负偏压下（Ni-Mo）/TiO2膜电极光电催化降解罗丹明B的性能和机理

用复合电沉积方法制备了(Ni-Mo)/TiO2薄膜电极,以扫描电子显微镜(SEM)、X射线衍射(XRD)、拉曼光谱(Raman Spectra)和紫外-可见漫反射光谱(DRS)对薄膜的表面形貌、晶相结构和光谱特性进行了表征,在负偏压和可见光作用下,以罗丹明B为模拟污染物研究了薄膜的光电催化性能.采用电化学技术和向溶液中加入活性物种捕获剂的方法对薄膜光电催化降解机理进行了探索.结果表明:(Ni-Mo)/TiO2薄膜是由粒径为50～100 nm的TiO2纳米粒子相和纳米晶Ni-Mo固溶体相构成的复合薄膜.薄膜具有较高的光电催化活性,在-0.4 V偏压和可见光照射下反应60 min,复合薄膜光电催化罗丹明B(c=5 mg/L)的降解率是多孔TiO2(P25)/ITO纳米薄膜的1.56倍.复合薄膜电极中Ni-Mo纳米晶合金对溶解氧和激发电子还原反应的催化作用是光电催化降解活性提高的重要原因.通过调节外加偏压,可以控制电极溶液界面间染料与活性氧化物种的存在形式及其相互作用,是研究可见光催化降解反应历程的有效方法.在负偏压和可见光作用下,羟基自由基和染料正离子自由基对染料的光电催化降解有决定性作用.     

负偏压下Ag@AgBr/Ni膜电极光电催化降解罗丹明B的性能和机理

用电化学方法制备Ag@Ag Br/Ni表面等离子体薄膜电极,以扫描电子显微镜(SEM)、X射线衍射(XRD)和紫外-可见漫反射光谱(UV-Vis DRS)对薄膜的表面形貌、晶相结构、光吸收特性进行了表征,在负偏压和可见光作用下,以罗丹明B为模拟污染物对薄膜的光催化活性和稳定性进行了测定,采用电化学技术和向溶液中加入活性物种捕获剂的方法对薄膜光电催化降解机理进行了探索。结果表明:最佳工艺下制备的Ag@Ag Br/Ni膜电极是由表面沉积纳米Ag的纳米晶Ag Br颗粒构成的薄膜,具有显著的表面等离子共振效应。薄膜具有优异的光电催化活性和良好的催化稳定性,在最佳负偏压和可见光照射下反应12 min,薄膜光电催化罗丹明B(c=5 mg·L~(-1))的降解率是多孔Ti O2(P25)/ITO纳米薄膜的10.2倍。相对于未加偏压的光催化,降解率提高了2.0倍;在保持薄膜光催化活性基本不变的前提下可循环使用5次。电极表面纳米Ag粒子的等离子体共振对于光阴极反应(导带反应)的活化作用是光电催化活性提高的重要原因。提出了负偏压下Ag@Ag Br/Ni表面等离子体薄膜光电催化降解罗丹明B的反应机理。     

光电催化降解磺基水杨酸的研究

 建立了以刮浆工艺制得的TiO2／Ni为工作电极、泡沫镍为对电极、饱和甘汞电极为参比电极的光电催化反应体系,研究了在磺基水杨酸（SSal）的光电催化降解过程中,外加电压和溶液pH值对降解速率的影响．实验发现,外加阳极偏压为700mV时,SSal能发生有效降解,降解速率受溶液pH值的影响;随着SSal降解的进行,阳极表面电阻出现较大的变化．另外还研究了SSal光电催化降解过程中的电流变化特征．     

辉光放电等离子体处理阳离子染料结晶紫废水

用辉光放电等离子体技术对结晶紫进行了降解脱色处理,考察了多种因素对结晶紫降解效果的影响。实验发现,提高电解质浓度和增加电压均可提高结晶紫的脱色效果,考虑到电极损耗,辉光放电最佳条件为:电解质浓度为2 g/L Na2SO4,电压为600 V。当改变溶液的初始pH值时,结晶紫的脱色率随溶液的初始pH值升高而增加,加入一定量H2O2能明显地提高结晶紫的脱色效率;若加入0.4 mmol/L Fe2 ,5 min时结晶紫的脱色率由原来的13.64%增加到91.36%。结果表明,辉光放电产生的.OH对结晶紫的降解起重要作用。最佳条件下,40 min内的脱色率达到93%,降解率为74%。     

