APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Jishu Han,Ying Liu,Fangxu Dai,Ruiyang Zhao,Lei Wang
Novel CdSe/CaTiO 3 nanocomposites are prepared in aqueous phase and used for photocatalytic hydrogen production. The modification of CdSe QDs on the surface of CaTiO 3 sheet-like structure effectively increases visible light absorption of nanocomposites, improves the separation and transfer of photoinduced electrons and prevents the recombination of electron-hole pairs. Experimental results show that obtained CdSe/CaTiO 3 nanocomposites possess significantly enhanced photocatalytic hydrogen production performance. The photocatalytic hydrogen production amount of CdSe/CaTiO 3 is 48 times higher than that of pure CaTiO 3 and 4.14 times higher than that of CdSe QDs. Meanwhile, CdSe/CaTiO 3 nanocomposites display high stability and recyclability, which is beneficial for photocatalytic hydrogen production application.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Peng Wang,Xiao Li,Jialin Fang,Danzhen Li,Jing Chen,Xiaoyun Zhang,Yu Shao,Yunhui He
Anatase TiO 2 with exposed {0 0 1} facets (denoted as T001) is becoming one of the hotspots in photocatalytic field due to the highly reactive {0 0 1} facets. Nowadays, to further extend the applications of T001 in visible region, researchers are struggling to develop T001-based visible-light-responsive photocatalysts. In this paper, for the first time, CdSe quantum dots (QDs)-decorated T001 (denoted as CS-T001) was synthesized successfully via a facile method and demonstrated as a highly efficient and stable photocatalyst for reduction of nitro aromatics under visible light irradiation. Besides the obviously extended light absorption in visible region, the decoration of CdSe QDs onto T001 would remarkably improve the transfer and separation efficiency of photogenerated charge carriers, resulting in the much higher activity of CS-T001 as compared with pure T001 and CdSe QDs. Serving as the accepted sites for photoelectrons generated from CdSe QDs, the substrate T001 also plays a vital role. First, T001 offers highly active reaction sites due to the much higher surface energy of {0 0 1} facet than that of {1 0 1} facet. Second, compared with CdSe QDs-decorated anatase TiO 2 with exposed {1 0 1} facets (denoted as CS-T101), CS-T001 can generate electrons with stronger reducibility to participate in the photocatalytic reduction process. Third, the aggregation of T001 nanosheets gives rise to the porous structures with slit-like pores, providing efficient transport pathways to reactant and product molecules. Fourth, CS-T001 possesses much higher separation efficiency of photogenerated charge carriers as compared to CS-T101. We believe that our work could not only provide a facile method for fabricating novel QDs-decorated T001 photocatalysts but also help us to realize the synergy between decoration of QDs and exposure of TiO 2 {0 0 1} facets during the photocatalytic reaction process.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ChemPlusChem
·
2018
·Vol. 83
·期 12
·1088-1096
·
IF 3.205
Ping Wang,Chuanping Li,Minmin Wang,Yongdong Jin
Graphical Divalent nickel can be decorated onto CdS/CdSe core/shell quantum dots (QDs) in a controlled fashion. Under optimized conditions these QDs catalyze light-induced H 2 evolution from water with a turnover frequency of 322 h −1 with respect to Ni and a quantum yield of 12.3 % at 520 nm. The search for a low-cost, noble-metal-free cocatalyst to replace expensive Pt for hydrogen (H 2 ) photogeneration in water has become a hot research topic, and among these, Ni-based cocatalysts are promising and highly desired. Developing new strategies and protocols to obtain Ni-based cocatalysts with high activity is therefore vitally important. Herein, we develop a new method to efficiently decorate divalent Ni onto pre-synthesized CdS/CdSe core/shell quantum dots (QDs). The concentration of Ni on the QDs can be easily tuned by varying the amount of the Ni precursor introduced during the synthesis. Further analyses reveal that Ni 2+ can be strongly decorated onto QDs. Impressively, the Ni-decorated QDs displayed a significantly enhanced H 2 photogeneration performance as compared to the two components prepared separately. Through the optimization of the Ni concentration on the QDs, the turnover frequency (TOF) with respect to Ni and quantum yield ( ) at 520 nm for H 2 evolution from water could reach 322 h −1 and 12.3 %, respectively. A possible mechanism has also been proposed and discussed in detail.
