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1.
伴随环境污染问题日益加剧,借助半导体材料实现光能的光电转化在催化及环境领域引起广泛关注。本文借助电化学方法快速高效地合成不同沉积时间纳米赤铁矿薄膜电极。X射线衍射(XRD)、Raman光谱测试表明其成分为赤铁矿物相;原子力显微镜(AFM)观测颗粒尺寸约52.1(±1.48)nm×50.5(±1.49)nm,表面高度起伏分布于70~100 nm,且分布特征符合正态分布规律。紫外可见漫反射吸收谱显示电极可显著吸收350~600 nm波长范围可见光,计算得禁带宽度约2.0~2.1 e V。光电化学实验光电流密度-时间曲线及电流-电压曲线表明电极有良好的可见光光电催化活性,且反应符合Langmuir-Hinshelwood多相反应动力学模型。进一步选取效果较显著的沉积时间10 min电极研究其光电催化降解苯酚活性,0.65 V vs.SCE(饱和甘汞电极)恒电势光照条件下6 h苯酚降解率达62%,拟合一级动力学反应模型可知,反应速率常数k为0.16 h-1(R2=0.996)。综上,本文研究结果显示电化学法简单高效合成的纳米赤铁矿具有良好半导体性能且能够可见光光电催化降解苯酚等有机污染物。  相似文献   

2.
掺铜TiO_2/膨润土光催化剂的制备及其光催化性能研究   总被引:1,自引:0,他引:1  
以天然钠基膨润土为载体,利用四氯化钛水解法制备了掺铜TiO2/膨润土复合光催化剂;比较了不同量Cu2+对TiO2/钠基膨润土的修饰作用及不同光照条件对光催化性能的影响.采用分光光度计、XRD、IR及TG-DTA等测试手段对试验结果进行表征.结果表明,铜的掺入对TiO2/膨润土光催化活性有显著提高:当掺铜量为原土阳离子交换量的10.9%时,紫外光下催化效果最好;16.4%时太阳光下催化效果最好.复合后样品热处理温度为500 ℃,获得较理想的光催化活性.  相似文献   

3.
为使T iO2光催化剂能有效地利用可见光,采用前驱物薄膜分解法制备了掺杂锑的二氧化钛光降解触媒丝。玻璃纤维丝具有导光性,尤其适用于水体中污染物的光催化降解。初步研究制备条件、掺杂物浓度等对T iO2触媒丝性能的影响及所制备的玻璃基T iO2触媒丝对甲胺磷的可见光催化降解情况。所制掺杂T iO2光降解触媒丝在可见光下对甲胺磷具有良好的光催化降解性能,掺杂0.2%的触媒丝的光催化活性最好,6 h后对浓度为1.0×1-0 4m o l/L甲胺磷溶液的降解率达到了97.2%。  相似文献   

4.
天然水中铋的催化动力学光度法测定   总被引:2,自引:0,他引:2  
吕明  闫永胜 《地质实验室》1995,11(4):225-228
提出了通过铋(Ⅲ)催化H2O2氧化苯酚红褪色反应体系的新催化光度法,本法灵敏度高,选择性好,除Mn^2+,Mo^3+等离子外其余共存离子基本无干扰。实测了天然水中痕量铋,结果满意。  相似文献   

5.
在自然界,磁铁矿结构中广泛存在类质同象置换。部分置换离子显著改变磁铁矿的表面反应性,影响其对有机污染物的催化降解性能。本研究用熔融法合成一系列不同掺杂量的铬掺杂磁铁矿,利用X射线衍射(XRD)和X射线吸收精细结构谱(XAFS)等谱学技术对合成磁铁矿进行结构表征,并在中性条件下,探讨磁铁矿催化UV-Fenton反应降解酸性橙Ⅱ的性能。铬掺杂磁铁矿为立方晶系反尖晶石结构,Cr以+3价占据在八面体位。铬掺杂显著提高磁铁矿对酸性橙Ⅱ的催化降解性能,降解过程以异相UV-Fenton反应为主,遵循准一级动力学方程。反应160 min后,铬掺杂磁铁矿对酸性橙Ⅱ的矿化率达40%。  相似文献   

6.
(1)电沉积法电沉积法常被用来进行涂层或制备独立的结构。Erb等人首先将此法用于制备大块纳米金属材料,实验表明用传统的或稍加改性的电镀池和电镀条件可以制得晶粒尺寸为11nm的纳米晶镍材料。形成电沉积电镀池所需基本组分是阳极、阴极、电解质和直流电源。获得纳米晶结构材料的主要工艺参数包括:电解质基本组分、晶核添加剂、压力释放器、晶粒生长诱导剂、pH值、沉积温度、电流密度及循环电流。(2)无定形固体晶化法非晶固体是热力学亚稳态,在相应的条件下可以转变为更稳定的形态。转变时,无定形相晶化为一个或多个亚稳…  相似文献   

