【摘要】 用溶胶-凝胶法制备了稀土(Ce)掺杂TiO2电极,优化了制备改性TiO2电极的稀土掺杂量、热处理温度及热处理时间.借助于油田废水化学需氧量(COD)去除情况分析了电极的电催化氧化能力,并分析了电极结构与电催化特性之间的关系.采用SEM,EDX和XRD分析了制备电极的表面形貌、元素组成和晶体结构.结果表明,掺杂Ce后电极的表面凹凸感变小,表面更为平滑、致密,几乎没有裂缝,这种均匀一致的高密度小碎片结构可能具有较大的表面粗糙度和比表面积,有利于催化反应.TiO2电极的晶体结构主要为锐钛矿型.稀土的掺入使得晶相所对应的衍射峰强度变弱且峰形宽化,说明适量Ce的掺杂使涂层表面TiO2晶粒细化了.在掺杂比为Ti∶Ce=100∶1·5,热处理温度为450℃,热处理时间为90min时制备的掺杂Ce元素的电极性能最好,此电极对目标有机物COD去除率达到80%,而不掺杂稀土元素的Ti/TiO2电极为阳极时COD去除率在同样时间内仅为62%,说明稀土的掺杂提高了电极催化性能.更多还原

【Abstract】 Ce-doped Ti/TiO2 electrodes were prepared by the sol-gel method. The preparation temperature, time, and Ce doping content were optimized. The electro-catalytic oxidation characteristics of the prepared electrodes were investigated using chemical oxygen demand (COD) degradation of oil-field wastewater as a model compound. Moreover, the relationship between the electrode structure and electro-catalytic properties was analyzed. The micrograph, elemental composition, and structure of the electrode surface were analyzed by SEM, EDX, and XRD. The electrode surface became more smooth and dense, and almost no crack was observed after Ce doping. The uniform high-density structure of the small debris may have a larger surface area and surface roughness, which was in favor of catalytic reactions. The crystal structure of the TiO2 electrode was anatase. Ce doping at a proper proportion can reduce the grain size and enhance the electrical conductivity of the electrodes. The optimized conditions were the temperature of 450 ℃, time of 90 min, and doping amount of Ti∶Ce=100∶1.5. The COD removal rate was up to 80% after 90 min treatment with the electrode doped with Ce, and only 62% with the electrode without Ce.更多还原