School of Materials Science and Engineering, Shenyang University of Technology , Shenyang 110870, P. R. China.
Key Laboratory of Space Applied Physics and Chemistry of Ministry of Education, School of Science, Northwestern Polytechnical University , Xi'an 710072, P. R. China.
ACS Appl Mater Interfaces. 2017 May 31;9(21):18170-18177. doi: 10.1021/acsami.7b02000. Epub 2017 May 16.
A series of ordered mesoporous chromium oxides (CrO) were synthesized by first replicating bicontinuous cubic Ia3d mesoporous silica (KIT-6), then a controlled mesostructural transformation from Ia3d to I432 symmetry during the replication from KIT-6 to CrO was achieved by reducing the pore size and interconnectivities of KIT-6, accompanied with an increase in pore size from 3 to 12 nm and a decrease in framework thickness from 8.6 to 5 nm of the resultant CrO replicas. The gas-sensing behavior of the CrO replicas toward formaldehyde (HCHO) was systematically investigated. Ordered mesoporous CrO with both large accessible pores (12 nm) and an ultrathin framework (5 nm) exhibits the best sensing performance, with a response (R/R = 119) toward 9 ppm of HCHO 4.4 times higher than that (R/R = 27) of its counterpart with small pores and a thick framework. Moreover, it possesses excellent selectivity for detecting HCHO over other interference gases such as CO, benzene, toluene, p-xylene, NH, HS, and moisture. The significantly enhanced sensing performance of ordered large-pore mesoporous CrO with ultrathin framework suggests its great potential for the selective detection of HCHO.
一系列有序介孔氧化铬（CrO）是通过首先复制双连续立方 Ia3d 介孔硅（KIT-6）来合成的，然后在从 KIT-6 复制到 CrO 的过程中，通过减小孔尺寸和连通性来实现从 Ia3d 到 I432 对称的受控介孔结构转变，同时孔尺寸从 3nm 增加到 12nm，骨架厚度从 8.6nm 降低到 5nm。研究了 CrO 复制体对甲醛（HCHO）的气体传感行为。具有大孔（12nm）和超薄骨架（5nm）的有序介孔 CrO 表现出最佳的传感性能，对 9ppm 的 HCHO 的响应（R/R = 119）比具有小孔和厚骨架的对应物（R/R = 27）高 4.4 倍。此外，它对 CO、苯、甲苯、对二甲苯、NH、HS 和水分等干扰气体具有优异的选择性。具有超薄骨架的有序大孔介孔 CrO 显著增强的传感性能表明其在选择性检测 HCHO 方面具有巨大潜力。