三维电极电助光催化降解直接湖蓝水溶液的研究

 以500W高压汞灯为光源,在TiO2光催化剂和电催化剂同时存在下,联合多相三维电极技术与光催化技术,对直接湖蓝5B水溶液进行了电助光催化降解的研究．实验结果表明,浓度为0．5mmol／L的直接湖蓝5B水溶液经30min的光电催化降解,其大环结构可迅速破坏,颜色可迅速褪去,色度去除率高达96．8％,COD去除率可达66．7％．考察了空气流速、光催化剂加入量、底物的初始浓度、电解槽电压、pH值、电导率、以及曝气量等因素对直接湖蓝5B脱色率及COD去除率的影响．     

负偏压下Ag@AgBr/Ni膜电极光电催化降解罗丹明B的性能和机理

用电化学方法制备Ag@AgBr/Ni表面等离子体薄膜电极,以扫描电子显微镜（SEM）、X射线衍射（XRD）和紫外-可见漫反射光谱（UV-Vis DRS）对薄膜的表面形貌、晶相结构、光吸收特性进行了表征,在负偏压和可见光作用下,以罗丹明B为模拟污染物对薄膜的光催化活性和稳定性进行了测定,采用电化学技术和向溶液中加入活性物种捕获剂的方法对薄膜光电催化降解机理进行了探索。结果表明：最佳工艺下制备的Ag@AgBr/Ni膜电极是由表面沉积纳米Ag的纳米晶AgBr颗粒构成的薄膜,具有显著的表面等离子共振效应。薄膜具有优异的光电催化活性和良好的催化稳定性,在最佳负偏压和可见光照射下反应12 min,薄膜光电催化罗丹明B（c=5 mg·L^-1）的降解率是多孔TiO₂（P25）/ITO纳米薄膜的10.2倍。相对于未加偏压的光催化,降解率提高了2.0倍;在保持薄膜光催化活性基本不变的前提下可循环使用5次。电极表面纳米Ag粒子的等离子体共振对于光阴极反应（价带反应）的活化作用是光电催化活性提高的重要原因。提出了负偏压下Ag@AgBr/Ni表面等离子体薄膜光电催化降解罗丹明B的反应机理。     

钛基二氧化铅电催化电极的制备及电催化性能研究

以电沉积法制备了钛基PbO2电极，优化并确定了电极的制备工艺，以苯酚为目标有机物，考察了电极的电催化氧化性能，研究结果表明，该电极的电催化性能优于传统的DSA钛基RuO2电极。采用该电极，在10Ma/cm^2电流密度下通过0.72Ah电量后，可使100Ml、COD浓度为270mg/L的苯酚溶液中的苯酚完全分解，COD去除率为67.4%，单位电量COD降解量为0.254mgCOD/Ah，且电流效率随电流密度的增加而减小，初步研究了苯酚的电催化氧化机理，提出了苯酚的电催化氧化可能是由苯酚的直接电化学氧化为苯醌及苯醌的间接电化学氧化有机酸两部分组成。     

二茂铁衍生物L-B膜在CdSe/Fe(CN)_6~((3-)/(4-))界面的中介催化作用

测定了CdSe薄膜电极及硬脂酸二茂铁酯L—B膜修饰后在Fe(CN)_6~(3-/4-)溶液中于白光和650nm单色光下的阻抗行为。用计算机非线性曲线拟合求出了等效电路中的元件参数值。进一步计算了CaSe薄膜电极光氧化还原反应速度常数。结果表明,修饰在CdSe薄膜电极上的硬脂酸二茂铁酯L—B膜在光诱发的CdSe/Fe(CN)_6~(3-/4-)界面电荷转移中加速电荷的传递起中介催化作用。     

光电催化降解邻苯二甲酸二乙酯的研究

采用sol-gel法制备TiO2薄膜光电极，以该电极为工作电极，铂丝作对电极，饱和甘汞电极为参比电极，对邻苯二甲酸乙酯的光电催化降解进行了研究。结果表明：该电极具有n型半导体的特征行为，在外加偏压为＋0．7v、pH=2、50mg／L的H2O2中对初始浓度为50mg／L的DEP溶液光照180min降解率达67．85％，讨论了氧的存在、外加偏压等因素对光电催化反应的影响。     

