二氧化钛光催化还原银离子探针反应的研究

探讨了以微量银离子为光化学反应的探针,依据金属离子光催化还原反应评价催化剂的光催化活性的方法.选择晶粒度为25nm的锐钛矿二氧化钛为研究对象,研究了紫外光照射下此催化还原反应的反应动力学特性,考察了二氧化钛浓度和银离子浓度对光催化反应速率的影响,确定了适合该评价方法的优化操作条件,并通过TEM和XRD等手段对反应后的固体颗粒物进行了表征.结果表明,在254nm的紫外光照射下,二氧化钛光催化还原银离子具有一级反应动力学特征,水溶液中的银离子在二氧化钛表面发生还原生成单质银.评价二氧化钛活性的优化操作条件为二氧化钛浓度为0.4g/L,银离子初始浓度为10~15mg/L时.检测了4种不同粒径二氧化钛的光催化活性,结果表明银离子适合作为光催化反应的探针.

Photocatalytic Reduction of Silver Ion Probe on Nano Titanium Dioxide

Photocatalytic performance was evaluated which was based on photocatalytic reduction of silver ion which was chosen as a probe in this work.Choosing the anatase titanium dioxide with grain size of 25 nm as the research object,the kinetics of photocatalytic reduction reaction were studied under UV irradiation and the influence on photocatalytic reaction rate of the concentration of the titanium dioxide and silver ion.The results showed that the reaction of the photocatalytic reduction of silver ions reflected the kinetics of the first-order reaction under the UV irradiation of 254 nm.The elemental silver was obtained through the reduction of silver nitrate with nano titanium dioxide.The optimal condition was the concentration of the nano titanium dioxide was0.4g/L and the concentration of the silver ion was 10~15mg/L.Under this condition,the photocatalytic activity was examined by employing four totally different sizes of nano titanium dioxide.It has been proved that the silver ion was a suitable probe for photocatalytic reduction reaction.