Multifunctional MoS2 ultrathin nanoflakes loaded by Cd0.5Zn0.5S QDs for enhanced photocatalytic H2 production

Two‐dimensional MoS₂ has been widely used as hydrogen evolution reaction (HER) cocatalyst to load onto nanostructured semiconductors for visible light‐response photocatalytic hydrogen production. However, its another important role as light harvester because of the band‐gap tunable property and beneficial band position has been rarely exploited. Herein, few layer‐thick MoS₂ nanoflakes with extended light absorption over the range of 400 to 680 nm and a photocatalytic HER rate of 0.98 mmol/h/g have been obtained. Then 7‐nm‐sized Cd_0.5Zn_0.5S quantum dots (QDs) are selectively grown upon ultrathin MoS₂ nanoflakes for enhanced photocatalytic H₂ generation. Upon the photocatalytic, light absorption, and charge transfer properties of the MoS₂‐Cd_0.5Zn_0.5S composites evolved with the amount of MoS₂ from 0 to 3 wt%, the multiple roles of MoS₂ as long‐wavelength light absorber, in‐plane carrier mediator, and edge site‐active HER catalyst have been revealed. An optimum H₂ generation rate of 8863 μmol/h/g and a solar to hydrogen (STH) efficiency of 2.15% have been achieved for 2 wt% MoS₂‐Cd_0.5Zn_0.5S flakes. Such a strategy can be applied to other cocatalysts with both the light response and HER activity for efficient photocatalytic property.     

Tumor‐Targeted Multimodal Optical Imaging with Versatile Cadmium‐Free Quantum Dots

The rapid development of fluorescence imaging technologies requires concurrent improvements in the performance of fluorescent probes. Quantum dots have been extensively used as an imaging probe in various research areas because of their inherent advantages based on unique optical and electronic properties. However, their clinical translation has been limited by the potential toxicity especially from cadmium. Here, a versatile bioimaging probe is developed by using highly luminescent cadmium‐free CuInSe₂/ZnS core/shell quantum dots conjugated with CGKRK (Cys–Gly–Lys–Arg–Lys) tumor‐targeting peptides. This probe exhibits excellent photostability, reasonably long circulation time, minimal toxicity, and strong tumor‐specific homing property. The most important feature of this probe is that it shows distinctive versatility in tumor‐targeted multimodal imaging including near‐infrared, time‐gated, and two‐photon imaging in different tumor models. In a glioblastoma mouse model, the targeted probe clearly denotes tumor boundaries and positively labels a population of diffusely infiltrating tumor cells, suggesting its utility in precise tumor detection during surgery. This work lays a foundation for potential clinical translation of the probe.     

Cd_(1-x)Zn_xTe多晶薄膜的制备、性能与光伏应用

用共蒸发法制备了 Cd1 - x Znx Te多晶薄膜 ,薄膜结构属立方晶系空间群 F4 3m.通过透射光谱的测量 ,计算光能隙 ,得到室温时薄膜的光能隙随组分 x值的变化满足二次方关系 .作为对异质结界面的修饰 ,提出了有 Cd1 - x-Znx Te过渡层的 Cd S/ Cd Te/ Cd1 - x Znx Te/ Zn Te∶ Cu电池 .并在相同工艺下制备了 Cd S/ Cd Te/ Cd0 .4 Zn0 .6 Te/ Zn Te∶ Cu与 Cd S/ Cd Te/ Zn Te∶ Cu太阳电池 ,发现前者比后者效率平均增加了 35 .0 % .     

(Zn,Cd)S porous layers for dye-sensitized solar cell application

Porous (Zn,Cd)S structures were formed by screen printing of CdS, ZnS, ZnCl₂ and CdCl₂ powders in different configurations and sintering in air at high temperature. The XRD (X-ray diffraction) analysis of these layers sintered at different temperatures revealed that the CdO and ZnO formation in the (Zn,CdS) matrix is by the phase transformation of (Zn,Cd)S. The structure, composition and photosensitivity of this composite structure depends on the sintering temperature, sintering atmosphere and the flux to semiconductor (F/S) ratio. The results indicate that the screen printed (Zn,Cd)S structure may be used as a photoconductor in solid state devices and as a photoelectrode in photo-electro-chemical energy conversion systems.     

