pH值调节方式对LAB辅助合成纳米Cu2O微球的影响与组装机理

以Cu(Ac)₂为原料,两性表面活性剂月桂酰胺丙基甜菜碱(LAB)为模板,采用两种不同的调节pH值方式制备了Cu₂O纳米材料.表征结果表明两种调节pH值方式均可获得Cu₂O纳米微球,并都呈立方晶相,而且样品的红外吸收峰、固体紫外吸收峰都不同程度的发生了蓝移;第一种Cu₂O纳米微球由针状纳米粒子积聚而成,针状纳米粒子间空隙孔径主要分布在25~50 nm之间,比表面积为22 m²·g^-1,禁带宽度为2.15 eV;第二种Cu₂O纳米微球由小的纳米球状体堆积而成,球状体间孔道直径集中在25~50 nm和50~125 nm两个区域,比表面积为9 m²·g^-1,禁带宽度为2.46 eV.两种不同的调节pH值方式获得的Cu₂O纳米微球,其反应历程和自组装机理存在不同.     

基于金纳米棒刻蚀比色法检测铁、铜离子

采用种子生长法制备金纳米棒(AuNRs)以构建光学传感器,用于 Fe³⁺和 Cu²⁺的高选择性快速可视化检测。在酸性环境中,Fe³⁺和 Cu²⁺通过与 KI溶液反应,将 I^-氧化成 I₂。I₂刻蚀 AuNRs,导致其纵向表面等离子体共振(LSPR)吸收峰蓝移,从而实现对Fe³⁺和Cu²⁺的检测。结果表明,反应温度为50℃时,添加0.8 mL 0.1 mol·L^-1 HCl、2 mL AuNRs生长液和20 mmol·L^-1 KI溶液,与 2 mL 500 μmol·L^-1 Fe³⁺或 30 μmol·L^-1 Cu²⁺反应 25或 90 min,可将 AuNRs刻蚀至 LSPR 吸收峰消失。该方法对 Fe³⁺和 Cu²⁺检测具有高选择性和准确性,对于 Fe³⁺、Cu²⁺共存体系的检测,可通过加入适量 F-与 Fe³⁺生成配合物[FeF₆]3^-完成对 Fe³⁺的化学掩蔽,消除Fe³⁺的干扰,实现共存体系中Cu²⁺的准确检测。     

改性PTFE纤维金属配合物的制备及其光催化降解性能

使用聚丙烯酸接枝改性聚四氟乙烯(PAA-g-PTFE)纤维分别与Fe³⁺及其与Cu²⁺的混合物反应制备改性PTFE纤维铁和铁铜双金属配合物, 并分别使用傅里变换叶红外(FTIR)光谱和紫外-可见(UV-Vis)漫反射光谱(DRS)对两种配合物的化学结构和光吸收性能进行表征. 然后将两种配合物分别作为非均相光Fenton 反应催化剂应用于典型偶氮染料活性蓝222氧化降解反应中, 考察和比较了二者在不同pH介质中对降解反应的催化作用. 结果表明, 在有或无Cu²⁺的存在条件下, 一个Fe³⁺能够与三个PAA-g-PTFE表面的6个羧基发生反应形成配合物, 并且它们在紫外和可见光区表现出好的光吸收特性. 当两种金属离子共存时Cu²⁺比Fe³⁺更容易与PAA-g-PTFE发生配位反应形成铁铜双金属配合物. 在可见光辐射下PAA-g-PTFE铁配合物对不同pH水溶液中染料降解反应均表现出显著的催化作用, 但是溶液pH的升高不利于配合物催化活性的发挥. 而配合物中铁离子含量提高特别是引入Cu²⁺作为助金属离子能够较大幅度地改善其在高pH范围内的催化活性和重复利用性.     

多元醇法制备Cu2O/CNTs复合材料的研究

以Cu(CH₃COO)₂•H₂O和经硝酸处理的CNTs作为原料, 采用多元醇法成功合成了纳米氧化亚铜均布于碳纳米管表面的复合光催化剂. 用透射电镜(TEM), 高分辨透射电镜(HRTEM), X射线粉末衍射(XRD)对样品进行了表征, 测试结果表明大小为2～5 nm的氧化亚铜纳米颗粒均匀分散于碳纳米管的表面. 讨论了反应条件对Cu₂O在CNTs上负载效果的影响并就多元醇法合成Cu₂O/CNTs复合材料的反应机理作了初步探讨.     

