Preparation method and application of loose nanofiltration membrane for in-situ growth of ZIFs with assistance of polyphenol compounds

The invention discloses a preparation method and application of a loose nanofiltration membrane for in-situ growth of ZIFs with assistance of polyphenol compounds. The preparation method comprises the following steps: (1) preparing two parts of tris (hydroxymethyl) aminomethane (Tris) buffer solutions; (2) preparing a precursor solution and an organic ligand solution: preparing a mixed solution of polyphenol, PEI and a metal ion compound from one buffer solution, and adding an organic ligand into the other buffer solution; and (3) firstly immersing a polysulfone membrane into the precursor solution, then immersing the polysulfone membrane into the organic ligand solution, taking out the polysulfone membrane after reaction, drying the polysulfone membrane in a drying oven, and storing the dried polysulfone membrane in deionized water. The prepared membrane has the characteristics of high interception and high flux, and the nano particles are not easy to fall off after being soaked in water. The method has a wi