有机肥和生态肥对土壤中镉行为以及水稻生长的影响

通过水稻盆栽试验,研究了有机肥和生态肥对镉污染土壤上水稻生长和土壤中镉形态变化的影响,以及对改善糙米品质安全性的作用。结果表明,有机肥和生态肥因性质差异,其效果不尽相同。和有机肥相比,生态肥不仅在促进水稻生长、提高水稻产量方面的作用更加显著,而且在降低土壤中有效态镉以及糙米、茎叶和水稻根中镉含量的作用效果更好。施用生态肥和有机肥使水稻体内镉含量和土壤中有效态镉含量的降低,主要是由于施用不同肥料导致的土壤中镉形态的变化。     

On the complex formation of CdCl2 with 1-furoylthioureas: Preconcentration and voltammetric behavior of Cd(II) at carbon paste electrodes modified with 3-monosubstituted and 3,3-disubstituted derivatives

Two series of 1-furoylthioureas were used as modifiers of carbon paste electrodes (CPE). The preconcentration of Cd(II) at CPE modified with these 3-monosubstituted and 3,3-disubstituted 1-furoylthioureas and its subsequent voltammetric determination was studied with Cd(II) test solution. The preconcentration of cadmium at the surface of the modified CPE varied with the steric and electronic nature of the present CS neighboring groups. This is in accord with the changes observed in the Raman spectra of the ligands after complexation with CdCl₂, and with the chemical yields of the complexes obtained.     

Structure evolution on annealing of copper-doped carbon film

Thin copper-doped (8 at.% Cu) carbon film was deposited by direct current magnetron sputtering of composite graphite/copper target in argon plasma. The evolution of film structure on annealing at 600 °C in a vacuum has been studied by transmission electron microscopy and electron diffraction. The as-deposited film was amorphous with copper atoms uniformly distributed over the film volume. Annealing resulted in precipitation of copper particles within carbon film followed by the decrease in the density of copper particles and increase in particle average size with annealing time due to diffusion coalescence within the ensemble of copper particles. The coalescence occurred by the mixed mechanism of bulk and surface diffusion of copper atoms within carbon film that contained a large number of structural defects. As a result, the mean radius of copper particles in ensemble changed as R¯⁵ ∼ t.     

电沉积法制备加速器生产109Cd用Ag靶

采用电沉积法对加速器生产109Cd所用Ag靶的制备工艺进行研究。实验研究了电沉积过程中影响Ag靶层质量及厚度的主要因素,确定了Ag靶制备工艺条件和工艺参数:ρ(Ag )=20~50 g/L,ρ(KNO3)=10~30 g/L,φ(NH4OH)=0.1~0.2;电流密度10~15 mA/cm2,电沉积时间2~3 h,室温。用此工艺条件制备出靶厚大于100 mg/cm2、表面光滑、镀层致密的Ag靶。     

Interfacial Chemical Bond and Oxygen Vacancy-Enhanced In2O3/CdSe-DETA S-scheme Heterojunction for Photocatalytic CO2 Conversion

The S-scheme heterojunctions have great potential for photocatalytic carbon dioxide reduction due to their unique carrier migration pathways, superior carrier separation efficiencies, and high redox capacities. However, the precise process of the oriented powerful electron transport remains a great challenge. Herein, an In O Cd bond-modulated S-scheme heterojunction of In₂O₃/CdSe-DETA is synthesized by a simple microwave-assisted hydrothermal method for the accelerated photogenerated electron transfer. Meanwhile, the oxygen vacancies (Vo) of In₂O₃ have an electron capture effect. Consequently, thanks to the synergistic effect of this In-Vo-In-O-Cd structural units at the interface, electrons are extracted and rapidly transferred to the surface-active sites, which improves the electronic coupling of CO₂. This finding precisely adjusts the electron transfer pathway and shortens the electron transfer distance. The synergistic effect of this chemical bond established in the S-scheme heterostructure with oxygen vacancies in In₂O₃ (Vo-In₂O₃) provides new insights into photocatalytic CO₂ reduction.     

The TiO2/Mn0.2Cd0.8S hollow heterojunction with Mn/Cd bimetallic synergy towards photocatalytic hydrogen production enhancement

The TiO₂/Mn_0.2Cd_0.8S hollow heterojunction with Mn/Cd bimetallic synergy is prepared via a continuous chemical-hydrothermal-etching method. There, the TiO₂ shell and Mn_0.2Cd_0.8S nanoparticles were deposited by continuous chemical-hydrothermal method on the surface of SiO₂ template, and subsequently the SiO₂ template was etched via a chemical method. Evaluated by HER, the as-prepared TiO₂/Mn_0.2Cd_0.8S hollow heterojunction exhibits an obvious photocatalytic enhancement to about ~5822.94 μmol/g∙h(~40 folds of TiO₂, ~7 folds of Mn_0.2Cd_0.8S), which can be mainly ascribed to that, the narrow band gap of Mn_0.2Cd_0.8S can increase the visible light energy utilization, the TiO₂/Mn_0.2Cd_0.8S heterojunction and Mn/Cd bimetallic synergy can separate/transfer the photo-generated charge carriers efficiently, and the sufficient specific surface areas and actives from 3D hollow structure can promote the charge carrier diffusing into water quickly for achieving H₂ generation. Additionally, the hollow 3D structure can provide a decent physical-chemical stability to improve the photocatalytic stability.