真空紫外协同Co^(2+)催化过硫酸氢钾降解罗丹明B

有机染料具有毒性强、色度高、不易降解等特性,为了高效去除有机染料,实验以真空紫外(VUV)为光源,研究了VUV协同Co^(2+)催化过硫酸氢钾(PMS)降解典型有机染料罗丹明B(RhB)的反应机制和转化途径.结果表明:①在RhB初始浓度为80 mg/L,Co^(2+)和PMS投加量分别为15μmol/L、0.5 mmol/L的条件下,VUV/Co^(2+)/PMS体系反应10 min,RhB去除率可达99.1%.VUV/Co^(2+)/PMS体系对RhB降解遵循一级动力学规律,反应速率常数(k)随初始质量浓度的增加而减小.②溶液初始pH对反应速率有较大的影响,随着pH减小,反应速率也同时减小.投加量为30 mmol/L的HCO_(3)^(−)、Cl^(−)均表现出显著的抑制作用,相较于对照组,RhB去除率由99.1%分别降至66.0%、84.2%,而NO_(3)^(−)和SO_(4)^(2−)抑制作用不显著;印染助剂柠檬酸钠也会显著抑制RhB降解.③自由基捕获实验和电子顺磁共振(EPR)测试结果表明,VUV/Co^(2+)/PMS体系中存在的氧化物种包括硫酸根自由基(SO_(4)^(−)·)、羟基自由基(·OH)、单线态氧(1O2).④根据紫外可见吸收光谱和质谱结果,初步推断RhB分子降解主要通过活性氧(ROS)攻击造成共轭结构破坏和N-位脱乙基等作用.另外,对总有机碳(TOC)进行测试,30 min时RhB矿化度可达到43.8%.研究显示,VUV/Co^(2+)/PMS体系能够有效去除RhB.

Fabrication of Gd_(2)O_(3)-doped CeO_(2)thin films through DC reactive sputtering and their application in solid oxide fuel cells

Physical vapor deposition(PVD)can be used to produce high-quality Gd_(2)O_(3)-doped CeO2(GDC)films.Among various PVD methods,reactive sputtering provides unique benefits,such as high deposition rates and easy upscaling for industrial applications.GDC thin films were successfully fabricated through reactive sputtering using a Gd_(0.2)Ce_(0.8)(at%)metallic target,and their application in solid oxide fuel cells,such as buffer layers between yttria-stabilized zirconia(YSZ)/La0.6Sr0.4Co0.2Fe0.8O_(3−δ)and as sublayers in the steel/coating system,was evaluated.First,the direct current(DC)reactive-sputtering behavior of the GdCe metallic target was determined.Then,the GDC films were deposited on NiO-YSZ/YSZ half-cells to investigate the influence of oxygen flow rate on the quality of annealed GDC films.The results demonstrated that reactive sputtering can be used to prepare thin and dense GDC buffer layers without high-temperature sintering.Furthermore,the cells with a sputtered GDC buffer layer showed better electrochemical performance than those with a screen-printed GDC buffer layer.In addition,the insertion of a GDC sublayer between the SUS441 interconnects and the Mn-Co spinel coatings contributed to the reduction of the oxidation rate for SUS441 at operating temperatures,according to the area-specific resistance tests.

不同条件下Co^(2+)对锌电积的影响

Co^(2+)是湿法炼锌中重点关注的有害杂质之一。以含Co^(2+)的硫酸锌溶液作为模拟研究对象,整体研究含Co^(2+)的硫酸锌溶液中分别存在松醇油和Mg^(2+)时,Co^(2+)对锌电解的影响行为。结果表明,当电积液中不存在松醇油和Mg^(2+)时,Co^(2+)的存在造成了锌板的穿孔,出现了轻微“烧板”现象,需要将电积液中Co^(2+)浓度控制在0.6 mg/L以下。当电积液中加入0.21 g/L的松醇油时,Co^(2+)的含量对锌电积的不利影响比电积液中不存在松醇油时的影响更大,需要将电积液中Co^(2+)浓度控制在0.4 mg/L以下。当Mg^(2+)浓度分别为5 g/L和10 g/L时,需要将电积液中Co^(2+)浓度控制在0.4 mg/L和0.2 mg/L以下。当Mg^(2+)浓度为15 g/L时,电积液中的Co^(2+)应尽量除尽。