多元醇法制备Cu2O/CNTs复合材料的研究

以Cu(CH₃COO)₂•H₂O和经硝酸处理的CNTs作为原料, 采用多元醇法成功合成了纳米氧化亚铜均布于碳纳米管表面的复合光催化剂. 用透射电镜(TEM), 高分辨透射电镜(HRTEM), X射线粉末衍射(XRD)对样品进行了表征, 测试结果表明大小为2～5 nm的氧化亚铜纳米颗粒均匀分散于碳纳米管的表面. 讨论了反应条件对Cu₂O在CNTs上负载效果的影响并就多元醇法合成Cu₂O/CNTs复合材料的反应机理作了初步探讨.     

α-Fe2O3、γ-Al2O3、SiO2混合体系的表面配位反应

运用自动电位滴定技术分别研究了纳米α-Fe₂O₃、γ-Al₂O₃、SiO₂单一体系及三组分混合体系中氧化物表面的酸碱性质和对重金属离子Cu²⁺、Pb²⁺、Zn²⁺的吸附行为. 依据表面配位理论恒电容模式(CCM), 计算了相应的表面酸碱配位常数. 结果表明: α-Fe₂O₃/γ-Al₂O₃/SiO₂三组分混合体系的表面化学反应并非是单一体系的简单叠加, 而是存在着不同矿物表面间复杂的交互作用. 三组分表面酸碱反应平衡式和相应的酸碱反应平衡常数分别为: ≡XOH₂⁺?≡XOH+H⁺ (lgK_a1=-4.23), ≡XOH?≡XO^-+H⁺(lgK_a2=-8.41). 根据重金属离子Cu²⁺、Pb²⁺、Zn²⁺在α-Fe₂O₃/γ-Al₂O₃/SiO₂混合体系表面的吸附行为, 计算得到Cu²⁺、Pb²⁺、Zn²⁺在混合体系表面配位反应及其平衡常数如下: ≡XOH＋M²⁺?≡XOM⁺+H⁺; lgK=-2.20, -1.90, -3.20 (M=Cu, Pb, Zn).     

N-乙基咔唑-3-甲醛席夫碱荧光探针的合成及其检测Cu2+性质

以咔唑为原料,经过两步反应制备得到N-乙基咔唑-3-甲醛,其结构经X射线单晶衍射测定属于单斜晶系,空间群为P2₁/n。再以N-乙基咔唑-3-甲醛与1,3-二氨-2-丙醇为原料,设计、合成了一种新型双席夫碱荧光探针分子CMP。借助荧光光谱在体积比为6∶4的DMSO/H₂O缓冲溶液(Tris-HCl,pH=7.0)中研究了探针CMP对Cu²⁺的选择性识别。研究结果表明,探针CMP与Cu²⁺以1∶2的比例配位,结合常数为1.52×10⁵ L·mol^-1,检出限为0.205 μmol·L^-1。回收实验表明,探针分子CMP可应用于环境水样中Cu²⁺的检测。     

气相中Cu+和Zn+与CS2反应的计算研究

以Cu⁺和Zn⁺与CS₂反应作为第一过渡金属离子与CS₂反应的范例体系. 采用密度泛函UB3LYP/6-311+G^*方法计算研究了第一过渡金属离子在基态和激发态与CS₂反应的反应机理. 全参数优化了反应势能面上各驻点的几何构型, 用频率分析方法和内禀反应坐标(IRC)方法对过渡态进行了验证. 并用UCCSD(T)/6-311G^*方法对各驻点作了单点能量校正. 在Cu⁺与CS₂反应中, 计算了单重态初始中间体¹IM1到三重态插入型中间体³IM2的反应交叉势能面. 确定了第一过渡金属离子与CS₂的反应为插入-消去反应, 找到了基态和激发态金属离子与CS₂反应的主要通道.     

SILAR法制备化学计量CuInS2薄膜

在室温下，以不同c_Cu/c_In的CuCl₂和InCl₃混合溶液作为阳离子前驱体，Na₂S水溶液为硫源，利用连续离子层吸附反应法(SILAR)在玻璃基底上制备了CuInS₂薄膜。XRD结果表明，当c_Cu²⁺/c_In³⁺在1～1.5范围内均可形成具有黄铜矿结构的CuInS₂薄膜。SEM观察到随c_Cu²⁺/c_In³⁺的升高，薄膜表面颗粒长大并出现团簇聚集。通过XPS测定薄膜表面的化学组成证明当c_Cu²⁺/c_In³⁺=1.25时，CuInS₂薄膜接近其标准的化学计量组成。此时薄膜的吸收系数大于>10⁴ cm^-1，禁带宽度E_g为1.45 eV。     