7.
沈瑞平 《地质论评》1983,29(1):87-97
由于光谱分析方法具有多元素同时测定的优点,故在化探中得到了广泛的应用。但至今在国内外书刊中所介绍的这类分析方法尚未能满足当前区域化探工作的要求。为此,本文制订了一种加罩电极载体蒸馏和电弧浓缩相结合的光谱分析方法,可在同一根电极上分组连续测定银、砷、硼、钡、铍、铋、镉、铈、钻、铬、铜、铁、镓、锗、汞、铟、镧、  相似文献   

8.
在MnSO-4-H-2SO-4和MnCl-2-HCl电解液体系中分别制备出电解二氧化锰(EMD),并在该二电解液中制备出掺杂MnO-2样品,而后用X射线衍射确定其晶型为MnO-2-γ,用扫描电镜观察其表面形貌,用XPS研究掺钛EMD表层物种;用模拟电池在实验室中快速检测掺杂样品的电性能,进而探讨了不同电解液体系中制备所得MnO-2与其晶体结构及电气性能的关系.  相似文献   

9.
TiO2-蒙脱石光催化降解苯酚的实验研究   总被引:1,自引:0,他引:1  
本文采用TiCl4在HCl中水解制备二氧化钛柱撑蒙脱石(TiO2-PILM)纳米材料,通过X射线衍射和BET N2比表面积分析对其进行表征,并研究其对苯酚在紫外光下的催化降解曲线,考察了苯酚的初始浓度、TiO2-PILM投放量、苯酚溶液pH值对光催化降解效果的影响。结果表明,制备的结构稳定的TiO2-PILM具有2.26nm大晶面间距和285.7m^2/g大比表面积。TiO2-PILM对苯酚有一定的光催化降解性,其过程是先吸附后降解。随苯酚初始浓度、TiO2-PILM投入量和苯酚溶液pH值的升高,TiO2-PILM对苯酚降解速率增大。在苯酚初始浓度为5mg/L、投样量为1g/L、pH为10时,TiO2-PILM对苯酚有较好的降解效果。  相似文献   

10.
本文描述了一种基于1,2,4,6-四苯基吡啶四氯金酸盐离子对的涂层金属丝金离子选择电极,在金浓度为10~(-2)-3×10~(-6)M范围内,电极具有良好的能斯特响应(斜率59mv/p Au)。试验了22种离子仅有铊严重干扰。用电极测定Ag-Pd-Au合金中的金,得到了满意的结果。对待测金属离子的带负电荷卤化物和假卤化物络合物为电活性物质的涂层金属丝离子选择电极已有报道,并已用于测定以卤络合物状态存在的铁、铜、汞、锌和铋,及以四硫代氰酸钴(Ⅱ)络合物状态存在的钴。将这些金属的络阴离子与Aliquat 33bs和benzalkonium形成的离子对络合物并入到PVC膜(聚氯乙烯)的涂层金属丝离子选择电极之中。四氯金酸(Ⅲ)与1,2,4,6-四苯基吡啶离子对的形成和萃取最近已有报道。这种离子对具有很高的萃取率和很好的选择性,可作为涂层电极的电活性物质,有关电极的选择性取决于离子对的萃取性能。本文报道了利用该电极选择测定金的方法。  相似文献   

11.
为进一步提高Ag-TiO2光催化效能,制备了还原氧化石墨烯(rGO)复合Ag-TiO2基的光电极。先通过对比不同的复合方式探究rGO对Ag-TiO2光催化剂表面电子传输和四环素降解效能的影响;再通过电化学阻抗谱测量、莫特-肖特基曲线等电化学手段对电极进行表征。结果表明:分层复合方式主要降低载体表面控制电极双层/薄膜的界面电阻,而全混复合方式主要降低总电荷转移电阻;分层电极的电子供体浓度随rGO质量分数增加而增大;在rGO质量分数为0.45%和0.25%时,分层复合和全混复合材料对四环素的降解速率分别比Ag-TiO2提高11.4%和2.3%;在外加0.5 V偏压下,分层复合电极LG6降解效率比未加外偏压时提高了5.3%,而全混复合电极MG2效率没有提升。分层复合方式能更有效地提高光催化剂表面电子传输效能。  相似文献   

