Abstract Two-dimensional layered double hydroxides (LDH) as a membrane material has tremendous potential in the water treatment field. However, the stability and permeance of the LDH membrane should be further improved for the industrial application. In this study, the LDH separation layer was in situ grown on the tubular Al2O3 substrate. The obtained LDH composite membrane was then calcined to reduce the surface free energy and remove some interlayer anions. Therefore, the calcined LDH composite membrane exhibited enhanced stability and permeance for removing dye molecules from water. The permeance of the calcined LDH membrane reached 367 L m−2 h−1 MPa−1 and the rejection for Eriochrome black T was still above 99%. Moreover, the membrane can maintain the separation performance more than 110 h in the nanofiltration process. The morphologies and structures of the LDH membranes before and after calcination were also investigated. The results indicated that this facile method is effective to improve the separation performance of the LDH membrane.

中文翻译：

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具有增强纳滤性能的层状双氢氧化物膜的煅烧

摘要 二维层状双氢氧化物（LDH）作为一种膜材料在水处理领域具有巨大的潜力。然而，LDH膜的稳定性和渗透性有待进一步提高以实现工业应用。在这项研究中，LDH 分离层是在管状 Al2O3 衬底上原位生长的。然后将获得的LDH复合膜煅烧以降低表面自由能并去除一些层间阴离子。因此，煅烧的LDH复合膜表现出增强的稳定性和从水中去除染料分子的渗透性。煅烧后的 LDH 膜的渗透率达到 367 L m-2 h-1 MPa-1，铬黑 T 的截留率仍高于 99%。此外，该膜在纳滤过程中可保持110 h以上的分离性能。还研究了煅烧前后 LDH 膜的形态和结构。结果表明，这种简便的方法可以有效地提高LDH膜的分离性能。