研究领域:
材料科学
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能源化学
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
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2012
·
IF 3.832
Xingtian Yin,Wenxiu Que,Duan Fei,Haixia Xie,Zuoli He,Gangfeng Wang
Strategies employed to fabricate an efficient photoanode with ZnO nanowires (NWs) arrays and CdS–CdSe co-sensitizers were investigated. A detailed procedure for growing long ZnO NWs which are suitable for the application in quantum dot sensitized solar cells was discussed, and several optimized parameters were obtained for fabrication of the ZnO NWs with large aspect ratio. CdS and CdSe layers were deposited on the surface of the ZnO NWs by a successive ionic-layer adsorption and reaction method and the deposition process was optimized according to the performance of the solar cells fabricated with the ZnO/CdS NWs and the ZnO/CdS/CdSe NWs arrays, respectively. The relationship between the thickness of the sensitizer layer and the performance of the devices was also discussed in detail. Transmission electron microscopy observation shows that ∼7 nm thick CdS layer and ∼5 nm thick CdSe layer can be easily achieved on the ZnO NWs at an optimal deposition condition. UV–vis absorption spectra demonstrate that the light absorption range of the ZnO/CdS/CdSe NWs can be almost extended to the whole visible range. Through an optimization of the photoanode fabrication, which mainly includes the synthesis of the ZnO NWs arrays and the deposition of the CdS and CdSe layers, a short circuit current density as high as 18.63 mA/cm 2 with an overall efficiency of 3.06% can be obtained for the resulting device.
研究领域:
材料科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2015
·
IF 4.772
Yunfang Ji,Wei Guo,Huihui Chen,Longshuai Zhang,Song Chen,Mutian Hua,Yuhan Long,Zhuo Chen
Constructing unique nanocomposites to facilitate charge transfer and promote catalytic activity provides a promising approach for enhancing solar-to-hydrogen efficiency. However, revealing the catalytic surface state and understanding their roles in the photocatalytic process remain elusive. Here, we develop a facile and mild solution method for ultrathin TiO2 nanosheets with a large specific surface area and enhanced surface Ti3+ accumulation. Moreover, we demonstrate a hybrid nanosystem composed of ultrathin 2D TiO2 nanosheets directly coupled with 0D CdSe QDs for hydrogen generation. The 0D CdSe QDs increase visible light absorption ability after being coupled with the TiO2 nanosheets. Owing to the synergistic effect between the quantum dots and nanosheets, the apparent quantum efficiency increases to 45% at 380 and 450 nm, and the H2 evolution exhibits a 10-fold enhancement. EPR results indicate that the surface Ti3+ greatly promotes H free radical production due to the redox couple Ti3+/Ti4+ providing an efficient route for the photoexcited electron–hole separation. Our findings provide new insights toward understanding and exploiting highly efficient photocatalyst.
研究领域:
材料科学
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能源化学
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光催化
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
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2013
·
IF 5.437
Kai Yan,Rui Wang,Jingdong Zhang
A novel photoelectrochemical (PEC) biosensing platform was constructed by assembling CdSe quantum dots (QDs) and DNA on liquid phase deposited TiO 2 (DNA–CdSe/TiO 2 ) film electrode. The transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis indicated that CdSe QDs were homogeneously assembled on TiO 2 film. The UV–visible diffuse reflectance spectra (DRS) showed that CdSe and DNA could effectively enhance the absorption of TiO 2 film to visible light. The obtained electrode showed a sensitive PEC response to o -aminophenol (OAP) under visible light irradiation . Due to the interaction between DNA and OAP, the response of OAP was improved by DNA immobilized on the sensing film. Under optimized conditions, the photocurrent was linearly proportional to OAP in the concentration range from 4.0×10 −7 to 2.7×10 −5 mol L −1 , with a detection limit (3 S/N) of 8.0×10 −8 mol L −1 . The novel strategy could provide a fast and sensitive method for OAP determination.