Cu^(2+)和Co^(2+)促进芬顿氧化处理垃圾渗滤液的研究

通过在传统芬顿体系中加入Cu^(2+)、Co^(2+),研究Cu^(2+)/Co^(2+)/Fe^(2+)/H_(2)O_(2)、Cu^(2+)/Fe^(2+)/H_(2)O_(2)、Co^(2+)/Fe^(2+)/H_(2)O_(2)和Fe^(2+)/H_(2)O_(2)四种芬顿体系对垃圾渗滤液的处理效果,发现当初始pH分别为2、3、4、5、6时,各体系去除COD_(Cr)的效果排序为Cu^(2+)/Co^(2+)/Fe^(2+)/H_(2)O_(2)>Cu^(2+)/Fe^(2+)/H_(2)O_(2)>Co^(2+)/Fe^(2+)/H_(2)O_(2)>Fe^(2+)/H_(2)O_(2),Cu^(2+)、Co^(2+)对芬顿反应效果的提升具有促进作用;Cu^(2+)/Co^(2+)/Fe^(2+)/H_(2)O_(2)和Cu^(2+)/Fe^(2+)/H_(2)O_(2)体系比传统芬顿体系具有更宽的pH响应范围;Cu^(2+)、Co^(2+)的引入明显加快芬顿反应速率,反应时间可由3h缩短至2h。在Cu^(2+)/Co^(2+)/Fe^(2+)/H_(2)O_(2)体系中,m(H_(2)O_(2)):m(COD_(Cr))比值下降至2.4:1,COD_(Cr)去除率仍高达93%,具有优异的处理效果。

活性炭电极的改性及对Co^(2+),Mn^(2+)和Ni^(2+)的电吸附性能

以商用活性炭(AC)为原料,分别采用磷酸和氢氧化钠改性的方法制备了两种不同的改性活性炭电极材料.采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、Brunauer-Emmett-Teller(BET)测试、傅里叶变换红外光谱(FTIR)和X射线光电子能谱(XPS)等手段以及电化学分析方法,对改性前后活性炭材料的表面性质和电化学性能进行了探究.结果表明,H_(3)PO_(4)改性使活性炭的孔隙分布更加密集,NaOH改性使活性炭表面的孔隙结构更加清晰均匀;H_(3)PO_(4)和NaOH改性均使活性炭的比表面积增加.循环伏安测试结果表明,改性前后活性炭电极在低扫描速率下均具备良好的双电层特性,并且两种改性处理均能提高活性炭电极的比电容;当扫描速率为5 mV/s时,未改性、H_(3)PO_(4)以及NaOH改性活性炭电极的比电容分别为36.51,77.25和85.19 F/g.电吸附实验结果证明,两种改性活性炭电极对Co^(2+),Mn^(2+)和Ni^(2+)均有较好的去除效果,电吸附过程均更加符合Langmuir模型,在初始浓度、电压和pH相同的条件下,NaOH改性电极对Co^(2+),Mn^(2+)和Ni^(2+)具有更高的去除率和吸附容量,去除率可分别达到96.84%,94.37%和96.90%,吸附容量分别为140.8,111.4和108.5 mg/g.

pH对δ-MnO_(2)吸附硫酸锰溶液中Co^(2+)、Ni^(2+)的影响

硫酸锰溶液中重金属离子的深度净化,一直是锰行业研究的热点和重点。利用X射线衍射(XRD)、扫描电镜(SEM)和红外光谱(FT-IR)等手段对所制备的δ-MnO_(2)进行表征,利用Visual Minteq软件模拟硫酸锰溶液中Mn、Co和Ni的离子形态随pH的变化关系,研究不同pH条件对δ-MnO_(2)吸附硫酸锰溶液中Co^(2+)、Ni^(2+)的影响。结果表明:δ-MnO_(2)结晶性较差,缺陷和空隙较多,表面羟基丰富。随着硫酸锰溶液pH升高,δ-MnO_(2)对于Co^(2+)和Ni^(2+)吸附率逐渐增加,Co^(2+)比Ni^(2+)更容易被吸附。在低pH下,δ-MnO_(2)吸附效果受结构缺陷和空隙影响,pH高于5时,在表面负电荷和羟基的共同作用下大量吸附Co^(2+)和Ni^(2+),Co^(2+)、Ni^(2+)吸附率最高达到99.98%、89.53%。对吸附后δ-MnO_(2)进行XRD和FT-IR分析进一步验证了吸附机理,为解决锰系电池原材料硫酸锰溶液中重金属杂质离子难去除问题提供一定基础。