12.
本方法建立了以多硫化合物、多碘化合物为缓冲剂(液体缓冲剂),上电极为光谱纯石墨电极、下电极为光谱纯石墨加罩电极的方式,采用控制试样法绘制工作曲线,电弧发射光谱法同时测定区域地球化学样品中As、Sb、Bi、Cd、Tl、In等6元素的测定方法。方法检出限为As1.0μg/g,Sb0.2μg/g,Bi0.1μg/g,Cd0.05μg/g,Tl0.1μg/g,In0.01μg/g;精密度(RSD,n=12)为As8.36%,Sb7.17%,Bi7.60%,Cd7.39%,Tl7.13%,In6.76%。方法用于测定国家一级标准物质GSD-1~GSD-12中As、Sb、Bi、Cd、Tl、In,测定值与标准值或参考值吻合。通过对1:50000区域地球化学调查样品中As、Sb、Bi、Cd、Tl、In实际分析,结果成图效果良好,具有简便快捷、成本低、检出限低、精度高等特点。  相似文献   

13.
青海冷龙岭地区位于北祁连成矿段的东段,是形成与海相火山岩有关的块状硫化物矿床及岩浆热液型矿床的有利地区,具有良好的找矿潜力。在1∶5万水系沉积物测量成果的基础上,对青海冷龙岭地区Au、Cu、Pb、Zn等17种元素的地球化学特征进行了初步分析,发现本区Ag、Pb、Zn、W、Sn、Bi、Mo、Ba、Cd等元素丰度明显高于青海省及祁连地区水系沉积物的平均丰度值;元素分布特征显示下奥陶统阴沟群除Hg、La、Ce相对贫化外,各元素都呈现不同程度的浓集,加里东期侵入岩中Ag、Cu、Pb、Zn、W、Au、Sn、Bi等元素富集程度较高,海西期正长岩内Ba、La、Ce等元素富集程度较为显著;R型聚类分析和因子分析显示区内的主要成矿元素组合为Cu Pb Ag Mo Ba La Ce,Au具有独立成矿的潜力。结合元素地球化学参数及富集离散特征,认为本区Au、Ag、Cu、Pb、Zn、Mo、La、Ce等元素具有一定的找矿潜力。本次工作共圈定8个综合异常。根据研究区成矿地质背景、异常特征及查证成果,与该区域内浪力克铜矿床和青分岭金矿床的地质地球化学特征对比研究后,优选出干沙河和三道路圈—倒阳河2个成矿远景区。  相似文献   

14.
在对相山铀矿田的深部勘查过程中陆续发现了一批铅、锌、银、铜多金属矿化,利用ICP-MS方法对多金属矿化中的重要金属矿物黄铁矿进行了微量元素分析。结果表明,黄铁矿中富集Co、Ni、Cu、Zn、Cd、Sb、Tl、Pb、Bi等微量元素。对比黄铁矿与矿区出露的主要岩浆岩和基底变质岩的LREE/HREE、(La/Yb)N、Y/Ho、Zr/Hf和Nb/Ta特征参数,结果表明多金属成矿流体在上升运移过程中受到变质基底的强烈混染。LREE富集,Hf/Sm、Nb/La和Th/La值小于1的特征表明多金属矿化成矿流体并非为富F流体,与铀成矿流体具有较大差异。微量元素Co含量与Co/Ni特征值显示矿化形成于中低温环境,成矿物质主要来自于基底变质岩。  相似文献   

15.
The distribution of selected critical elements in the sedimentary rocks of the Carboniferous coal-bearing series within the Polish Coal Basins is presented.Critical elements such as Be,Mg,Si,P,Sc,V,Co,Y,Nb,In,Sb,La,Ce,Hf,Ta,W,Bi were analysed using inductively-coupled plasma mass spectrometry(ICP/MS).Concentrations of elements such as Sb,Bi,In and,to a slightly lesser extent,Nb,as well as Sc,show average concentrations higher than those from the upper continental crust.The average concentrations of elements like Hf,Mg,P,Y,La,and Ce are slightly lower than in the upper continental crust.Other elements,such as Be,Co,Si,Ta,W and V have average concentrations that are similar,but slightly enriched or slightly depleted,relative to the upper continental crust.The research showed enrichment of some critical elements in the analysed samples,but not high enough that extraction would be economically viable.Statistical methods,which include correlation coefficients between elements and cluster analysis,reveal a strong positive correlation between elements like Be,Bi,Nb,Sc,Ta,W and V.Very high,almost total,positive correlation is also noted between La and Ce.  相似文献   

16.
To understand and/or avoid small-scale chemical heterogeneities within geological materials prepared as normal thin sections, in situ multiple trace element determination coupled with the simultaneous microscopic observation of the sample during analysis is preferable. We have examined fifty trace elements in thin (< 30 μm) layers of the NIST SRM 614 and 616 glass reference materials by LA-ICP-MS using different pit diameters and internal standard elements (Ca and Si). Compositional heterogeneities of Tl, Bi, As and Cd were found in NIST SRM 614 and 616 at the spatial resolution of ca. 10 0 μm. Except for these elements, the RSDs of six determinations for most elements were better than 10% in NIST SRM 614 when ablation diameters were < 50 μm. The measured concentrations for most elements in NIST SRM 614 and 616 agree with previous values in the literature at the 95% confidence level with the exception of W and Bi. New LA-ICP-MS data for K, As and Cd are also reported. The results support the view that the latest LA-ICP-MS is a powerful and flexible analytical technique for the determination of multiple ultra-trace element compositions in geological materials prepared as normal thin sections of the type that has been used for polarising optical microscopic observations since the end of the 19th century.  相似文献   

