Nanomaterials
·
2022
·Vol. 12
·期 11
·1898
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IF 5.719
Xuan Chen,Jin Li
With the increasing water pollution, traditional treatments cannot sufficiently remove pollutants, thereby prompting the development of photocatalysts. In this study, ZnO–carbon cloth (CC) and spherical ZnO/CdSe–CC heterostructures with different CdSe loadings were synthesized using an ultrasonic-hydrothermal method on flexible CC. Z20CdSe–CC (ZnO with 20 mg CdSe loaded on CC) exhibited the best visible-light-responsive photocatalytic performance, with approximately 83.5% methylene blue reduced in 180 min. In addition, the degradation efficiency of Z20CdSe–CC was maintained at 70.9% after three cycles in relation to that of the ZnO powder. The synergistic effect of CdSe and CC not only effectively widened the light absorption range of ZnO/CdSe–CC but also further promoted the effective transfer of carriers and realized an efficient photocatalytic degradation process. Therefore, the ZnO/CdSe–CC photocatalytic material with CC as the flexible substrate exhibited high photocatalytic activity and stability in environmental remediation. This provides a design idea for the development of an efficient and flexible photocatalytic material in line with the concept of green chemistry.Keywords:ZnO/CdSe–CC;heterostructure;photocatalysis
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
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2012
·
IF 2.234
Hucheng Zhang,Dong Xu,Jianji Wang
High fluorescence efficiency is desired for the practical applications of semiconductor nanocrystals (NCs) in many fields. However, reducing photoluminescence (PL) efficiency is usually observed after ligand exchanges on nanocrystal surfaces due to the generation of surface defects. Here, we report the preparation of polyvinylpyrrolidone-capped CdSe NCs (CdSe/PVP), and show the PL enhancement of CdSe/PVP NCs under UV radiation in the air. The experimental results indicate that the PL-enhanced mechanism of the NCs in methanol results from passivation of the lyates in that they act as the hole-acceptors. By screening of hole scavenger, furthermore, it is found that ditertbutyl peroxide is a better passivators of surface defects, and promotes the PL efficiency of CdSe/PVP NCs to achieve a value 110 times higher than that of as-prepared CdSe/PVP NCs. The photopassivation in the presence of organic molecules provides a prefertial, inexpensive path to harvest NCs with high PL efficiency.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2011
·
IF 3.463
Zhenhua Yang,Shiyan Chen,Weili Hu,Na Yin,Wen Zhang,Cao Xiang,Huaping Wang
Flexible luminescent membranes based on bacterial cellulose (BC) were successfully fabricated by the in situ synthesis of the CdSe nanoparticles on the BC nanofibers. X-ray diffraction (XRD) patterns and field emission scanning electron microscopy (FE-SEM) revealed that CdSe nanoparticles were homogeneously dispersed on the BC nanofibers. The thermal stability of BC was greatly increased with the inclusion of CdSe nanoparticles. The CdSe/BC nanocomposite exhibited good photoluminescence properties and excellent mechanical properties. This work provides an effective method for the construction of flexible BC membranes with photoluminescence properties, which are promising for applications in the fields of security papers, sensors and flexible luminescent membranes.
研究领域:
材料科学
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纳米技术
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光电技术
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产品关联
DOI
高影响因子
JOURNAL OF POLYMER ENGINEERING
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2022
·Vol. 42
·期 8
·787-793
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IF 1.624
Zhiyi Zhang,Zhichun Li,Fengbo Zhu,Lan Jia,Yudong Wang,Jingxin Zhu,Yanlong Ma,Hongwei He,Yuyuan Fan,Ying Zhang,Pengfei Fei,Yu Feng
Polyacrylonitrile (PAN) was often used as a composite fiber matrix due to its good spinning characteristics. Herein, photoluminescent quantum dot-doped nanofibers with tunable diameters were successfully prepared using electrospinning by adding CdSe/CdS quantum dots (QDs) in PAN spinning solution. The morphology and structure of CdSe/CdS-PAN nanofibers were characterized by scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR), and the mechanical and photoluminescent properties of CdSe/CdS-PAN nanofibers were investigated. Stable photoluminescent nanofibers were obtained owning to the improved stability of photoluminescent property of CdSe/CdS QDs in the PAN nanofiber. The stable photoluminescent CdSe/CdS-PAN nanofibers might be used for anti-fake labels, ultraviolet sensors, smart textiles and optoelectronic devices.
