Fabrication of highly b-oriented MFI film with molecular sieving properties by controlled in-plane secondary growth

Here we report a facile method to fabricate highly b-oriented and submicrometer thin MFI films on substrates. Neither an anhydrous environment nor a specifically designed structure-directing agent (SDA) is required in the whole process, and by innovation of the secondary growth process, twin growth of the b-oriented seed layer is effectively suppressed with TPAOH as the SDA for the first time. Furthermore, various substrates with different surface conditions can be directly used as substrates without premodification. A Pt electrode also was successfully used as a substrate to grow this high quality MFI film, showing excellent molecular sieving ability in aqueous solution.