查找使用阿拉丁产品的科研文献

CdS quantum dots: Bared for Oxytetracycline sensing and hyaluronic acid-functionalized bioimaging

Zhenzhen Du,Weiting Zhong,Weifang Deng,Lei Sun,Xu Zhang,Yanbao Zhao

In this paper, Ag + doped CdS quantum dots (Ag:CdS QDs) nanoprobes for obtaining near-infrared (NIR) nanoprobes for antibiotic detection and biological imaging were synthesized via an aqueous phase method based on CdS QDs. The emission wavelength of doped QDs was redshifted from visible region to NIR. Ag:CdS QDs nanoprobes have the characteristics of water solubility, uniform particle size, and fluorescence stability. When the nanoprobes are used to detect a certain concentration of Oxytetracycline (OTC), the fluorescence intensity will change accordingly. Ag:CdS QDs nanoprobes enabled rapid and sensitive detection to OTC within the range of 1.25 to 5.00 μM, the linear correlation equations were y = 29.9 x-18.541 (R 2  = 0.992), with a limit of detection (LOD) as low as 0.076 μM. The feasibility of this method was verified in fresh milk. At the same time, hyaluronic acid (HA) was coated on Ag:CdS QDs nanoprobes to improve the biocompatibility and obtained HA/Ag:CdS QDs nanoprobes that still retained good fluorescence properties and stability. Cell proliferation assay, red cell hemolysis assay, bioimaging experiment, and vivo imaging assay demonstrated that HA/Ag:CdS QDs nanoprobes possessed minimal cytotoxicity, excellent biocompatibility, and efficient cellular internalization via endocytosis, clearance capability, facilitating in vivo imaging. Therefore, Ag:CdS QDs nanoprobes can be used for detection OTC and HA/Ag:CdS QDs nanoprobes for bioimaging.

A novel method for fabrication of CdS quantum dot-sensitized solar cells

Zhang Yu,Tian Jianhua,Jiang Kejian,Huang Jinhua,Zhang Lipeng,Wang Huijia,Bao Bin,Song Yanlin

In this report, a novel and facile in situ gas–solid reaction method has been developed for the deposition of CdS quantum-dots (QDs) on a mesoscopic TiO 2 film. In the approach, cadmium nitrate solution was first coated on mesoporous TiO 2 films, and subsequently transformed into CdS QDs (with size about 2–3 nm) by reaction with hydrogen sulfide (H 2 S) gas generated in a closed container at room temperature. Different from the conventional solution techniques, this method offers new opportunities for rapid and facile deposition of CdS QD-coated TiO 2 films without the introduction of the by-products. With the CdS QDs-decorated TiO 2 active electrodes, the liquid and solid solar cells were fabricated with power conversion efficiencies ( PCEs ) of 1.90 and 0.80%, respectively.

CDs/FeCo-ONSs Composite with Peroxidase-like Activity for Ascorbic Acid Detection

Xue Liu,Yuanhang Wei,Wenjing Wang

Nitrogen-doped carbon dots (CDs) were fabricated via a one-pot hydrothermal route using hydroquinone and o-phenylenediamine as dual precursors. The as-prepared CDs were then anchored onto iron-cobalt oxide nanosheets (FeCo-ONSs) to construct a composite nanozyme, denoted as CDs/FeCo-ONSs. Although FeCo-ONSs possess intrinsic peroxidase-like (POD-like) activity, the integration of CDs with FeCo-ONSs resulted in a remarkable enhancement of catalytic performance. Specifically, in the presence of hydrogen peroxide (H2O2), the CDs/FeCo-ONS composite promoted the efficient oxidative transformation of 3,3′,5,5′-tetramethylbenzidine (TMB), leading to the formation of a blue-colored oxidized product. Based upon the enhanced POD-like activity of CDs/FeCo-ONSs, a highly sensitive colorimetric sensor was developed for the detection of ascorbic acid (AA). This method exhibited a wide linear detection range of 0.1 to 50 µM with a low limit of detection (LOD) of 0.018 µM. Furthermore, the developed method was successfully applied to the determination of AA in commercial beverages and fresh fruits, verifying its potential feasibility for practical applications in food quality control.

