Metal doped g-C3N4 based visible light catalysis flat plate type ultra-filtration membrane and preparation method

Abstract

The invention discloses a metal doped g-C3N4 based visible light catalysis flat plate type ultra-filtration membrane and a preparation method and belongs to the technical field of membrane separation. The method comprises the following steps: adding 8.0%-20.0% (w / w) of polysulfone or polyether sulfone, 5.0%-15.0% (w / w) of pore-foaming agent, 0.05%-2.0% (w / w) of surface active agent, 0.05%-5.0% (w / w) of metal doped g.C3N4 and 58.0%-86.9% (w / w) of solvent into a three-necked round-bottom flask in a certain sequence; stirring and dissolving for 5-16 hours at 30-80 DEG C till fully dissolving; standing by and de-foaming for 8-24 hours, thereby preparing a casting membrane solution; and adopting a phase inversion method for wiping the membrane on a clean glass plate, thereby preparing the visible light catalysis flat plate type ultra-filtration membrane. The visible light catalysis flat plate type ultra-filtration membrane prepared according to the method disclosed by the invention has the advantages that the pure water flux is more than or equal to 450L / m<2>.hr.0.1MPa; the reject rate of bovine serum albumin is more than or equal to 90.00%; the degrading removal rate of fulvic acid can reach about 65% (running for 1 hour under the simulated visible light); and the antifouling property and the visible light catalysis property are excellent. The metal doped g-C3N4 based visible light catalysis flat plate type ultra-filtration membrane is especially suitable for water treatment of micro-polluted water source, pretreatment of sea water desalination and treatment and recycling of wastewater in the fields of biology, chemical industry and medicines.

Description

technical field [0001] The invention relates to a polymer mixed matrix ultrafiltration membrane and a preparation method thereof, in particular to a metal-doped g-C 3 N 4 Visible light catalytic flat-plate ultrafiltration membrane and preparation method thereof. Background technique [0002] The scarcity of water resources and increasingly serious water pollution have become bottlenecks restricting social progress and economic development. The development of new water sources and the utilization of waste water resources have also become issues of global concern. Due to the extremely rich water resources in Shanghai and the large amount of waste water generated, the recycling of sewage and seawater desalination have become strategic choices to solve the water resource crisis. Among many sewage resource technologies, membrane separation technology is one of the best choices. [0003] Mixed matrix membrane, also known as hybrid membrane, is a membrane formed by chemical cros...

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Problems solved by technology

[0004] Chinese patent CN104383821A uses graphene oxide to support magnetic particles with a core-shell structure @TiO 2 The modified separation membrane was prepared, and it was considered that the separation membrane showed good photocatalytic degradation performance and anti-protein pollution performance for the target pollutant bovine serum albumin, but the separation performance and visible light catalytic degradation performance of the prepared membrane were not clarified in the patent application advantages and disadvantages, and the preparation process of the separation membrane is complicated; at the same time, the magnetic particles @TiO 2 The preparation method is complicated and the cost is high

Chinese patent CN102989329A passed AgNO 3 、TiO 2 Blending modification to prepare ultrafiltration membranes, in fact, mainly uses AgNO 3 Visible light catalytic activity, and the degradation rate is relatively slow (in the patent, the degradation rate of methylene blue is characterized by light for 10 hours), and it is impossible to prepare a separation membrane for separation and visible light catalysis at the same time; 3 PO 4 / TiO 2 Complex (Ag 3 PO 4 Nanoparticle deposition onto TiO 2 Surface) and polyvinylidene fluoride materials are blended and modified, so that the modified film has visible light catalytic antibacterial and antifouling properties, mainly using the deposited on TiO 2 Ag on the surface 3 PO 4 Particles degrade the organic matter adsorbed during the application of the separation membrane to reduce membrane fouling, and have not been used to prepare a separation membrane with both separation and visible light catalytic properties; at the same time, neither of these two patents has a synergistic effect to make full use of silver salts and TiO 2 The catalytic performance of silver salt or silver salt and TiO is only utilized by blending or deposition 2 Respective catalytic activity, visible light catalytic efficiency is low

[0006] The present invention is passed in g-C 3 N 4 Doped with metal salts to give full play to metal salts and g-C 3 N 4 synergistic effect to further increase g-C 3 N 4 Visible light catalytic activity, and using metal doped g-C 3 N 4 Improving the visible light catalytic properties of polymer ultrafiltration membranes and preparing planar mixed matrix ultrafiltration membranes with visible light catalytic activity have not been reported in the literature at home and abroad