不同金属氧化物阳极上甲基橙的电化学氧化降解

分别以Ti/SnO2+Sb2O3和Ti/SnO2+Sb2O3/PbO2电极为阳极进行甲基橙的电化学氧化,研究了两种金属氧化物阳极上甲基橙氧化降解过程的反应速率、电流效率及COD的变化.结果表明,两种金属氧化物阳极都能有效氧化降解甲基橙,氧化反应符合一级反应动力学规律,在Ti/SnO2+Sb2O3和Ti/SnO2+Sb2O3/PbO2电极上甲基橙氧化降解过程的表观速率常数分别为0.148和2.43×10-2 min-1. 以Ti/SnO2+Sb2O3为阳极电解30 min,甲基橙的浓度从初始时的0.305 mmol/L降至4.89×10-3 mmol/L,甲基橙的转化率达98.4%;在Ti/SnO2+Sb2O3/PbO2电极上,相同电解时间下甲基橙的浓度只降至0.14 mmol/L,转化率为55.0%. 对不同电极上甲基橙电化学氧化过程电流效率的研究表明,Ti/SnO2+Sb2O3电极的电流效率明显高于Ti/SnO2+Sb2O3/PbO2电极. Ti/SnO2+Sb2O3电极的反应速率大、电流效率高主要源于其较高的析氧电位.     

Ti/SnO2+Sb2O3/PbO2电极在硫酸溶液中Cr3+氧化的电化学性能

对用聚合前驱体溶液通过热分解法制备的Ti/SnO2+Sb2O3/PbO2电极在硫酸溶液中Cr3+电化学氧化的电化学性能进行了研究. 分别测定了以Ti/SnO2+Sb2O3/PbO2和PbO2为阳极，硫酸介质中Cr3+电化学氧化过程的极化曲线、抗腐蚀性以及不同操作电流密度、Cr3+浓度、反应温度、硫酸浓度下的电流效率. 实验结果表明，聚合前驱体溶液通过热分解法制备的Ti/SnO2+Sb2O3/PbO2电极与PbO2电极相比具有更高的电催化活性和抗腐蚀性.     

4种DSA阳极的制备及其电催化性能比较

制备了Ti/SnO2+Sb2O3, Ti/PbO2, Ti/Fe-PbO2和Ti/SnO2+Sb2O3/Fe-PbO2四种形稳阳极材料,对其表面形貌进行了表征,同时测试了其在H2SO4溶液中的极化曲线. 以苯酚为目标污染物,用其进行了电催化降解实验. 结果表明,Ti/SnO2+Sb2O3/Fe-PbO2电极催化活性最好,苯酚降解率可达95%. 添加锡锑中间层后,Ti/SnO2+Sb2O3/Fe-PbO2电极寿命显著提高,可达16 h. 苯酚在4种阳极上的电催化降解反应遵循一级反应动力学规律.     

新型钛基PbO2阳极电氧化降解 有机污染物的特性研究

用电沉积法制备了PbO2/SnO2+Sb2O3/Ti、Bi-PbO2/SnO2+Sb2O3/Ti、PbO2（超声）/SnO2+Sb2O3/Ti、Bi-PbO2（超声）/SnO2+Sb2O3/Ti等4种二氧化铅电极,用稳态极化曲线表征了它们的电催化性和选择性,分析了电解苯酚废水的处理效果,用加速寿命实验测定了电极寿命,用电子扫描电镜表征了沉积层晶相和形貌。结果表明：掺Bi可以提高电极的电催化性和电氧化苯酚的选择性,超声电沉积可以增大电极比表面积,提高电极的表观催化活性,显著增长电极加速寿命。     

电解条件对Cr3+电化学氧化过程瞬时电流效率的影响研究

在隔膜式电解槽中,分别以PbO2和Ti/SnO2+Sb2O3/PbO2为阳极,以Cu为阴极,对硫酸介质中影响Cr3+电化学氧化生成Cr2O72-过程瞬时电流效率的因素进行了研究.实验结果表明,在硫酸介质中进行Cr3+电化学氧化时,操作电流密度、反应温度、硫酸浓度、阳极材料、超声等因素都会影响Cr3+电化学氧化生成Cr2O72-过程的瞬时电流效率.瞬时电流效率随操作电流密度和硫酸浓度的增大而下降,随反应温度的升高而增大;Ti/SnO2+Sb2O3/PbO2电极与PbO2电极比有较大的比表面积,瞬时电流效率高于PbO2电极;电解体系中引入超声,减小了电极表面的扩散层厚度,强化了Cr3+向电极表面的传质, 超声场作用提高了瞬时电流效率. 在25℃、硫酸浓度为1.5mol·L-1、 Cr3+浓度为0.070 mol·L-1、操作电流密度为0.02～0.15A·cm-2时,Ti/SnO2+Sb2O3/PbO2为阳极的瞬时电流效率比PbO2电极提高了4%～12%;在Cr3+浓度为0.040mol·L-1下操作,以Ti/SnO2+Sb2O3/PbO2为阳极,有超声场作用的瞬时电流效率比无超声作用时的瞬时电流效率提高了4%～11%.     

