Photoinduced oxygen formation and silver-metal deposition in aqueous solutions of various silver salts by suspended titanium dioxide powder
Photoinduced oxygen formation and silver-metal deposition in aqueous solutions of various silver salts by suspended titanium dioxide powder
复制标题
悬浮二氧化钛粉末在各种银盐水溶液中光诱导氧的形成和银金属沉积
DOI：
10.1039/f19837902685
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发表时间：
1983
期刊：
影响因子：
--
通讯作者：
T. Kagiya
中科院分区：
文献类型：
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作者：
S. Nishimoto;B. Ohtani;H. Kajiwara;T. Kagiya
本文研究了室温下含不同银盐和TiO_2悬浮液的Ar净化水溶液的光化学反应。光照射（λex < 300 nm）导致O2的形成和Ag金属在TiO 2颗粒上的沉积。表观反应速率与银盐的阴离子有关，其大小顺序为ClO-4 < NO-3·SO 2 -4 < F-（PO 3 -4）。金红石[TiO 2（R）]的敏化活性与金红石[TiO 2（A）]的敏化活性相当。沉积的Ag金属与释放的O_2的摩尔比与反应速率无关，等于约100。5，除了TiO 2（A）/AgClO 4的情况。反应混合物的pH值随着照射时间的延长而降低，导致TiO 2失活。虽然在pH < 2时不发生O2形成和Ag-金属沉积，但通过加入NaOH，TiO 2粉末的光敏活性得以恢复。将丙-2-醇添加到失活的TiO 2的酸性悬浮液中对于Ag-金属沉积也是有效的，但对于O2形成不是。
The photochemical reaction of Ar-purged aqueous solutions containing various silver salts and TiO2 powder in suspension has been studied at room temperature. Photoirradiation (λex < 300 nm) resulted in O2 formation and deposition of Ag metal on the TiO2 particles. The apparent reaction rate depended on the anions of the silver salt and increased in the order ClO–4 < NO–3≈ SO2–4 < F–(≈ PO3–4). The sensitizing activity of the rutile [TiO2(R)] was comparable to that of the anatase [TiO2(A)]. The molar ratio of deposited Ag metal to liberated O2, which was independent of the reaction rate, was equal to ca. 5 except for the case of TiO2(A)/AgClO4. The pH of the reaction mixture decreased with irradiation time, resulting in deactivation of the TiO2. Although O2 formation and Ag-metal deposition did not occur at pH < 2, the photosensitizing activity of the TiO2 powder was recovered by the addition of NaOH. The addition of propan-2-ol to the deactivated acidic suspension of TiO2 was also effective for Ag-metal deposition but not for O2 formation.