负载型纳米二氧化钛对重金属离子吸附性能的研究

采用溶胶-凝胶法制备二氧化钛溶胶, 将其浸渍在硅胶上, 合成了负载型纳米二氧化钛材料, 以X射线衍射(XRD)、扫描电镜(SEM)等手段对其进行了表征. 以ICP-AES为检测手段, 系统地研究了负载型纳米TiO₂材料对重金属离子Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的吸附性能. 结果表明, 在pH 8～9范围内, 所研究的重金属离子均可被定量富集, 吸附的金属离子可用0.5 mol/L的HNO₃完全解脱. 负载型纳米二氧化钛对Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的静态吸附容量分别为8.3, 13.1, 12.6和5.1 mg/g, 与未负载的纳米二氧化钛相近. 将其应用于环境标准样品中Cd^2＋, Cr^3＋, Cu^2＋和Mn^2＋的分离富集与测定, 结果满意.     

Sr14-xCaxCu24O41的芯能级光电子发射谱

The core-level X-ray photoelectron emission spectra of the quasi-one dimensional spin 1/2 antiferromagnetic system Sr14-xCaxCu24O41(x=0, 3.5, 6, 7, 8.4) were measured. The main peak of Cu2p3/2 was about 933.8 eV, and the full width of half maximum height was about 3.3 eV. Simulation of Cu2p3/2 by XPSPEAK41 shows that the percents of Cu2+ and Cu3+ in Sr14Cu24O41 are 92.13% and 7.87%, no obvious change to Cu2p core-level is observed by the partial substituting Ca for Sr, and the average valence of Cu in this system is estimated to be 2.08. The main peak of O1s is about 531.0 eV, and the weak shoulder toward the low binding energy direction can be considered as the contribution of Ca-O bond. The binding energies of Ca2p3/2 and Sr3d5/2 indicate that their valence in this system are both +2, without mixed valence.     

LnCu2O4(Ln=Gd,Nd)电子结构的XPS研究

用XPS测定了LnCu2O4(Ln=Gd, Nd)的内层和价层电子能谱,观察到LnCu2O4中稀土金属的3d电子结合能比相应的稀土金属简单氧化物的3d结合能低0.8～0.9 eV,而Cu的2p电子结合能比CuO的高0.4～0.5 eV,因此推断在LnCu2O4的Ln－O－Cu链中存在Cu→O→Ln电荷转移.XPS分析还表明LnCu2O4的Cu原子上有较低的电荷密度,但不存在混合价态.此外,通过比较价电子能谱,发现NdCu2O4的Ln 4f Cu 3d O 2p价带中心比GdCu2O4的价带中心向Fermi能级移近了3.4 eV,而且NdCu2O4的价带谱更窄.     

Interactions of selenate with copper(I) oxide particles

The chemical mechanisms responsible for the immobilization of selenate (SeO4(2-) from aqueous solutions on cuprite (Cu2O) particles were determined from batch experiments. This was achieved by performing both solution-phase analyses and characterization of solid particles by X-ray photoelectron spectroscopy and transmission electron microscopy techniques, after equilibration of cuprite particles with selenate-containing solutions at various pH values, solid-to-solution ratios, and ionic strengths. Two distinct mechanisms have been pointed out. In the acidic medium, where the acid-catalyzed dissolution of cuprite into CuI species occurs, the immobilization of selenate implies a redox reaction with transient CuI leading to the precipitation of copper(II) selenite, CuSeO3. In the absence of protons added in the medium, Cu2O is chemically stable and immobilization of SeO4(2-) is essentially due to adsorption in the form of an outer-sphere surface complex. The uptake level of selenate by Cu2O is markedly lower than that observed for selenite species in the same conditions.     

Thermoluminescent response of LiF : Mg,Cu,P+PTFE prepared in Mexico to Sr/Y beta particles

Results of study of the thermoluminescent response of LiF : Mg,Cu,P+PTFE irradiated with beta particles are presented and compared with results for LiF TLD-100. Both materials exhibited a linear dose response in the range from 4.35 mGy to 2.17519 Gy. The glow curve of LiF : Mg,Cu,P+PTFE exhibited four peaks while TLD-100 showed six. All the peaks studied for the two materials exhibited first order kinetics. The average values of activation energy were: 1.35, 1.58 and 2.51 eV for LiF : Mg,Cu,P+PTFE; and, 2.04, 2.24, 2.51 and 2.89 eV for LiF TLD-100.     