17.
张雷  王宁伟  景立平  方晨  董瑞 《岩土力学》2019,40(9):3493-3501
采用辽宁沿海地区淤泥质软土对铁、铜、铝和新型复合电极等不同电极材料进行室内电渗排水固结试验,从有效电势、电流、排水量与排水速率、能耗、电渗后土体含水率和承载力等对电渗效果进行分析。新型复合电极材料是由碳纤维、塑料排水板与铁片组成,其充分利用各种材料的优点,既解决了铁与碳纤维直接相连通电后易断的问题,又解决了电极腐蚀严重的问题。多组试验结果表明:新型复合电极材料的电渗排水固结使土体的加固强度提升较高,且相对均匀,加固强度达到160 kPa以上的土体面积占加固总面积的75%,说明新型复合电极材料的优越性。金属电极的腐蚀较为严重,且主要发生在阳极。根据电渗后阳极的腐蚀比,新型复合电极的腐蚀量明显低于金属电极,且新型复合电极可提高加固效果,节约电极材料成本。  相似文献   

18.
In this study, the treatability of marble processing wastewater by electrocoagulation using aluminum and iron electrodes was investigated. The sample used was from the marble-processing plant in Sivas and its turbidity, suspended solids, chemical oxygen demand and total solids concentrations were about 1,914?NTU, 2,904, 150 and 4,750?mg/L, respectively. The effects of various operating parameters such as initial pH, current density and electrolysis time on turbidity, suspended solids, chemical oxygen demand and total solids removal efficiencies were investigated. The settling characteristics of waste sludge produced and energy and electrode consumption were also determined. The optimum values of initial pH, current density and electrolysis time in electrocoagulation studies carried out using aluminum electrode were found to be 7.8, 30?A/m2 and 5?min, respectively. Under these conditions, the removal efficiencies obtained for turbidity, suspended solids, chemical oxygen demand and total solids were 98.5, 99.2, 55.2 and 92.4?%, respectively. Corresponding energy and electrode consumptions were 0.143?kWh/kg SS and 0.010?kg Al/kg SS. For iron electrode, the optimum parameter values were found to be 7.8 pH, 20?A/m2 and 5?min, respectively. Under these conditions, removal efficiencies for turbidity, suspended solids, chemical oxygen demand and total solids were determined as 94.3, 99.1, 54.2, and 96.1?%, respectively. Energy and electrode consumptions were 0.0571?kWh/kg SS and 0.0206?kg Fe/kg SS, respectively. Settling characteristics of sludge produced during experiments carried out using both aluminum and iron electrodes were fairly good. The results showed that electrocoagulation method can be used efficiently for the treatment of marble processing wastewater under proper operating conditions.  相似文献   

19.
毛韦达  胡翔 《地学前缘》2019,26(3):255-262
研究了La0.5 Sr0.5 Co0.8 Mn0.2 O3-δ钙钛矿活化过氧单硫酸盐对四溴双酚A(TBBPA)的降解作用,重点探讨不同的煅烧温度制备镧锶钴锰钙钛矿(LSCM82)的催化性能对过一硫酸盐降解TBBPA的影响,以及溶液的不同初始pH条件对优选材料体系降解效率的影响。结果发现,变价离子的氧化还原对Co3+/Co2+和(Mn4++Mn3+)/Mn2+是催化剂活性的主要贡献者。煅烧温度为950 ℃且具有适量间隙氧及比表面积的LSCM82-950催化反应速率较高。在中性pH环境条件下应用LSCM82-950活化过一硫酸盐降解水中TBBPA污染物,既可以使催化剂钴浸出很少,又能达到最大程度的TBBPA降解效果。  相似文献   

20.
Shallow vertical electrical sounding (VES) technique with Schlumberger electrode array (maximum distance between current electrodes was 50 m) through 25 VES points distributed on five traverses. Two 2D imaging lines with Wenner electrode array 30 m each corresponding to two VES traverses were conducted near well water contaminated with hydrocarbon materials at Karbala Governorate, Iraq. It is found that these techniques can give good results in delineating contaminated and clear zones but the 2D imaging technique was better in delineating the boundaries of the contaminated water plume and gave clear image of the subsurface distribution of the contaminated water vertically and horizontally.  相似文献   

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