Ultrathin Amorphous Silica Membrane Enhances Proton Transfer across Solid-to-Solid Interfaces of Stacked Metal Oxide Nanolayers while Blocking Oxygen
Ultrathin Amorphous Silica Membrane Enhances Proton Transfer across Solid-to-Solid Interfaces of Stacked Metal Oxide Nanolayers while Blocking Oxygen
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DOI：
10.1002/adfm.201909262
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发表时间：
2020-02-06
影响因子：
19
通讯作者：
Frei, Heinz
中科院分区：
文献类型：
--
作者：
Jo, Won Jun;Katsoukis, Georgios;Frei, Heinz
利用电化学阻抗谱和傅里叶变换红外反射吸收光谱（FT-IRRAS）研究了在叠层金属氧化物纳米膜中插入无定形二氧化硅层后，固体-固体界面的质子转移速率的大幅度提高.通过原子层沉积（ALD）制备的Co 3 O 4、SiO2和TiO 2的三重堆叠纳米层能够实现2400 +/- 60 s（-1）nm（-2）（pH 4，室温）的质子通量，而单个TiO 2（5 nm）层表现出低三倍的830 s（-1）nm（-2）的通量。基于FT-IRRAS测量，提出这种显着的增强源于夹心二氧化硅层形成界面SiOTi和SiOCo连接到TiO 2和Co 3 O 4纳米层，分别与O桥提供快速的H+跳跃路径的固体-固体界面。连同2 nm ALD生长的SiO2层的完全O-2不渗透性，跨多堆叠金属氧化物层的质子传输的高通量开启了不相容催化环境的整合，以形成功能性纳米级组件，例如用于通过H2O还原CO2的人工光系统。
A large jump of proton transfer rates across solid-to-solid interfaces by inserting an ultrathin amorphous silica layer into stacked metal oxide nanolayers is discovered using electrochemical impedance spectroscopy and Fourier-transform infrared reflection absorption spectroscopy (FT-IRRAS). The triple stacked nanolayers of Co3O4, SiO2, and TiO2 prepared by atomic layer deposition (ALD) enable a proton flux of 2400 +/- 60 s(-1) nm(-2) (pH 4, room temperature), while a single TiO2 (5 nm) layer exhibits a threefold lower flux of 830 s(-1) nm(-2). Based on FT-IRRAS measurements, this remarkable enhancement is proposed to originate from the sandwiched silica layer forming interfacial SiOTi and SiOCo linkages to TiO2 and Co3O4 nanolayers, respectively, with the O bridges providing fast H+ hopping pathways across the solid-to-solid interfaces. Together with the complete O-2 impermeability of a 2 nm ALD-grown SiO2 layer, the high flux for proton transport across multi-stack metal oxide layers opens up the integration of incompatible catalytic environments to form functional nanoscale assemblies such as artificial photosystems for CO2 reduction by H2O.