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
OPTICAL MATERIALS
·
2023
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IF 3.9
Ziheng Wang,Xueying Chu,Jinhua Li,Zhankun Weng,Mingze Xu,Yingjiao Zhai,Li Ma,Xiaojun Wang
The polarization-sensitive optical properties of semiconductor nanorods (NRs) are attractive characteristics for optical devices . Although oriented NR films can provide convenient integration and new application opportunities, the realization of large-area NR films with polarized photoluminescence (PL) remains a challenge. Herein, we fabricated ordered CdSe/CdS NR films on an arbitrary substrate using the Langmuir-Blodgett technology. Polarization-sensitive PL was observed for the NR films. The band-edge exciton fine structure owing to the rod-like morphology and the dielectric effect of the orderly arranged NRs were discussed with a focus on the contribution to polarized photons. The degree of linear polarization of the CdSe/CdS NR films excited a circularly polarized light was approximately 0.30. When linearly polarized ultraviolet (UV) light was used as the excitation source, the PL intensity of the NR films periodically varied with the polarization direction of the UV light. The corresponding PL polarization (i.e., “excitation polarization”) was approximately 0.28. The polarization-sensitive fluorescence (approximately 526 nm) excited by the UV-polarized light (325 nm) demonstrates the potential for realizing low-cost polarization-sensitive devices using only a visible light charge-coupled device system.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2024
·Vol. 160
·期 16
·
IF 3.1
Wang Yang,Liang Pan,Men Yumeng,Jiang Meizhen,Cheng Lin,Li Jinlei,Jia Tianqing,Sun Zhenrong,Feng Donghai
Chiral quantum dots (QDs) are promising materials applied in many areas, such as chiral molecular recognition and spin selective filter for charge transport, and can be prepared by facile ligand exchange approaches. However, ligand exchange leads to an increase in surface defects and reduces the efficiencies of radiative recombination and charge transport, which restricts further applications. Here, we investigate the light-induced photoluminescence (PL) enhancement in chiral L- and D-cysteine CdSe QD thin films, providing a strategy to increase the PL. The PL intensity of chiral CdSe QD films can be significantly enhanced over 100 times by continuous UV laser irradiation, indicating a strong passivation of surface defects upon laser irradiation. From the comparative measurements of the PL intensity evolutions in vacuum, dry oxygen, air, and humid nitrogen atmospheres, we conclude that the mechanism of PL enhancement is photo-induced surface passivation with the assistance of water molecules.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Jiayou Xue,Xuke Yang,Xiaoqing Bao,Liuchong Fu,Sen Li,Menglin Huang,Jun Wang,Haisheng Song,Shiyou Chen,Chao Chen,Kanghua Li,Jiang Tang
Cadmium selenide (CdSe) solar cells have proven to be a remarkable potential top cell for a silicon-based tandem application. However, the defects and short carrier lifetimes of CdSe thin films greatly limit the solar cell performance. In this work, a Te-doped strategy is proposed to passivate the Se vacancy defects and increase the carrier lifetime of the CdSe thin film. The theoretical calculation helps to reveal the mechanism of nonradiative recombination of the CdSe thin film in depth. After Te-doping, the calculated capture coefficient of CdSe can be reduced from 4.61 × 10–8 cm3 s–1 to 2.32 × 10–9 cm3 s–1. Meanwhile, the carrier lifetime of CdSe thin film is increased nearly 3-fold from 0.53 to 1.43 ns. Finally, the efficiency of the Cd(Se,Te) solar cell is improved to 4.11%, about a relative 36.5% improvement compared to the pure CdSe solar cell. Both theoretical calculations and experiments prove that Te can effectively passivate bulk defects and improve the carrier lifetime of CdSe thin films, deserving further exploration to improve solar cell performance.