石墨烯修饰Y型TiO_2纳米管光电极制备及其对氨氮催化氧化性能

采用三步阳极氧化法和一步循环伏安电沉积法制备了还原氧化石墨烯(rGO)修饰的Y型TiO_2纳米管(rGO/Y-TiO_2NTs)电极。通过场发射电子扫描显微镜(FESEM)、X射线能谱(EDS)、X射线衍射(XRD)、紫外可见漫反射光谱(UV-Vis DRS)及拉曼光谱(Raman)等对电极样品进行了表征。以rGO/Y-TiO_2NTs电极为光阳极,测试了不同循环伏安沉积圈数对电极光电流响应的影响,考察了在1.0 V偏压下电极对氨氮的光电催化氧化性能。结果表明,高度有序的Y-TiO_2NTs为锐钛矿型,具有大的比表面积,表面修饰平滑透明rGO薄膜后可显著提高其光电催化效率,沉积圈数为30时电极在30 min内对氨氮的光电催化氧化效率为95.9%。     

Influence of highly efficient PbS counter electrode on photovoltaic performance of CdSe quantum dots-sensitized solar cells

PbS electrode with high catalytic activity to S_n ^2? reduction certificated by the measurements of electrochemical impedance spectroscopy and cyclic voltammetry was prepared by a simple method. The high catalytic activity makes it be a low-cost alternative counter electrode to platinum (Pt) to be used in quantum dots-sensitized solar cells (QDSSCs) based on polysulfide electrolyte. The photovoltaic performance enhancement of the quantum dots (QDs)-sensitized semiconductor thin films due to the PbS counter electrode was evaluated by fabricating QDSSCs based on CdSe QDs-sensitized ZnO (SnO₂) thin film. CdSe QDs-sensitized ZnO thin film has the lower internal total series resistance and electron transmission time, the higher electron lifetime and electron collection efficiency than the CdSe QDs-sensitized SnO₂ thin film. Replacing the Pt counter electrode with the PbS counter electrode leads to more improvement on the short circuit photocurrent density for QDSSC based on the ZnO thin film than the SnO₂ thin film. Therefore, the process to limit the photovoltaic performance of CdSe QDs-sensitized solar cell and the possible way to improve the photovoltaic performance were analyzed.     

NanoTiO2-聚苯胺复合膜电极电化学降解2,4,6-三硝基苯酚

利用溶胶-凝胶法和电化学聚合制得Ti/nanoTiO2-聚苯胺(PAn)复合膜电极,用X射线衍射仪、扫描电子显微镜及循环伏安法对电极的结构、表面形貌和电催化性能进行了表征。SEM测试表明,Ti/nanoTiO2-PAn电极上聚合的苯胺呈短纤维形貌,短纤维的直径较为均匀,为150 nm左右。以此电极进行电化学降解2,4,6-三硝基苯酚,在25℃,电解时间为180 min,电极间距离为2 cm,废水pH值在7～8之间,浓度为50 mg/L的2,4,6-三硝基苯酚模拟废水中COD,降解效率可达到41.2%。     

Electrochemical Degradation of o-Chloronitrobenzene by Three-dimensional Electrodes

Degradation of o-chloronitrobenzene wastewater was experimentally investigated at a three-dimensional electrode(TDE) with granular activated carbon as the particle electrode, graphite as the anode, and stainless steel plate as the cathode. The kinetic model of o-chloronitrobenzene degradation was studied, and the effects of pH, electrolysis time, particle electrode, electrolyte concentration, and initial concentration of the solution on degradation efficiency were investigated to determine the optimal operating conditions. The degradation of o-chloronitrobenzene by oxidation at the TDE was monitored by chemical oxygen demand(COD) measurements, UV-Vis absorption, and high performance liquid chromatography(HPLC). COD degradation by electrochemical degradation followed pseudo-first order kinetics with respect to the concentration of o-chloronitrobenzene solutions. Optimal reaction conditions included 15 g of activated carbon as the particle electrode, 400 mg/L o-chloronitrobenzene solution containing 0.10 mol/L Na₂SO₄, pH=3, and 60 min of electrolysis. The UV-Vis absorption spectra and HPLC results illustrate that the benzene ring in o-chloronitrobenzene was rapidly broken down to form aliphatic substances through electrochemical degradation. COD degradation was approximately 98.5% at optimal conditions.     