研究领域:
生物传感技术
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材料科学
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分析化学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Yi Peng,Ying Yan,Jing Wang,Ziyang Xiang,Yanmei Li,Junhui Yang,Jinglin Yin,Wenlei Wang,Hongbo Xiao
In this study, CdSe cluster-modified biogenic α − FeOOH based on macroporous biochar was constructed from rhizosphere iron plaque via pyrolysis. An ultrahigh H 2 O 2 production rate of 655.75 μmol/L was achieved by the photocatalysis-self-Fenton system within 30 min under visible light irradiation. α-FeOOH, with abundant iron ions, can directly activate H 2 O 2 to produce abundant ⋅OH radicals. It was found that As(III) (10 mg/L) could be completely degraded within 20 min. Electron spin resonance spectroscopy (ESR) and density functional theory (DFT) revealed that a suitable energy band structure was achieved by the introduction of CdSe clusters; thus, O 2 was mainly reduced to H 2 O 2 through a two-electron reduction route in the reaction system. The photogenerated electrons promoted the conversion of Fe(III)/Fe(II) by reacting with Fe(III) in α-FeOOH. The presence of H 2 O 2 and Fe 2+ in this system accelerates the oxidation of As(III) by a Fenton-like reaction.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
TOPICS IN CATALYSIS
·
2021
·Vol. 64
·期 7
·567-575
·
IF 2.91
Wu Fan,Yu Shan,Zhong Yunqian,Chen Weiwei,Dan Meng,Zou Yanzhao,Yuan Chengdong,Zhou Ying
Hydrogen is a promising energy carrier to replace traditional fossil fuel and could be obtained by the artificial photosynthesis. Herein, a homogenous system combined CdSe quantum dots (QDs) and graphene oxide (GO) (GO/CdSe QDs) were prepared by simple ultrasonication and stirring method for highly efficient photocatalytic hydrogen evolution. Notably, the optimized photocatalytic H 2 evolution rate reached as high as 33.88 mmol g −1 h −1 for GO/CdSe QDs, which is about 7.9 times than that of pure CdSe QDs. The X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM) confirmed that the GO has been successfully coupled with CdSe QDs and has ignorable influence on the original crystal structure and morphology of CdSe QDs. Importantly, we found that the hydrophilicity of GO is necessary to ensure its intact interaction with CdSe QDs for the continuous H 2 production. The significant activity enhancement mainly attributed to the acceleration of charge migration and dynamics of proton reduction after introducing GO, which has been proved by electrochemical measurements, photoluminescence spectroscopy (PL) and dynamic decay of samples.
研究领域:
材料科学
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能源化学
·
纳米技术
✓ 已验证
DOI
高影响因子
ACS Nano
·
2020
·
IF 14.588
Junjie Hao,Yiwen Li,Jun Miao,Rulin Liu,Jiagen Li,Haochen Liu,Qiushi Wang,Huan Liu,Marie-Hélène Delville,Tingchao He,Kai Wang,Xi Zhu,Jiaji Cheng
Ligand-induced chirality in asymmetric CdSe/CdS core–shell nanocrystals (NCs) has been extensively applied in chiral biosensors, regioselective syntheses and assemblies, circularly polarized luminescence (CPL), and chiroptic-based devices due to their excellent physiochemical properties, such as the tunable quantum confinement effects, surface functionality, and chemical stability. Herein, we present CdSe/CdS NCs with various morphologies such as nanoflowers, tadpoles, and dot/rods (DRs) with chirality induced by surface chiral ligands. The observed circular dichroism (CD) and CPL activities are closely associated with the geometrical characteristics of the nanostructures, such as the shell thickness and the aspect ratio of the CdSe/CdS NCs. Furthermore, in situ observations of the growth of tadpoles with a single tail indicate that the CD response is mainly attributed to the CdS shell, which has a maximum tail length of ∼45 nm (approximately λ/10 of the incident light wavelength). On the other hand, the CPL activity is only related to the CdSe core, and the activity benefits from a thin CdS shell with a relatively high photoluminescence quantum yield (QY). Further theoretical models demonstrated the aspect-ratio-dependent g-factor and QY variations in these asymmetric nanostructures. These findings provide insights into not only the asymmetric synthesis of CdSe/CdS NCs, but also the rational design of CdSe/CdS nanostructures with tunable CD and CPL activities.