氮掺杂荧光碳点用于Co^(2+)的超灵敏检测及细胞成像

首次以金银花和乙二胺为原料,通过水热法合成出性能优异的氮掺杂碳点(N-CDs)。制备的N-CDs具有丰富的官能团、良好的水溶性、低细胞毒性、高的荧光稳定性和良好的生物相容性。在最佳条件下,N-CDs能够高选择性地检出Co2+,N-CDs的荧光强度在0.5~3.6 nmol·L^(-1)范围内被Co^(2+)线性猝灭,检出限低至1.38 nmol·L^(-1),其猝灭机制属于内滤效应和静态猝灭。该方法也已成功应用于实际样品的精确分析。此外,N-CDs还可用于细胞成像及细胞内Co^(2+)传感。

Preparation and photocatalytic activity of Cu^(2+)-doped TiO_2/SiO_2

Cu^2＋-doped nanostructured TiO2-coated SiO2 （TiO2/SiO2） particles were prepared by the layer-by-layer assembly technique and their photocatalytic property was studied. TiO2 colloids were synthesized by the sol-gel method using TiOSO4 as a precursor. The experimental results showed that TiO2 nanopowders on the surface of SiO2 particles were well distributed and compact. The amount of TiO2 increased with the increase in coating layers. The shell structure appeared to be composed of anatase titania nanocrystals at 550℃. The 2-layer coated TiO2 particles on the surface showed a higher degradation rate compared with all the different-layer samples. The photocatalytic activity of Cu^2＋-doped TiO2/SiO2 was higher than that ofundoped TiO2/SiO2. The optimum dopant content was about 0.10wt%.

Three-photon-excited fluorescence of Tb^(3+)-doped CaO-Al_2O_3-SiO_2 glass by femtosecond laser irradiation

A near infrared to visible blue, green, and red upconversion luminescence in a Tb^3＋-doped CaO-Al2O3-SiO2 glass was studied, which was excited using 800 nm femtosecond laser irradiation. The upconversion luminescence was attributed to ^5D3→^7F5, ^5D3→^7F4, ^5D3→^7F3, ^5D4→^7F6, ^5D4→^7F5, ^5D4→^7F4, and ^5D4→^7F3 transitions of Tb^3＋. The relationship between upconversion luminescence intensity and the pump power indicated that a three-photon simultaneous absorption process was dominant in this upconversion luminescence. The intense red, green, and blue upconversion luminescence of Tb^3＋-doped CaO-Al2O3-SiO2 glass may be potentially useful in developing three-dimensional display applications.

Mechanism and behaviors of Cr3+-doped TiO2

TiO2 powder and TiO2 thin film on the surface of glazed ceramic tile were prepared by sol-gel method.The influences of different doping Cr3+ concentration on the photocatalytic activity of TiO2 were discussed, UV-visible and X-ray diffraction analysis were used to test the performance of TiO2 powder and film. The results indicate that photocatalytic activity of doping Cr3+-TiO2 thin film is higher than that of powder, and the interaction between Cr3+-doped and substrate can greatly enhance the photocatalytic activity. The results of X-ray diffraction and photoabsorption show that the Cr3+ -doped energy level in TiO2 is 0. 62 eV high from the top of valence band, which belongs to the type of deep energy level doping. On the basis of the semiconductor energy level theory and Cr3+ dopant energy level, the semiconductor energy level model of Cr3+ in TiO2 powder and thin film were established, and the doping mechanisms of Cr3+-doped in TiO2 powder and thin film were analyzed.

一种枣核生物炭的表征及其对污水中Cu^(2+)和Co^(2+)的吸附研究

一种廉价、易得、环保、无毒、安全的吸附剂有利于净化污水中的重金属,减少重金属对环境的污染和对人类的危害。本文采用高温热解法制得枣核生物炭,并对其进行了结构表征和分析,然后运用单因素实验法从吸附剂投料量、重金属离子初始质量浓度、吸附时间、温度、pH值五个因素研究了枣核生物炭对污水中Cu^(2+)和Co^(2+)的吸附影响。研究结果表明:20 mg的枣核生物炭在Cu^(2+)初始质量浓度为30 mg/L,pH值为5.0,温度为25℃的条件下吸附60 min,最佳吸附率可达99.12%;60 mg的枣核生物炭在Co^(2+)初始质量浓度为25 mg/L,pH值为6.0,温度为25℃的条件下吸附120 min,最佳吸附率可达94.04%。枣核生物炭对污水中重金属离子Cu^(2+)和Co^(2+)的吸附效果较佳。

