Preparation of novel protonated forms of the ion-exchangeable layered perovskite via selective reaching of bismuth oxide sheets and their application to photocatalytic activities

通过酸性处理选择性Leaching of the Aurivillius phases Bi_2ANaNb_3O_<12>（A=Ca or Sr，Bi_2CaNaTa_3O_<12>）和可交换层perovskite的protonated forms of ion-exchangeable layered perovskite prepared from这些Aurivillius phases通过选择性Leaching of bismuth oxide sheets。光催化活性基于H_2进化的行为（含有20%的乙醇）下的紫外线辐射。Aurivillius phase没有显示H_2进化的活动，但当原始形式展示光催化活性时。紫外-可见性差异反射作用特别是指选择性地从双螺杆氧化物表中提取出来以改变电气结构。H_2演变后的原始形式的XRD模式显示了中间层距离的增量，并指示了H_2演变期间中间层空间的有效使用。因此，不同的是。 ... More Aurivillius相位和原始形式之间的光催化活动行为可归因于在条件带底部的位置和/或通过选择性延伸的双氧化物薄片导致表面区域的增加。为新颖的双层钨酸进行酸性处理。任何结构都与不可互换的分层的超声波结构相似。XRD、ICP和TG的分析如良好的TEM观测显示了双氧化物片的选择性延伸，表明了新的钨酸、H_2W_2O_7·nH_2O的形成，可能被充分地展示了光催化活性。分层超氧化物和酒精的原始形式的反应。自从n-酒精通常被用作光催化H_2从水中演变的一种破坏性试剂。我们研究了在可互换分层perovskite HCa_2Nb_2O_<10>·xH_2O和n-酒精之间的相互作用。HCa_2Nb_2O_<10>·xH_2O与n-酒精导致形成HCa_2Nb_2O_<10>·xH_2O的alkoxy-derivatives的形成，以实现高光催化活性，我们探索了一种新的pillaring方法来利用分层过氧化物的有机衍生物。当我们对CH_2=CH（CH_2）_nO衍生物（n=3，8）的HLaNb_2O_7·xH_2O对氢氯硅烷和寡硅烷、XRD、IR和核磁共振分析显示了中间层空间中羟基化的分布情况，并表明羟基化是可用的。Less（低）

Photocatalytic activities of the protonated forms of ion-exchangeable layered perovskites.We investigated the photocatalytic activities of the Aurivillius phases Bi_2ANaNb_3O_<12> (A=Ca or Sr,Bi_2CaNaTa_3O_<12> and the protonated forms of ion-exchangeable layered perovskite prepared from these Aurivillius phases via selective leaching of bismuth oxide sheets by acid treatment. Photocatalytic activities were estimated based on H_2 evolution behavior from aqueous ethanol solutions (containing 20% ethanol) under UV irradiation. Aurivillius phases showed no activities for H_2 evolution, while the protonated forms exhibited the photocatalytic activities. UV-Vis diffuse reflectancee spectra indicated that selective leaching of bismuth oxide sheets led to the change in electric structure. XRD patterns of the protonated forms after H_2 evolution showed the increase in the interlayer distance, indicating the effective use of the interlayer space during H_2 evolution. Therefore, the difference i … More n the photocatalytic activity behavior between the Aurivillius phases and the protonated forms is attributable to the change in the position of the bottom of the conduction bands and/or the increases in surface area caused by the selective leaching of bismuth oxide sheets.Preparation of novel double-layered tungstic acid.We conducted acid treatment of an Aurivillius phase, Bi_2W_2O_9, whose structure was similar to that of ion-exchangeable layered perovskite. XRD,ICP and TG analyses as well as TEM observation showed the selective leaching of the bismuth oxide sheets, indicating the formation of the novel tungstic acid, H_2W_2O_7・nH_2O, which could potentially exhibit the photocatalytic activities.Reaction of the protonated forms of layered perovskite and alcohols.Since the n-alcohol is generally used as a sacrificial reagent for photocatalytic H_2 evolution from water, we investigated the interaction between the protonated forms of ion-exchangeable layered perovskite HCa_2Nb_2O_<10>・xH_2O and n-alcohol. The reaction of HCa_2Nb_2O_<10>・xH_2O with n-alcohols led to the formation of alkoxy-derivatives of HCa_2Nb_2O_<10>・xH_2O.To achieve high photocatalytic activities, we explored the new pillaring method using organic derivatives of layered perovskite. When we conducted the reaction of CH_2=CH(CH_2)_nO- derivatives (n=3,8) of HLaNb_2O_7・xH_2O with hydrochlorosilanes and oligosiloxanes, XRD,IR and NMR analyses showed the occurrence of hydrosilylation in the interlayer space, indicating that hydrosily lation is utilizable for pillaring. Less