研究领域:
材料科学
·
光学
·
纳米技术
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Shunyong Wei,Ming Yang,Hui Sun,Faming Li,Fei Xiao,Jihua Zou,Aobo Ren,Yixuan Huang,Zhihui Xiong,Liming Yuan,Hao Xu,Tixian Zeng,Jiang Wu,Zhiming M. Wang
CdSe single crystals (SCs), with a relatively high atomic number, large X-ray absorption coefficients, and high carrier mobility, are expected to provide high-performance detection for X-ray. However, the difficulty of growing high-quality CdSe SC has severely limited its application in X-ray detection. In this work, we develop an unconstrained physical gas phase method and in situ annealing process to grow high-quality CdSe SCs under unconstrained conditions. Using this method, CdSe SCs exhibit natural exposure planes, ultrahigh resistivity of 5.43 × 1012 to 1.29 × 1013 Ω cm and high μτ product of 1.3 × 10–2 to 1.5 × 10–2 cm2 V–1. It is also observed that CdSe SC X-ray detectors exhibit a record sensitivity of 2.08 × 105 μC Gyair–1 cm–2 and a low detection limit of 85 nGyair s–1, which are both desired in medical diagnostics. Moreover, those devices with different crystal directions provide anisotropic X-ray detection performance. Our findings pave a new avenue to exploit high-performance CdSe SC X-ray detectors.
研究领域:
材料科学
·
医学影像
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Applied Materials Today
·
2018
·
IF 0
Bowen Zhao,Zhongquan Wan,Junsheng Luo,Chunyang Jia,Xingzhao Liu,Ruilin Wang
Sb 2 Se 3 with its excellent optical, electrical properties emerging as a promising next-generation light harvesting material has gained immense research interest. However, in the Sb 2 Se 3 photovoltaic devices , the impediment of charge transport within the layered structure dragged down the device performance. Here, for the first time, we reported the air-stabled Sb 2 Se 3 sensitized solar cells (SSCs) modified with CdSe interlayer at the TiO 2 /Sb 2 Se 3 heterojunction through successive ionic layer adsorption and reaction (SILAR) process. CdSe modification provided the reduced TiO 2 work function, enhanced optical absorption and suppressed charge recombination. The short-circuit current density, fill factor and open-circuit voltage of the Sb 2 Se 3 SSCs were all remarkably improved. When CdSe layer with five SILAR cycles was applied, the device power conversion efficiency (PCE) was as high as 1.96%, which was the highest recorded PCE of Sb 2 Se 3 nanoparticle based solar cells. Our work illustrates that interfacial engineering provided a useful route to adjust the interface configuration in Sb 2 Se 3 based solar cell and optoelectronic applications .
研究领域:
材料科学
·
光伏技术
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纳米技术
✓ 已验证
产品关联
DOI
Nanoscale
·
2021
·Vol. 13
·期 46
·19474-19483
·
IF 7.79
Weishuo Xing,Shuang Zhang,Ruoting An,Wengang Bi,Chong Geng,Shu Xu
Tetrapod CdSe/CdS quantum dots (QDs) have attracted extensive research interest in light-emitting applications due to their anisotropic optical properties and large absorption cross-section. Traditional synthesis methods for tetrapod CdSe/CdS QDs usually employ fatty phosphonic acid ligands to induce the growth of wurtzite CdS arms on cubic CdSe QDs at high temperatures (350–380 °C). Here, a low temperature (120 °C) route was developed for the synthesis of tetrapod CdSe/CdS QDs using mixed amine ligands instead of phosphonic acid ligands. A study of the growth mechanism reveals that the amine ligands induce the orientation growth of cubic CdS arms on wurtzite CdSe QDs through a pyramid-shaped intermediate structure. The low reaction temperature facilitates the growth control of the tetrapod CdSe/CdS QDs through a microfluidic reactor. This study substantially simplifies the synthetic chemistry for the anisotropic growth of CdS on CdSe QDs, paving the way for green and economic production of tetrapod CdSe/CdS QDs towards efficient light-emitting applications.
研究领域:
材料科学
·
纳米技术
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
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