Rh-modified Cs2AgBiBr6/CdS heterojunction for synergistic photocatalytic ethanol dehydrogenation and acetalization

Yalin Yang,Wei Lu,Xiaolong Yang,Lyuzhou Ye

A ternary CABB/CdS–Rh heterojunction with Type-I band alignment and Rh electron trapping for synergistic charge separation. • DFT-Bader analysis quantifies Rh-induced charge redistribution, with net charge increased from 0.20 to 0.30 |e|. • CABB/CdS-Rh yields 49.15 mmol·g -1 ·h -1 H 2 (STH 0.19%) with tunable selectivity for acetaldehyde/acetal. Photocatalytic direct dehydrogenation of ethanol remains critically constrained by the narrow visible-light response and inefficient charge carrier separation of conventional photocatalysts. Herein, a Rh-modified Cs 2 AgBiBr 6 /CdS heterojunction is fabricated for coupled ethanol dehydrogenation, H 2 production and acetal generation under mild conditions. Density Functional Theory (DFT) calculations validate the tailored charge transfer behavior via Bader charge and differential charge density analyses. Bader charge analysis shows that Rh incorporation increases the interfacial net charge variation from 0.20 |e| to 0.30 |e| and introduces a local variation of 0.42 |e| around Rh sites, thereby suppressing charge recombination and promoting carrier separation. Control experiments confirm that 1D CdS nanorods deliver better charge transport than 2D CdS nanosheets, and surface cocatalyst anchoring is indispensable for efficient hydrogen evolution. Rh outperforms other tested metals (Pd, Pt, Au, Ni), achieving an H 2 evolution rate of 49.15 mmol·g −1 ·h −1 (20.24-fold that of CABB/CdS) and Solar-to-Hydrogen (STH) efficiency of 0.19%. Rh modification tunes liquid-phase product distribution, and the catalyst shows broad alcohol substrate adaptability and robust cycling stability. The synergistic heterojunction engineering and cocatalyst modification strategy presented in this work offers a promising catalyst design paradigm for the valorization of biomass-derived alcohols via photocatalytic conversion. A CABB/CdS-Rh heterojunction photocatalyst is constructed for visible-light-driven ethanol dehydrogenation. The reinforced interfacial charge redistribution, together with the Rh electron-trapping centers, effectively suppresses charge recombination, achieving efficient H 2 production of 49.15 mmol·g −1 ·h −1 with an STH EtOH efficiency of 0.19%. Systematic screening identifies Rh as the optimal cocatalyst, and the catalyst exhibits broad substrate adaptability toward various alcohols, including benzyl alcohol, cyclohexanol, and n-pentanol. This integrated design offers a versatile strategy for the dual valorization of biomass-derived alcohols into H 2 fuel and valuable chemicals. Download: Download high-res image (127KB) Download: Download full-size image

Oxygen Stabilizes Photoluminescence of CdSe/CdS Core/Shell Quantum Dots via Deionization

Zhuang Hu,Shaojie Liu,Haiyan Qin,Jianhai Zhou,Xiaogang Peng

By taking advantage of well-defined spectroscopic signatures of high-quality CdSe/CdS core/shell QDs, the effects of oxygen on photoluminescence (PL) of QDs were studied systematically and quantitatively at both single-dot and ensemble (on substrate and in solution) levels, which reveals a unified yet simple picture. With a sufficient amount of oxygen in the system during photoexcitation, the core/shell QDs in all forms would be deionized timely from the photogenerated and inefficient trion state back to the efficient single-exciton state, with superoxide radicals as the reduction product of oxygen. Under a given excitation power, rates of both spontaneous deionization and photodeionization channels increased by increasing the oxygen pressure, but photoionization of the QDs was barely affected by the oxygen pressure. While stabilizing PL by oxygen was identified for both CdSe plain core and CdSe/CdS core/shell QDs, irreversible photocorrosion was only observed for CdSe plain core QDs, suggesting the importance of high-quality epitaxial shells for QDs in various applications.

