钕掺杂二氧化铅复合阳极的电化学性能研究

Electrochemical Performances of Neodymium Doped Lead Dioxide Composite Anode

利用电沉积法制备了钕(Nd)掺杂钛(Ti)基二氧化铅(PbO_2)复合阳极,采用扫描电子显微镜(SEM)、X射线衍射(XRD)、电化学阻抗谱、线性扫描伏安法、循环伏安法等对所制备电极的表面形貌、物相组成及电化学性能进行了分析.结果表明,Nd掺杂使得PbO_2阳极表面颗粒变小、结构更加致密,增大了电极比表面积,改善了电极电化学性能.PbO_2和PbO_2-Nd阳极表层主要为β-PbO_2,Nd掺杂提高了β-PbO_2的结晶纯度,改变了表面相的相对丰度,促进了β(101)晶面形成.PbO_2-Nd阳极具有更小的电化学反应电阻,更高的析氧电位,更强的电子交换能力和更长的使用寿命.将所制备电极应用于处理苯酚模拟难降解有机废水,PbO_2-Nd阳极对苯酚具有更好的电催化氧化效果,降解3 h,苯酚去除率达85.7%,COD去除率达73.8%.循环使用6次,PbO_2-Nd阳极电催化活性无明显衰减,显示出更好的电催化耐久性.

Neodymium（Nd） doped titanium（Ti）-based lead dioxide（PbO2） composite anode was prepared by electrodeposition.The surface morphologies and crystal structures of the as-prepared anodes were characterized by scanning electron microscopy（SEM） and X-ray diffraction（XRD） technique, respectively. The electrochemical performances of PbO2-Nd anode were studied by electrochemical impedance spectroscopy, linear sweep voltammetry and cyclic voltammetry. Additionally, the electrocatalytic activity and durability of PbO2-Nd anode were investigated through the degradation of simulative refractory organic wastewater of phenol. The results showed that Nd doping made the PbO2 anode surface structure dense and uniform with smaller sized crystal particles, which increased the specific surface area and improved the electrochemical properties of the anode. The surface crystal structures of PbO2 and PbO2-Nd anodes were mainly composed of β-PbO2. Furtheremore, Nd doping improved the crystal purity ofβ-PbO2, changed the relative abundance of the surface phase and promoted the formation of β（101） crystal plane. Moreover, the PbO2-Nd anode exhibited smaller electrochemical reaction resistance, higher oxygen evolution potential, stronger electron exchange capacity and longer life time than PbO2 anode. Upon electrocatalytic degradation of phenol wastewater with the PbO2-Nd anode for3 h, the removal rate of phenol and COD reached 85.7% and 73.8%, respectively. The electrocatalytic activity of the PbO2-Nd anode had no significant attenuation after being used for 6 times. The PbO2-Nd anode possessed better electrocatalytic activity and durability than PbO2 anode.