Effect of surface adsorptions of aliphatic alcohols and silver ion on the photocatalytic activity of titania suspended in aqueous solutions
Effect of surface adsorptions of aliphatic alcohols and silver ion on the photocatalytic activity of titania suspended in aqueous solutions
复制标题
脂肪醇和银离子的表面吸附对悬浮在水溶液中的二氧化钛光催化活性的影响
DOI：
10.1021/j100106a018
复制
发表时间：
1993
期刊：
影响因子：
--
通讯作者：
S. Nishimoto
中科院分区：
文献类型：
--
作者：
B. Ohtani;S. Nishimoto
在银盐和脂肪醇的水溶液中，波长>300 nm的光照射在钛（IV）氧化物(TiO[sub - 2]、锐钛矿、TiO[sub - 2](A)和金红石TiO[sub - 2](R)的悬浮液上，导致分子氧（O[sub - 2]）的析出，银金属（Ag）在TiO[sub - 2]表面沉积和醇的氧化。以部分脂肪族醇（甲醇、乙醇、2-丙醇、叔丁醇）和无机、有机银盐为原料，研究了产物的分布。用含有2-丙醇和硫酸银的水悬浮液进行动力学分析。在假设表面吸附底物对光激发电子(e[sup [minus]])-正空穴（h[sup +]）的还原和氧化机制的基础上，分析了悬浮液（C[sub p]）中产物（O[sub 2]、丙酮和Ag）的初始形成速率对2-丙醇浓度的依赖性。该机制意味着在没有适当的表面吸附底物的情况下，该对易于重组。这一机制表明，在没有合适的表面吸附底物的情况下，这对分子可以很容易地重组，这些底物与这对分子反应产生自由活性物质e[sup [minus]]和h[sup +]，并具有足够的能力进行随后的氧化还原反应。可以推测，通过Langmuirian吸附，2-丙醇对表面位置的更多覆盖决定了银离子（Ag[sup +]）的还原捕获所产生的自由h[sup +]的分布。在TiO[sub 2](A)悬浮液中，C[sub p]对速率的依赖性与所提出的机理一致，并获得了一些动力学和吸附参数。参19。， 7个无花果。， 2个标签。«少
Photoirradiation of the light of wavelength >300 nm onto suspensions of titanium (IV) oxide (TiO[sub 2], anatase, TiO[sub 2](A), and rutile TiO[sub 2](R)) in aqueous solution of silver salts and aliphatic alcohols led to the evolution of molecular oxygen (O[sub 2]), the deposition of silver metal (Ag) onto the surface of TiO[sub 2] and the oxidation of alcohols. The product distribution was studied by using some aliphatic alcohols (methanol, ethanol, 2-propanol, and tert-butyl alcohol) and inorganic and organic silver salts. Kinetic analyses were performed with an aqueous suspension containing 2-propanol and silver sulfate. Dependence of the initial formation rates of products (O[sub 2], acetone, and Ag) on the concentration of 2-propanol in suspension (C[sub p]) was analyzed on the assumption of a mechanism including reductive and oxidative trappings of pairs of photoexcited electron (e[sup [minus]])- positive hole (h[sup +]) by surface-adsorbed substrates. The mechanism implies facile recombination of the pair in the absence of the appropriate surface-adsorbed substrates. The mechanism implies facile recombination of the pair in the absence of the appropriate surface-adsorbed substrates, which react with the pair to produce free active species, e[sup [minus]] and h[sup +], with sufficient ability for subsequent redox reactions. It is presumed thatmore » coverage of surface sites with 2-propanol via Langmuirian adsorption determines the distribution of free h[sup +] generated by the reductive trapping by silver ion (Ag[sup +]). The C[sub p] dependence of the rate in TiO[sub 2](A) suspension was consistent with the proposed mechanism and some kinetic and adsorption parameters were obtained. 19 refs., 7 figs., 2 tabs.« less