Highly mixed phases in ball-milled Cu/ZnO catalysts: an EXAFS and XANES study

New highly mixed phases have been identified in Cu/ZnO systems by EXAFS and XANES at both the Cu and Zn K-edge. The phases were generated by ball-milling Cu(2)O/ZnO mixtures under three different atmospheres of synthetic air (SA), SA + CO(2) and CO(2). The system milled in CO(2) shows disproportionation of Cu(2)O into Cu(0), Cu(1+) (cuprite Cu(2)O-type phase) and Cu(2+) (tenorite CuO-type phase), while most of the Zn(2+) is transformed into a nanocrystalline/amorphous ZnO-type zincite that forms a superficial mixture of oxide and carbonate phases. When synthetic air is added to the CO(2) atmosphere, ball milling results in the oxidation of nearly half the Cu(1+) into Cu(2+) with no Cu metal formed. The copper phase in this material is almost entirely amorphous. In SA, a significant amount of Cu(2+)- and Zn(2+)-based phases appears to react to form a nanocrystalline/amorphous Cu(1-x)Zn(x)O (x approximately 0.3) solid solution. This distorted rock saltlike solid solution, in which Zn and Cu feature different octahedral environments, was never reported before. It is thought to be formed by incorporation of Zn(2+) in the Cu fcc sublattice of the cuprite Cu(2)O matrix and the concomitant oxidation of Cu(1+) into Cu(2+). The formation of such a highly mixed Cu(1-x)Zn(x)O phase indicates strong Cu/Zn interaction in the Cu/ZnO system, which also suggests the presence of highly mixed phases in conventionally prepared activated catalysts.     

Deposition of CuInS2 thin films using copper- and indium/sulfide-containing precursors through a two-stage MOCVD method

Copper indium disulfide (CuInS2; CIS) films were deposited on various substrates by two-stage metal-organic chemical vapor deposition (MOCVD) at relatively mild conditions, using Cu- and In/S-containing precursors without toxic H2S gas: first, a pure Cu thin film was prepared on glass or indium/tin oxide glass substrates by using a single-source precursor, bis(ethylbutyrylacetato)copper(II) or bis(ethylisobutyrylacetato)copper(II); second, on the resulting Cu film, tris(N,N-ethylbutyldithiocarbamato)indium(III) was treated to produce CIS films by a MOCVD method at 430 degrees C. In this process, their thicknesses and stoichiometries were found to be elaborately controlled on demand by adjusting the process conditions. The optical band gap of the stoichiometric CIS film was about 1.41 eV, which is in the near-optimal range for harvesting solar radiation energy.     

花状铜锌锡硫纳米颗粒的溶剂热法制备和结构表征

以金属氯化物为金属源,硫脲为硫源,聚乙二醇和乙二醇为混合溶剂,采用溶剂热法一步合成了花状的铜锌锡硫纳米颗粒.利用X射线衍射仪,扫描电子显微镜、能谱仪、透射电子显微镜、紫外-可见分光光度计分析了铜锌锡硫纳米颗粒的物相、结构、形貌及光学性能,并初步探讨了铜锌锡硫的生长机理.结果表明,所得到的铜锌锡硫纳米颗粒具有锌黄锡矿结构,直径在500～2 000nm范围内可调,其中花状的铜锌锡硫纳米颗粒由大量厚度约25nm的纳米片构成.所制备的铜锌锡硫纳米颗粒对可见光具有明显的吸收;利用外延法推算得到其禁带宽度约为1.5eV,与太阳能电池所需的最佳禁带宽度相近,显示其有望在新一代太阳能电池中得到应用和推广.     

氢原子吸附的Cu(100)表面原子结构和电子态

用密度泛函理论的总能计算研究了金属铜(100)面的表面原子结构以及在不同覆盖度时氢原子的吸附状态. 研究结果表明, 在Cu(100)c(2×2)/H表面体系中, 氢原子吸附的位置是在空洞位置, 距最外层Cu原子层的距离为0.052 nm, 相应的Cu—H键长为0.189 nm, 并通过计算结构参数优化否定了其它的吸附位置模型. 总能计算得出Cu(100)c(2×2)/H表面的功函数为4.47 eV, 氢原子在这一体系的吸附能为2.37 eV(以孤立氢原子为能量参考点). 通过与衬底原子的杂化, 氢原子形成了具有二维特征的氢能带结构, 在费米能级以下约0.8 eV处出现的表面局域态是Cu(S)-H-Cu(S-1)型杂化的结果. 采用Cu(100)表面p(1×1)、p(2×2)和p(3×3)的三种氢吸附结构分别模拟1, 1/4, 1/9的原子单层覆盖度, 计算结果表明, 随着覆盖度的增加, 被吸附的氢原子之间的距离变短, 使得它们之间的静电排斥和静电能增大, 从而导致表面吸附能和吸附H原子与最外层Cu原子间垂直距离(ZH-Cu)逐渐减小. 在较低的覆盖度下, 氢原子对Cu(100)表面的影响主要表现为单个原子吸附作用的形式. 通过总能计算还排除了Cu(100)表面(根号2×2根号2)R45°-2H缺列再构吸附模型的可能性.     