Designing Atomic Interface in Sb2S3/CdS Heterojunction for Efficient Solar Water Splitting

Minji Yang,Zeyu Fan,Jinyan Du,Chao Feng,Ronghua Li,Beibei Zhang,Nadiia Pastukhova,Matjaz Valant,Matjaž Finšgar,Andraž Mavrič,Yanbo Li

In the emerging Sb 2 S 3 -based solar energy conversion devices, a CdS buffer layer prepared by chemical bath deposition is commonly used to improve the separation of photogenerated electron-hole pairs. However, the cation diffusion at the Sb 2 S 3 /CdS interface induces detrimental defects but is often overlooked. Designing a stable interface in the Sb 2 S 3 /CdS heterojunction is essential to achieve high solar energy conversion efficiency. As a proof of concept, this study reports that the modification of the Sb 2 S 3 /CdS heterojunction with an ultrathin Al 2 O 3 interlayer effectively suppresses the interfacial defects by preventing the diffusion of Cd 2+ cations into the Sb 2 S 3 layer. As a result, a water-splitting photocathode based on Ag:Sb 2 S 3 /Al 2 O 3 /CdS heterojunction achieves a significantly improved half-cell solar-to-hydrogen efficiency of 2.78% in a neutral electrolyte, as compared to 1.66% for the control Ag:Sb 2 S 3 /CdS device. This work demonstrates the importance of designing atomic interfaces and may provide a guideline for the fabrication of high-performance stibnite-type semiconductor-based solar energy conversion devices.

Synthesis and Characterization of CdS/CISe Quantum Dots with Core–Shell Structure

Qinghua Du,Hui Zhang,Jiapeng Zhang,Xinjian Xie,Guodong Liu,Guifeng Chen

Quantum dots have received great interest due to their excellent optoelectronic properties. However, the surface defects of quantum dots affect the carrier transport and ultimately reduce the photovoltaic efficiency. In this paper, a core–shell quantum dot by hot-injection method is prepared to grow a narrow-band semiconductor layer (CuInSe 2 (CISe) quantumdot) on the surface of a broad-band core material (cadmium sulfide (CdS) nanocrystal). The composition, structure, optical properties, and decay lifetime of CdS/CISe core–shells are investigated in more detail by X-ray diffraction (XRD), transmission electron microscopy (TEM), photoluminescence (PL), UV–vis spectrophotometry, and fluorescence spectroscopy. The CdS/CISe core–shell structure has a broadened absorption range and still shows CISe-related quantum effects. The increased size of the core–shell and the smaller specific surface area of the CISe shell layer lead to a lower carrier complexation chance, which improves the carrier lifetime.

Mn-doped CdS/Cu2O: An S-scheme heterojunction for photocatalytic hydrogen production

Lufang Fan,Jiahui Han,Kai Wei,Changchang Ma,Sheng Feng,Yun Zhou,Xiaojun Dai,Zhiwei Ye,Yang Wang

This study aimed to regulate the band structure and enhance the reduction ability of CdS by substituting it with Mn 2+ . Subsequently, this nano MnCdS solid solution was anchored on the surface of truncated octahedral Cu 2 O through a simple hydrothermal process, forming an S-scheme heterojunction at the interface between MnCdS and Cu 2 O. Equilibrating the Fermi level at the MnCdS/Cu 2 O heterojunction led to spontaneous diffusion of electrons in MnCdS to Cu 2 O, generating an internal electric field that drove the recombination of electrons in the conduction band (CB) of Cu 2 O and holes in the valence band (VB) of MnCdS. Consequently, this process preserved the powerful photogenerated electrons in the CB of MnCdS, facilitating robust photocatalytic hydrogen evolution . The MnCdS/Cu 2 O exhibited a photocatalytic hydrogen evolution rate of 66.3 mmol g −1 h −1 , which was 3.4- and 54.3-times higher than that of MnCdS (19.4 mmol g −1 h −1 ) and Cu 2 O (1.2 mmol g −1 h −1 ), respectively. This study elucidates advanced S-scheme heterojunction catalyst architectures for photocatalytic hydrogen production.