钛基二氧化铅电极电催化降解2-氯苯酚

用热解法和电沉积法分别制备了Ti/β-PbO2、Ti/SnO2+Sb2O3/β-PbO2和Ti/α-PbO2/β-PbO2 3种电极,并采用电子扫描电镜、X-射线衍射仪和阳极极化曲线分别对所制备的电极进行了表征,并以2-氯苯酚为目标污染物,考察了3种电极的电催化氧化性能和电极使用寿命.结果表明,中间层对表面活性层的结构形貌和催化活性都有很大影响,其中Ti/α-PbO2/β-PbO2电极析氧电位最高,对2-氯苯酚的去除率可达99.3%,且具有较长的电极使用寿命和较低的槽电压;3种电极对2-氯苯酚降解反应均遵循1级反应动力学规律.     

探讨不同阳极材料对电催化氧化含酚废水效果的影响

采用高温热分解技术制备Ti/SnO2-Sb2O3、Ti/SnO2-Sb2O3/PbO2和Ti/PbO2电极。通过对三种电极的催化性能进行比较,结果显示Ti/SnO2-Sb2O3电极较其他两种电极具有更好的催化活性和稳定性。以Ti/SnO2-Sb2O3为阳极,钛板为阴极,利用正交实验得出电催化氧化的最优参数为:电压5V、NaCl浓度0.1mol·L-1、pH值7。     

Ti/IrO2-Ta2O5阳极电催化氧化法处理含酚废水

采用新型的钛基金属氧化物涂层电极(Ti/IrO2–Ta2O5)作为阳极,石墨作为阴极对含酚模拟废水进行电催化氧化降解实验。当电解条件为电压U=9.0V;电流I=2.5A;板间距d=3.0cm;电解质NaCl浓度20.0g·L-1,初始pH=7.0时,初始浓度为1000mg·L-1苯酚模拟废水电解90min后,处理效果较理想,其中电流和电解质浓度为主要影响因子。Ti/IrO2–Ta2O5阳极电催化氧化降解苯酚的过程符合一级反应动力学。     

间接电氧化媒质Ce4+/Ce3+的循环与再利用

设计了一种适用于间接电氧化合成反应,中试规模的填充式隔膜电解槽.该电解槽以铜板为阴极,PbO2/Ti石墨颗粒填充电极为阳极,电解液[0.16mol/L Ce2(SO4)3,1.5 mol/L H2SO4]采用外循环的方式控制其温度为30～50℃,在50A/m2的电流密度下电解,获得大于80%的电流效率.讨论了电极材料、电流密度、电解液温度、Ce3+浓度和循环次数等对电流效率的影响.其中Ce3+浓度是限制电流密度和影响电流效率的主要因素;电解液在间接电氧化对甲氧基甲苯反应中连续循环使用20次,仍然保持高于85%的电流效率;PbO2/Ti石墨颗粒填充电极使用寿命超过6个月.     

Ti/SnO_2+Sb_2O_4+CF/PbO_2电极在酸性溶液中反应历程的拟定及推导

拟定并推导了Ti/SnO2+Sb2O4+CF/PbO2电极在酸性溶液中的反应历程,确定了速度控制步骤和动力学表达式。     

Ti/SnO_2+Sb_2O_3+MnO_2/PbO_2阳极的制备及其性能

用热分解和电沉积联合方法制备了Ｔｉ／ＳｎＯ２＋Ｓｂ２Ｏ３＋ＭｎＯ２／ＰｂＯ２阳极．对该类电极进行了ＥＤＳ、ＳＥＭ、ＸＲＤ研究．测定了电极在１ｍｏｌ／ＬＨ２ＳＯ４溶液中的使用寿命和动力学参数．考察了其作为阳极用于含酚废水处理时的性能．结果表明，所制备电极在硫酸溶液中具有优良的电催化活性和电化学稳定性．     

Interactive Oxidation of Photocatalysis and Electrocatalysis for Degradation of Phenol in a Photoreactor

TiO2/C particles as photocatalyst were prepared by dipping TiO2 suspension solution with activated carbon and were applied in the photocatalytic-electrocatalytic degradation of phenol, the Ti/SnO2+Sb2O3/PbO2 electrode and oxygen diffusion electrode were used as anode and cathode respectively, and a 250 W ultraviolet lamp (365 nm) as side light source. The SEM results of TiO2/C and Ti/SnO2+Sb2O3/PbO2 anode indicated that the TiO2 on carbon particles was uniform and PbO2 film on the surface of anode was in cauliflower form, the XRD result of oxygen diffusion electrode showed that only crystalline graphite was found. The influential parameters of degradation process such as applied cell voltage (E), initial concentration of phenol (C0), amount of TiO2 catalyst and air flow rate (v) were discussed. Under the following experimental conditions of C0=50 mg/L, pH=6, E=2 V, TiO2 0.98 mg/mL, v=382.2 mL/min, and light intensity I=10.5 mW/cm2, phenol could be entirely degraded, and about 89% of total organic carbon (TOC) was removed after 3 h degradation.     