DFT study of gas-phase adsorption of benzotriazole on Cu(111), Cu(100), Cu(110), and low coordinated defects thereon

The adsorption of benzotriazole--an outstanding corrosion inhibitor for copper--on Cu(111), Cu(100), Cu(110), and low coordinated defects thereon has been studied and characterized using density functional theory (DFT) calculations. We find that benzotriazole can either chemisorb in an upright geometry or physisorb with the molecular plane being nearly parallel to the surface. While the magnitude of chemisorption energy increases as passing from densely packed Cu(111) to more open surfaces and low coordinated defects, the physisorption energy is instead rather similar on all three low Miller index surfaces. It is pointed out that due to a large dipole moment of benzotriazole the dipole-dipole interactions are rather important. For perpendicular chemisorption modes the lateral repulsion is very long ranged, extending up to the nearest-neighbor distance of about 60 bohrs, whereas for parallel adsorption modes the lateral interactions are far less pronounced and the molecules experience a weak attraction at distances ?25 bohrs. The chemisorption energies were therefore extrapolated to zero coverage by a recently developed scheme and the resulting values are -0.60, -0.73, and -0.92 eV for Cu(111), Cu(100), and Cu(110), respectively, whereas the zero-coverage physisorption energy is about -0.7 eV irrespective of the surface plane. While the more densely packed surfaces are not reactive enough to interact with the molecular π-system, the reactivity of Cu(110) appears to be at the onset of such interaction, resulting in a very stable parallel adsorption structure with an adsorption energy of -1.3 eV that is ascribed as an apparent chemisorption+physisorption mode.     

Design of energy band alignment at the Zn(1-x)Mg(x)O/Cu(In,Ga)Se2 interface for Cd-free Cu(In,Ga)Se2 solar cells

The electronic band structure at the Zn(1-x)Mg(x)O/Cu(In(0.7)Ga(0.3))Se(2) interface was investigated for its potential application in Cd-free Cu(In,Ga)Se(2) thin film solar cells. Zn(1-x)Mg(x)O thin films with various Mg contents were grown by atomic layer deposition on Cu(In(0.7)Ga(0.3))Se(2) absorbers, which were deposited by the co-evaporation of Cu, In, Ga, and Se elemental sources. The electron emissions from the valence band and core levels were measured by a depth profile technique using X-ray and ultraviolet photoelectron spectroscopy. The valence band maximum positions are around 3.17 eV for both Zn(0.9)Mg(0.1)O and Zn(0.8)Mg(0.2)O films, while the valence band maximum value for CIGS is 0.48 eV. As a result, the valence band offset value between the bulk Zn(1-x)Mg(x)O (x = 0.1 and x = 0.2) region and the bulk CIGS region was 2.69 eV. The valence band offset value at the Zn(1-x)Mg(x)O/CIGS interface was found to be 2.55 eV after considering a small band bending in the interface region. The bandgap energy of Zn(1-x)Mg(x)O films increased from 3.25 to 3.76 eV as the Mg content increased from 0% to 25%. The combination of the valence band offset values and the bandgap energy of Zn(1-x)Mg(x)O films results in the flat (0 eV) and cliff (-0.23 eV) conduction band alignments at the Zn(0.8)Mg(0.2)O/Cu(In(0.7)Ga(0.3))Se(2) and Zn(0.9)Mg(0.1)O/Cu(In(0.7)Ga(0.3))Se(2) interfaces, respectively. The experimental results suggest that the bandgap energy of Zn(1-x)Mg(x)O films is the main factor that determines the conduction band offset at the Zn(1-x)Mg(x)O/Cu(In(0.7)Ga(0.3))Se(2) interface. Based on these results, we conclude that a Zn(1-x)Mg(x)O film with a relatively high bandgap energy is necessary to create a suitable conduction band offset at the Zn(1-x)Mg(x)O/CIGS interface to obtain a robust heterojunction. Also, ALD Zn(1-x)Mg(x)O films can be considered as a promising alternative buffer material to replace the toxic CdS for environmental safety.