镍氢氧化物修饰玻碳电极的制备及其电化学行为

采用一种新方法———镀膜/循环伏安法成功制备了镍氢氧化物修饰玻碳电极。考察了影响镍氢氧化物膜电催化活性的因素,确定最佳富集时间为2min,最佳富集电位为-1.4V。讨论了成膜过程及机理。膜氧化峰电流及催化氧化峰电流均受扩散控制。制得的镍氢氧化物膜修饰电极具有相当的稳定性,并对H2O2的电氧化表现出较高的电催化活性。该电极对H2O2响应的线性范围为1.71×10-5~1.33×10-2mol/L,检出限为2.86×10-6mol/L(S/N=3)。     

聚3-氯噻吩修饰CdSe纳米棒复合膜电极光电化学性能研究

采用水热法制备了具有闪锌矿和纤维锌矿结构的CdSe纳米棒. 纳米棒直径约为100 nm, 长度约为300 nm. 当外加电极电势为-0.6 V 时, 经聚3-氯噻吩[Poly(3-chlorothiophene), P3CT]修饰的CdSe纳米棒具有最大光电流, 并且CdSe/P3CT复合膜电极最高光电转换效率(IPCE)为13.5%, 低于CdSe纳米棒膜电极17.7%的最高IPCE. CdSe/P3CT复合膜电极中存在p-n异质结, p-n异质结的存在使得CdSe/P3CT复合膜电极在长波区(>410 nm)的IPCE整体高于CdSe纳米棒薄膜电极的IPCE.     

Preparation and Characterization of Mixed‐Valent Nickel Oxide/Nickel Hexacyanoferrate Hybrid Films and Their Electrocatalytic Properties

Polynuclear mixed‐valent nickel oxide and nickel hexacyanoferrate hybrid film was prepared on glassy carbon electrode by multiple scan cyclic voltammetry. The film growth was monitored using electrochemical quartz crystal microbalance (EQCM). The cyclic voltammogram of the nickel hexacyanoferrate film is characterized by single redox couple whereas nickel oxide/nickel hexacyanoferrate hybrid film exhibits two redox couples. Cyclic voltammetric features suggest that the charge transfer process in both films resembles that of surface‐confined redox species. In stronger basic solution (pH ≥9), nickel hexacyanoferrate film was gradually converted into nickel oxide film during potentiodynamic cycling. The peak potential of nickel oxide redox couple moved into more negative side with increasing pH of contacting solution whereas the peak potential of nickel hexacyanoferrate redox couple remains the same. Electrocatalytic behavior of hybrid film coated electrodes toward ascorbic acid, hydrazine and hydroxylamine was investigated using cyclic voltammetry technique. Analytical application of nickel oxide/nickel hexacyanoferrate hybrid film electrode was tested in amperometry and flow injection analysis.     

电化学沉积CdSe纳晶薄膜的性能及沉积机理

电化学沉积是半导体薄膜制备的一种简便方法,常用于Ⅱ-族化合物半导体薄膜的制备.通过电沉积条件的适当改变可成功地在导电衬底上制备半导体纳晶薄膜^[1].CdSe薄膜作为一种透光性好、导电性好的半导体材料,可进行光学性能和光电性能方面的研究,而半导体纳晶多孔电极的光电化学特性与体材料之间有很大不同.本文采用电化学沉积法制备了CdSe纳晶薄膜并研究了其性能,通过扫描隧道显微镜(STM)形貌分形分析进一步研究其沉积机理.     

采用新颖喷墨打印技术制备的薄膜LiCoO2电极及其电化学性能

采用喷墨打印技术制备了LiCoO2薄膜电极. 用X射线衍射、扫描电镜(SEM)、循环伏安和恒电流充放电试验对薄膜电极进行结构表征和电化学性能测试. SEM结果表明, 所制备的薄膜电极表面粒子分布均匀, 厚度约为1.27 μm. 经过轻微热处理(450 ℃, 30 min)的薄膜LiCoO2电极呈现出稳定的充放电循环性能. 当以20 μA/cm2进行充放电时, 第50次循环容量保持率约为首次放电容量(81 mA·h/g)的87%, 10次循环后的充放电过程的充放电效率均接近100％.     

Self-assembly and optical properties of water-soluble porphyrin alternating CdSe nanoparticulate films

A new type of self-assembled film was prepared by alternating deposition of oppositely charged meso-tetra-(4-trimethylaminophenyl) porphyrin nickel iodide (NiTAPPI) and citrate-stabilized CdSe nanoparticles. The stepwise deposition process was monitored by means of UV–vis spectroscopy. The interaction between the porphyrin and CdSe nanoparticles was characterized with UV–vis and fluorescence spectra. The SEM images showed the formation of densely packed two-dimensional array and the conversion of disorder-to-order of CdSe nanoparticles on the quartz substrate modified by PDDA when depositing positively charged NiTAPPI. The self-assembled film placed in ambient air exhibited significant enhancement of fluorescence intensity. The effects of heat treatment and UV-light irradiating on fluorescence properties of the composite films were investigated in details.