研究领域:
材料科学
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光伏技术
✓ 已验证
DOI
PubMed
高影响因子
Integrative Biology
·
2012
·Vol. 4
·期 3
·301-309
·
IF 4.509
Ni Xiaoling
People exposed to engineered nanomaterials have potential health risks associated. Human α-amylase is one of the key enzymes in the digestive system. There are few reports about the influence of quantum dots (QDs) on the digestive enzymes and their inhibition system. This work focused on the toxic effect of CdTe/CdSe QDs on the interactions between α-amylase and its natural inhibitors. Thirty-six dietary polyphenols, natural α-amylase inhibitors from food, were studied for their affinities for α-amylase in the absence and presence of CdTe/CdSe QDs by a fluorescence quenching method. The magnitudes of apparent binding constants of polyphenols for α-amylase were almost in the range of 105–107 L mol−1 in the presence of CdTe/CdSe QDs, which were higher than the magnitudes of apparent binding constants in the absence of CdTe/CdSe QDs (104–106 L mol−1). CdTe/CdSe QDs obviously improved the affinities of dietary polyphenols for α-amylase up to 389.04 times. It is possible that the binding interaction between polyphenols and α-amylase in the presence of CdTe/CdSe QDs was mainly caused by electrostatic interactions. QDs significantly influence the digestive enzymes and their inhibition system.
研究领域:
生物化学
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毒理学
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食品科学
✓ 已验证
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2018
·
IF 0
Changchang Ma,Xin Yao,Lu Wang,Zihao Cai,Hai Huang,Xin Gao,Rongru Chen,Yang Liu,Pengwei Huo,Yongsheng Yan
A novel plasmonic photocatalysts of Ag@CdSe/Al 2 TiO 5 was successfully prepared via a simple and mild wet-chemical process. The physical and photophysical properties of the as-prepared Ag@CdSe/Al 2 TiO 5 samples were characterized by scanning electron microscopy (SEM), transmission electron microscope (TEM), Ultraviolet–visible diffuse reflection spectroscopy (DRS), photoluminescence emission spectra (PL) and electrochemical impedance spectroscopy (EIS). The interaction between Ag@CdSe and Al 2 TiO 5 has been characterized by X-ray photoelectron spectroscopy (XPS) analysis, and which is facile to the electron transfer between Ag@CdSe and Al 2 TiO 5 and enhancing photocatalytic performance of Ag@CdSe/Al 2 TiO 5 composite photocatalyst. The photocatalytic experiments demonstrat that the Ag@CdSe species can efficiently improve the separation efficiency of photoinducing electrons and holes and consequently improve the methylene blue (MB) photodegradation activity. The 20 wt% Ag@CdSe/Al 2 TiO 5 sample exhibit the most superior photocatalytic activity. A possible photocatalytic mechanism of MB over Ag@CdSe/Al 2 TiO 5 is proposed, which can be attributed the success to the surface plasmon resonance (SPR) effect from Ag/AgCl species.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
产品关联
DOI
Materials
·
2023
·Vol. 16
·期 21
·7007
·
IF 3.4
Yuzhe Wang,Yueqi Zhong,Jiangzhi Zi,Zichao Lian
Conventional single-component quantum dots (QDs) suffer from low recombination rates of photogenerated electrons and holes, which hinders their ability to meet the requirements for LED and laser applications. Therefore, it is urgent to design multicomponent heterojunction nanocrystals with these properties. Herein, we used CdSe quantum dot nanocrystals as a typical model, which were synthesized by means of a colloidal chemistry method at high temperatures. Then, CdS with a wide band gap was used to encapsulate the CdSe QDs, forming a CdSe@CdS core@shell heterojunction. Finally, the CdSe@CdS core@shell was modified through the growth of the ZnS shell to obtain CdSe@CdS@ZnS heterojunction nanocrystal hybrids. The morphologies, phases, structures and performance characteristics of CdSe@CdS@ZnS were evaluated using various analytical techniques, including transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy, fluorescence spectroscopy and time-resolved transient photoluminescence spectroscopy. The results show that the energy band structure is transformed from type II to type I after the ZnS growth. The photoluminescence lifetime increases from 41.4 ns to 88.8 ns and the photoluminescence quantum efficiency reaches 17.05% compared with that of pristine CdSe QDs. This paper provides a fundamental study and a new route for studying light-emitting devices and biological imaging based on multicomponent QDs.
