Method for manufacturing photocatalytic filter having porous nanofiber heterostructure

A method for preparing a porous nano-fiber heterostructure photocatalytic filter screen, wherein the method comprises the following steps:

• step I:
• preparing a photocatalytic heterostructure consisting of a plasmonic metal nanostructure with tunable visible to infrared band spectra and a semiconductor nanostructure,
• 1-1) centrifuging a solution containing the plasmonic metal nanostructure with the tunable visible to infrared band spectra, removing a capping agent on a surface of the solution, and preparing an initial solution a with a concentration of 0.1-20 mol/L of the plasmonic metal nanostructure;
• 1-2) centrifuging a semiconductor nanostructure solution, removing a capping agent on a surface of the solution to redisperse in deionized water, and preparing an initial solution b with a concentration of 0.1-10 mol/L of the semiconductor nanostructure;
• 1-3) dissolving surface ligand molecules in deionized water to prepare an initial solution c with a concentration of 0.2-20 mol/L of the surface ligand molecules;
• 1-4) mixing the initial solution b and the initial solution c and fully stirring them, wherein the surface ligand molecules are absorbed on a surface of a photocatalytic material, centrifuging, removing excessive surface ligand molecules, and redispersing in the deionized water to obtain a mixed solution d;
• 1-5) mixing the initial solution a and the mixed solution d and fully stirring them, ensuring that plasmonic metal nanostructures with tunable spectra in the mixed solution d and the initial solution a are fully absorbed, and finally forming a heterostructure solution e consisting of the plasmonic metal nanostructures with tunable spectra and semiconductor nanostructures that are randomly combined;
• step II:
• preparing an electrospinning solution
• dissolving the heterostructure solution e, a high molecular organic polymer, and an amphiphilic polymer organic polymer in a mono-component or multicomponent organic solvent, stirring at a room temperature to obtain a colorless transparent solution f with 6%-20% the high molecular organic polymer by mass, adding a large-size metal nanoparticle solution with a molar concentration of 0.0001-1 mol/L, and continuously stirring to obtain the electrospinning solution g that is colorless transparent;
• step III:
• preparing a porous, large-area filter screen
• taking the electrospinning solution g into a glass syringe, removing bubbles therein, loading the electrospinning solution g on an injection card slot of an electrospinning device, and cutting an aluminum foil to cover a receiving roller;
• turning on a power supply of the electrospinning device and set basic parameters, wherein a rotating speed of the receiving roller is 10-1000 rpm/min, a syringe needle is 5-20 cm away from the roller, a positive high voltage is set to 5-30 kv, a negative high voltage is set to 1-3 kv, an injection speed is set to 0.1-3 ml/h, and a spinning time is 0.01-24 hours, turning off the power supply after spinning is finished, taking off the aluminum foil and drying in a vacuum drying oven to obtain a composite polymer fiber structure;
• soaking the aluminum foil loaded with fiber in the deionized water for 0.1-48 hours, dissolving the amphiphilic polymer organic polymer in the deionized water, taking out the aluminum foil, heating and air-drying to obtain an air purification filter screen structure with a diameter of 10-100 μm, a length of 10-10000 μm and a porosity of 1-99%.