Interfacial Structure of Nanocrystalline SnO_2 and SiO_2-doped SnO_2

The study of nanocrystalline SnO2 (n-SnO2) and SiO2-doped SnO2 (n-Si-SnO2) samples pre-pared by the sol-gel process showed that SiO2 doping can effectively restrained the growth of nanocrystalline SnO2 grains, thus improving thermal stability of the materials.

Study on the Synthesis of La(3)-doped Nano-TiO_2 and Photocatalytic Degradation of Methyl Orange

In this paper,La（3）-doped Nano-TiO2（La（3）-TiO2） was synthesized via hydrothermal process.Structure and optical properties of the synthesized samples were characterized via XRD,FT-IR,DRS,etc.The results showed that the phase transformation of TiO2 from anatase to rutile was effectively prevented by La（3）-doping,which improved the thermal stability of anatase,and also suppressed particle aggregation and grain growth of TiO2.The formation of Ti-O-La bond promoted UV absorption intensity of TiO2,and provoked red shift of absorbed light.And the spectra response range of TiO2 was extended significantly to visible light by La（3）-doping,then photocatalytic performance was improved effectively.Compared with pure nano-TiO2,the performance of La（3）-TiO2 which photocatalyticly degraded methyl orange was increased significantly.

Zero-field splitting parameters and local structures for tetragonal Cr^(2+) centers in Cr^(2+)-doped ZnSe semiconductors

The inter-relation between zero-field splitting （ZFS） parameters and local lattice structures of the （CrSe4）6 clusters in ZnSe semiconductors has been established by using the complete diagonalization （of the energy matrix） method. On the basis of this, the local lattice distortions, the ZFS parameters D, a, F and the optical spectrum for Cr2＋ ions doped into ZnSe are theoretically investigated, and the contributions of the spin singlets have been taken into account. The calculated ZFS parameters are in good agreement with the experimental values. From our calculations, the tetragonal distortion parameters AR = 0.091A and Aθ = 4.28° of Cr2＋ in ZnSe are acquired, and the results suggest that there exists a tetragonal expansion distortion for the local lattice structure of （CrSe4）6- clusters in ZnSe crystals. The influence of the spin singlets on ZFS parameters is also discussed, indicating that the contributions to ZFS parameters a and F cannot be ignored.

Crystallization and Luminescence Properties of Sm3＋-Doped SrO-Al2O3-SiO2 Glass-Ceramics

The Sm^（3＋）-doped SrO-Al2O3-SiO2（SAS） glass-ceramics with excellent luminescence properties were prepared by batch melting and heat treatment. The crystallization behavior and luminescent properties of the glass-ceramics were investigated by DTA, XRD, SEM and luminescence spectroscopy. The results indicate that the crystal phase precipitated in this system is monocelsian（SrAl2Si2O） and with the increase of nucleation/crystallization temperature, the crystallite increases from 66 % to 79 %. The Sm（3＋）-doped SAS glass-ceramics emit green, orange and red lights centered at 565, 605, 650 and 715 nm under the excitation of 475 nm blue light which can be assigned to the 4 G5/2→6 Hj/2（j=5, 7, 9, 11） transitions ofSm^（3＋）, respectively. Besides, by increasing the crystallization temperature or the concentration ofSm^（3＋）, the emission lights of the samples located at 565, 605 and 650 nm are intensified significantly. The present results demonstrate that theSm^（3＋）-doped SAS glassceramics are promising luminescence materials for white LED devices by fine controlling and combining of these three green, orange and red lights in appropriate proportion.