研究领域:
材料科学
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光学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2018
·
IF 4.7
Jing Li,Xiufang Hao,Jinhui Wang,Xiaoyan Cui,Xinxin Li,Shuo Wei,Jun Lu
CdSe nanocrystals, including quantum dots and quantum rods, are a research hotspot in nanomaterials. Recently, it has been found that two-dimensional CdSe semiconductor nanobelts show a unique quantum confinement effect owing to their homogeneous nanoscale thickness. In this study, a series of (CdSe)n·monoamine (n = 1, 2, and 4, monoamine = butylamine, hexylamine, and octylamine) layered inorganic/organic hybrid nanobelts was synthesized by the solvothermal method. These hybrids have a lamellar structure with a few inorganic [CdSe] layers and monoamine layers alternatively stacked along the c axis of their crystallites, which exhibit the typical preferred orientation for layered crystallites and isomorphous [CdSe] layers according to their X-ray diffraction patterns. The [CdSe] layer is a contracted (110) superlattice cell of wurtzite (WZ)-type CdSe with unit cell parameter relations of a ≈ √3aWZ and b ≈ cWZ, and a lamellar nanobelt morphology with the [010] growth direction. These ordered hybrids exhibit prominent split exciton absorption peaks and sharp band edge luminescence owing to the homogeneous thickness of the [CdSe] layers within the hybrids, all of which are comparable with reported WZ-type CdSe colloidal nanosheets and exhibit a prominent two-dimensional exciton quantum confinement effect. The solvothermal reaction was systematically investigated. The multiple stage amine de-intercalation topotactic process was revealed for the WZ-type CdSe nanobelts with the (CdSe)n·monoamine (n = 1, 2, and 4) hybrids as the intermediate phases. The solvothermal synthesis method (70–150 °C) is facile and milder than the traditional hot injection method (>200 °C). Therefore, these hybrids can be considered to be intermediate phases or precursors of WZ-type CdSe nanosheets with a topotactic intralayer [CdSe] structure and also a type of multiple quantum well with extremely thin [CdSe] layers orderly stacked among the monoamine insulating blocking layers.
研究领域:
纳米材料
·
材料科学
·
半导体物理
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Nanomaterials
·
2012
·
IF 1.376
Yitan Li,Lin Wei,Ruizi Zhang,Yanxue Chen,Jun Jiao
Large area rutile TiO2 nanorod arrays were grown on F:SnO2 (FTO) conductive glass using a hydrothermal method at low temperature. CdSe quantum dots (QDs) were deposited onto single-crystalline TiO2 nanorod arrays by a chemical bath deposition (CBD) method to make a photoelectrode. The solar cell was assembled using a CdSe-TiO2 nanostructure as the photoanode and polysulfide solution as the electrolyte. The annealing effect on optical and photovoltaic properties of CdSe quantum-dots-sensitized TiO2 nanorod solar cells was studied systematically. A significant change of the morphology and a regular red shift of band gap of CdSe nanoparticles were observed after annealing treatment. At the same time, an improved photovoltaic performance was obtained for quantum-dots-sensitized solar cell using the annealed CdSe-TiO2 nanostructure electrode. The power conversion efficiency improved from 0.59% to 1.45% as a consequence of the annealing effect. This improvement can be explained by considering the changes in the morphology, the crystalline quality, and the optical properties caused by annealing treatment.
研究领域:
材料科学
·
光伏技术
✓ 已验证
DOI
高影响因子
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