Effects of Precursors for Preparing Intermediate Layer on the Performance of Ti/SnO2+Sb2O3/PbO2 Anode

The Ti/SnO2+Sb2O3/PbO2 anode with SnO2+Sb2O3 intermediate layer obtained by the polymeric precursor method (PPM) and with the conventional route was studied. The morphology and microstructure of SnO2+Sb2O3 intermediate layer derived from different precursors and the top PbO2 active layer were examined by means of ESEM and XRD. The lifetime and electrocatalytic activity of the anode were also assessed by the cyclic voltammetry and accelerated lifetime test in 1.0 mol/L H2SO4 solution. It was found that precursor solvents affected lifetime, microstructure and morphology of the anode, and had little influence on electrocatalysis activity of the electrodes. The accelerated lifetime of Ti/SnO2+Sb2O3/PbO2 anode with intermediate layer prepared by PPM was 29.5 h in 1.0 mol/L H2SO4 solution, which was respectively about four times and twice that of the anode prepared with ethylene glycol and ethanol. After the anode was subjected to thermal corrosion, the lifetime still reached 27 h in contrast to the others.     

钛基IrO2+SnO2电极的析氧性能及其在电合成丁二酸中的应用

通过热分解法制备了IrO2+ SnO2/Sb2 O3+ SnO2/Ti、IrO2+ SnO2/Ti、IrO2+ Ta2O5/Sb2O3+ SnO2/Ti电极,通过线性伏安、电化学阻抗、强化寿命测试等研究了钛基涂层电极在1 mol· L-1硫酸溶液中的析氧性能.采用EDX、SEM等考察了电极的表面元素分布和电极强化寿命测...     

Electrochemical degradation of phenol in aqueous solution on bismuth doped lead dioxide: a comparison of the activities of various electrode formulations

This paper describes the development of electrochemical processes for the oxidative degradation of toxic organic chemicals in waste waters. Doped bismuth lead dioxide anodes have been tested by the kinetic study of phenol anodic oxidation in aqueous solution. The main products during oxidative degradation of phenol are 1,4- benzoquinone, maleic acid and carbon dioxide. Several deposits of Bi2O5–PbO2 on Ti/(IrO2–Ta2O5) substrates have been prepared by anodic oxidation of Pb2+ and Bi3+ in aqueous solutions containing perchloric acid to increase the solubility of bismuth. To study the effect of perchlorate ions, the efficiency of the PbO2 deposit prepared from lead nitrate in an aqueous solution (pure PbO2) was compared with that of a deposit prepared from perchloric acid solution (perchlorate doped PbO2). Although the phenol is oxidized at the same rate on the two deposits, the charge corresponding to the total elimination of 1,4-benzoquinone is three times higher for perchlorate doped PbO2 than for pure PbO2. Phenol degradation is more efficiently carried out on a PbO2 anode doped with perchlorate and with bismuth than on the same electrode doped only with perchlorate. Among the electrodes tested in this work, the pure PbO2 anode is the most efficient for phenol degradation. It is assumed that certain active sites on the anode occupied by perchlorate ions do not participate in the transfer of oxygen atoms and that for the PbO2 electrode doped with bismuth, oxygen evolution is favoured to the detriment of oxygen atom transfer.     

Service life of Ti/SnO2–Sb2O5 anodes

The service life of SnO2–Sb2O5 coated anodes prepared by the spray pyrolysis technique using Ti or Ti/IrO2 substrate, was studied under galvanostatic conditions (100mAcm–2 in 1m H2SO4 at 25°C. The results showed that the presence of an IrO2 interlayer between the Ti substrate and the SnO2–Sb2O5 coating (Ti/IrO2/SnO2–Sb2O5 anode) strongly increases the service life of the anode. This beneficial action of the IrO2 interlayer was attributed to its high anodic stability and its isomorphous structure with TiO2 and SnO2. Cyclic voltammetry and steady-state polarization curves showed that the electrochemical behaviour of the Ti/IrO2/SnO2–Sb2O5 electrode lies between the behaviour of the Ti/IrO2 and the Ti/SnO2–Sb2O5 electrodes due to incorporation of IrO2 in the SnO2–Sb2O5 coating during its preparation.     

Metal modified (Ni,Ce, Ta) Ti/SnO2–Sb2O5–RuO2 electrodes for enhanced electrochemical degradation of Orange G

Journal of Applied Electrochemistry - Ni, Ce, and Ta modified Ti/SnO2–Sb2O5–RuO2 anodes were first prepared by thermal decomposition strategy and applied for Orange G degradation to...