疏水性离子液体为溶剂对Co^(2+)和Cd^(2+)废水的萃取性能

研究了疏水性离子液体[Bmim]PF6(1-丁基-3-甲基咪唑六氟磷酸盐)、[Hmim]PF6(1-己基-3-甲基咪唑六氟磷酸盐)和[Omim]PF6(1-辛基-3-甲基咪唑六氟磷酸盐)对Co2+和Cd2+的萃取性能.结果表明,未加入螯合剂时,离子液体对Co2+和Cd2+的萃取率都很低.螯合剂的加入大大提高了离子液体对重金属离子的萃取性能,Co2+和Cd2+的萃取率分别由原来的2.06%和1.82%提高到96.37%和93.68%.不同螯合剂对离子液体萃取Co2+和Cd2+有一定的影响.离子液体碳链长度的增加有利于Co2+和Cd2+的萃取.与传统有机溶剂相似,离子液体萃取重金属离子过程中具有很强的pH摆动效应,当pH<2时,Co2+和Cd2+的萃取率几乎为0,而当pH>6时,Co2+和Cd2+的萃取率均大于90%.运用萃取过程中的pH摆动效应对Cd2+进行反萃取,实现了离子液体的回用.

交联淀粉微球对Co^(2+)的吸附行为及机理研究

研究了交联淀粉微球(CSM)对Co2+的静态吸附行为,并根据吸附等温线研究了吸附热力学性质,利用红外光谱仪、X射线衍射仪对吸附产物进行了结构表征,探讨了吸附机理。结果表明:在研究的浓度范围内,CSM对Co2+吸附等温线同时符合Langmu ir等温方程和Freund lich等温方程,不同温度下,CSM吸附Co2+的吸附焓变ΔH、吸附自由能变ΔG、吸附熵变ΔS均为负值,表明吸附是一个自发的、放热的过程,降低温度有利于吸附;CSM通过物理吸附、配位吸附方式吸附Co2+,并导致CSM结晶结构被进一步破坏。

Zn^2＋、Co^2＋和Mn^2＋对人工湿地基质生物膜的影响

研究了金属离子Zn2+,Co2+和Mn2+对复合垂直流人工湿地基质生物膜脱氢酶活性和多糖含量的影响.结果表明,在生物膜混合液中添加Zn2+能在短时间内(6h)迅速提高生物膜的酶活性,增加多糖含量,浓度为2mg/L的Zn2+可以在较长时间(72h)内保持生物膜的酶活性并且促进多糖的积累.Co2+和Mn2+对生物膜脱氢酶活性及多糖含量的影响较为相似.当Co2+浓度<1mg/L、Mn2+浓度<2mg/L条件下,6h时,对脱氢酶活性呈现了不同程度的促进作用,但随着Co2+和Mn2+离子浓度的增加,对脱氢酶活性的影响则表现为抑制作用,并且随着时间的延长,抑制作用越来越明显.在所研究的浓度和时间范围内,Co2+和Mn2+对多糖含量没有明显影响.

Cu^(2+)、Zn^(2+)、Co^(2+)对雨生红球藻生长的影响

以单细胞雨生红球藻为试验材料,以MAV为培养基通过单因子试验和正交试验研究了Cu2+、Zn2+、Co2+3种微量元素离子对雨生红球藻生长的影响。单因子试验结果表明,Cu2+、Zn2+、Co2+最佳质量浓度分别为2.0×10-7、3.4×10-7、9.0×10-7mol/L。正交试验结果表明,Cu2+的最适质量浓度是2.0×10-8mol/L;Zn2+的最适质量浓度是3.4×10-7mol/L;Co2+的最适质量浓度是6.0×10-7mol/L.。在这3种重金属离子的正交试验中在所研究的浓度范围内Cu2+和Co2+存在着较显著交互作用。

Mg^(2+)、Co^(2+)、Mn^(2+)和Ca^(2+)对葡萄糖异构酶活性的影响

The glucose isomerase(GI) was a metal activating enzyme It was most activated by Co 2+ and Mg 2+ ,and Mg 2+ was the best activator,whether the glucose or the xylose was the substrate When the glucose was substrate,the dissociation constant of Mg 2+ GI,Co 2+ GI and Mn 2+ -GI was 115 μmol/L,40 μmol/L, and 15 μmol/L respectively. The maximum activity of Mg 2+ GI,Co 2- GI and Mn 2+ GI was 100%,85%,and 20% respectively. When the xylose was substrate,the order of dissociation constant and maximum activity of the metal enzymes was the same Ca 2+ was a competitive inhibitor versus Mg 2+ ( K i 7 4 μmol/L)or Co 2+ ( K i 99 μmol/L). Compared with Mg 2+ GI,the K m of Co 2+ GI was more,and the V M of Co 2+ GI less The process of activity recovery from apo GI to metal GI showed that it was slow and of two