页

作者： Caihong Lv Yuewei Zheng Zhihao Guan Jun Qian Houbin Li Xinghai Liu Hubei Engineering Technology Research Center of Spectrum and Imaging Instrument Electronic Information SchoolWuhan UniversityWuhan 430072China School of Nursing Wuhan UniversityWuhan 430072China

There are many disadvantages such as small detection range and environmental restrictions on application conditions,when the single quantum dot powder or solution is used for fluorescent probe *** this paper,the blue fluorescent silicon quantum dots and green fluorescent carbon quantum dots were prepared,and their fluorescence color changes after mixing in different proportions were investigated under different pH *** the two quantum dots were mixed with a concentration of 0.1 mg·mL^(-1) and a mass ratio of 1:1,the fluorescence color change could be better displayed at a pH from 1 to ***,the double quantum dots were prepared into two forms(ink and film),successfully realizing the device application of the fluorescent *** films and inkjet-printed labels were used to test the spoilage of food(pork,milk,etc.),and the color change data of the labels were collected during the spoilage *** data were used for neural network training to predict the spoilage changes of foods.

关键词： silicon quantum dots carbon quantum dots fluorescent probe pH freshness

Synthesis of temperature and salt resistance silicon dots for effective enhanced oil recovery in tight reservoir

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Petroleum Science 2024年第5期21卷 3390-3400页

作者： Cheng Liu Biao Zhou Bing-Shan Wang Huan Wang Qing You Guang Zhao Cai-Li Dai Beijing Key Laboratory of Unconventional Natural Gas Geological Evaluation and Development Engineering China University of GeosciencesBeijing100083China School of Energy Resources China University of GeosciencesBeijing100083China Chengdu Huayang Town Chengdu Natural Gas Chemical General Factory Chengdu610213SichuanChina School of Petroleum Engineering China University of PetroleumQingdao266580ShandongChina

The intensive development of tight reservoirs has positioned them as a strategic alternative to conventional oil and gas resources. Existing enhanced oil recovery(EOR) methods struggle to effectively exploring reservoir oil, resulting in low recovery rates. Novel and effective means of developing tight reservoirs are urgently needed. Nanomaterials have shown promising applications in improving water flooding efficiency, with in-depth research into mechanisms that lower injection pressure and increase water injection volumes. However, the extent of improvement remains limited. In this study, a silicon quantum dots(Si-QDs) material was synthesized via a hydrothermal synthesis method and used to prepare a nanofluid for the efficient recovery of tight reservoir. The Si-QDs, with an approximate diameter of 3 nm and a spherical structure, were surface functionalized with benzenesulfonic acid groups to enhance the performance. The developed nanofluid demonstrated stability without aggregation at 120℃ and a salinity of 60000 mg/L. Core flooding experiments have demonstrated the attractive EOR capabilities of Si-QDs, shedding light of the EOR mechanisms. Si-QDs effectively improve the wettability of rocks, enhancing the sweeping coefficient of injected fluids and expanding sweeping *** this sweeping region, Si-QDs efficiently stripping adsorbed oil from the matrix, thus increasing sweeping efficiency. Furthermore, Si-QDs could modify the state of pore-confined crude oil, breaking it down into smaller particles that are easier to displacement in subsequent stages. Si-QDs exhibit compelling EOR potential, positioning them as a promising approach for effectively developing tight oil reservoirs.

关键词： silicon quantum dots Tight reservoir Microfluidic Micro-CT Enhanced oil recovery Temperature and salt resistance

Surface brightens up Si quantum dots: direct bandgap-like size-tunable emission

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Light(Science & Applications) 2013年第1期2卷 242-247页

作者： Katerina Dohnalova Alexander N Poddubny Alexei A Prokofiev Wieteke DAM de Boer Chinnaswamy P Umesh Jos MJ Paulusse Han Zuilhof Tom Gregorkiewicz Van der Waals-Zeeman Institute University of AmsterdamNL-1098 XH AmsterdamThe Netherlands Laboratory of Organic Chemistry Wageningen University6703 HB WageningenThe Netherlands Department of Chemical and Materials Engineering King Abdulaziz UniversityJeddahSaudi Arabia Ioffe Physical-Technical Institute RAS 26 Polytechnicheskaya194021 Saint-PetersburgRussia Current address:MIRA Institute Department of Biomedical ChemistryUniversity of TwenteBuilding Zuidhorst EnschedeThe Netherlands

Colloidal semiconductor quantum dots(QDs)constitute a perfect material for ink-jet printable large area displays,photovoltaics,light-emitting diode,bio-imaging luminescent markers and many other *** this purpose,efficient light emission/absorption and spectral tunability are necessary *** are currently fulfilled by the direct bandgap ***-QDs could offer the solution to major hurdles posed by these materials,namely,toxicity(e.g.,Cd-,Pb-or As-based QDs),scarcity(e.g.,QD with In,Se,Te)and/or *** we show that by combining quantum confinement with dedicated surface engineering,the biggest drawback of Si—the indirect bandgap nature—can be overcome,and a‘direct bandgap’variety of Si-QDs is *** demonstrate this transformation on chemically synthesized Si-QDs using state-of-the-art optical spectroscopy and theoretical *** carbon surface termination gives rise to drastic modification in electron and hole wavefunctions and radiative transitions between the lowest excited states of electron and hole attain‘direct bandgap-like’(phonon-less)*** results in efficient fast emission,tunable within the visible spectral range by QD *** findings are fully justified within a tight-binding theoretical *** the C surface termination is replaced by oxygen,the emission is converted into the well-known red luminescence,with microsecond decay and limited spectral *** that way,the‘direct bandgap’Si-QDs convert into the‘traditional’indirect bandgap form,thoroughly investigated in the past.

关键词： direct bandgap optical spectroscopy optoelectronics organic capping silicon quantum dots tight binding model