Photo-Tuned Cu/Cu2O/CdS/PPy Heterojunctions for Hg2+ Sensing in Seawater

Minggang Zhao,Zhensen Liang,Ming Li,Hongzhi Cui,Ye Ma

A Highly Efficient Composite Catalyst (Au/Ta3N5)/CdS for Photocatalytic Hydrogen Production

Jinfeng Tian,Xing Wen,Wenfeng Hu,Li Luo,Wei Wang,Keying Lin,Haijuan Zhan,Baojun Ma

As non-noble metal co-catalysts, Nitrides have received extensive attention for their high efficiency and low cost in photocatalytic hydrogen production. In this study, we develop a novel composite co-catalyst of Au/Ta3N5that significantly enhanced the photocatalytic hydrogen production activity of CdS. The activity of photocatalyst (Au/Ta3N5)/CdS is 7.3 times of bare CdS and 2.2 times of Ta3N5/CdS. The proper capacitance and enhanced activity of Ta3N5demonstrates the capacitance catalysis effect of Ta3N5, which improves the charges separation and storing of the photoexcited electrons from CdS. Au acts as an active site for proton reduction to further improve the activity.Keywords:co-catalyst;Ta3N5;capacitance catalysis;photocatalytic hydrogen production

Constructed CdS/Mn-MOF heterostructure for promoting photocatalytic degradation of Rhodamine B

Cai-Yong Zhu,Meng-Ting Shen,Meng-Jie Qi,Ya-Yu Zhao,Zhen Xu,Peng Li,Jie Ru,Wei Gao,Xiu-Mei Zhang

A new 3D Mn-MOF was prepared with the ligand H 2 L (H 2 L = 5-(pyrazin-2-yl) isophthalic acid) by solvothermal method. Then the Mn-MOF was used as a precursor to synthesize CdS/Mn-MOF composites. The degradation efficiency of Rhodamine B (RhB) by CdS/Mn-MOF (theoretical mass ratio of CdS to Mn-MOF is 1:1) is 98.7% in 60 min, which is 19.7 times and 2.3 times that of Mn-MOF and CdS, respectively. The outstanding performance is owed to the loading of CdS, which significantly broadens the photoresponsive range of Mn-MOF and improves the utilization of visible light. Meanwhile, the heterojunction formed between Mn-MOF and CdS can effectively inhibit the recombination of photogenerated electrons and holes. Furthermore, the photocurrent intensity of CdS/Mn-MOF(50) is higher than that of Mn-MOF and CdS. The photocatalytic performance of CdS/Mn-MOF(50) also exhibits excellent stability and reusability . In addition, the enhanced mechanism of photocatalytic activity was investigated systematically.

Evolutionary mechanism of Ni-ZIF/CdS calcination for efficient photocatalytic hydrogen evolution

Jinxiao Ba,Hui Cheng,Zhenhan Li,Xianghai Yu,Aiying Song,Chengqun Xu,Donghua Fan,Shengye Jin

In this work, we develop Ni/Ni 3 S 2 /CdS composite photocatalytic system from annealing of CdS nanosphere coated Ni-ZIF by simple solvothermal method. The Ni/Ni 3 S 2 /CdS synthesized after calcination at 700 °C exhibits the best hydrogen evolution performance with an average hydrogen evolution rate of 2104.02 μmol/g/h, which is 152 times higher than that of pure CdS, and external quantum efficiency is 41.9% (λ = 420 nm). Using a series of characterization methods, we revealed that CdS is the photosensitizer, Ni is the catalytic active species, and Ni 3 S 2 formed between Ni and CdS formation plays an important role in charge separation as confirmed by time resolved emission spectroscopy. In addition, the regulation of Ni loading is achieved by changing the annealing time and the molar ratio of Ni salt to CdS. These results demonstrate that Ni/Ni 3 S 2 /CdS is a favorable photocatalyst for efficient photocatalytic hydrogen evolution.