Controlled Electrospinning Of P3HT Composite Fiber Membrane And Its Photolysis Of Water To Hydrogen Production

Due to the global energy shortage and the intensification of environmental problems,the production and utilization of clean new energy sources such as hydrogen have attracted increasing attention from researchers.The use of semiconductor photolysis of water to produce hydrogen is one of the greenways to obtain clean energy.Compared with inorganic materials,organic semiconductor materials represented by poly（3-hexylthiophene-2,5-dial）(Poly（3-hexylthiophene,P3HT）have the advantages of strong visible light responsiveness,abundant synthetic raw materials,mild reaction conditions,adjustable electronic structure,and optical band gap.However,the hydrogen production performance of single powdered P3HT is extremely low,and it is a feasible scheme in the field of photolysis of water hydrogen production by combining it with the star material,graphite-like carbon nitride（g-C₃N₄）.There are many preparation methods for P3HT-g-C₃N₄ composites,such as the solvothermal method,photoreduction self-assembly method,etc.,but the product morphology of these methods is difficult to control,and the catalytic effect is not ideal.In addition,traditional powdered photocatalysts generally have the problem that they cannot be effectively recovered in liquid media,and film photocatalysts are an effective solution.Electrospinning is widely used because of its advantages of low spinning cost,simple manufacturing device,controllable process,and a wide variety of spinnable substances,and this type of nanofiber membrane is expected to be used in the field of photolysis of water to hydrogen catalysts.Based on the above discussion,we selected P3HT and its mixture with g-C₃N₄ as the spinning liquid,added polymethyl methacrylate（PMMA）as an auxiliary polymer to increase its spinnability,and prepared P3HT/PMMA and P3HT-g-C3N4/PMMA fiber membrane photocatalysts by one-step electrospinning,respectively,and explored the photocatalytic hydrogen production performance of the two by water splitting.The main research contents of the paper are as follows:（1）Single PMMA was used as a spinning liquid for electrospinning to determine the spinning parameters with good fiber morphology.Then,P3HT and PMMA blended solutions were used as spinning liquid,and a series of fiber membrane photocatalysts with different P3HT contents were prepared in one step,and their photocatalytic water-splitting water hydrogen production performance was tested and analyzed.The physical and chemical structure was analyzed by scanning electron microscopy（SEM）,elemental mapping（Mapping）,X-ray photoelectron spectroscopy（XPS）,infrared spectroscopy（FTIR）,and Raman spectroscopy（Raman）.Ultraviolet-visible absorption spectroscopy（UV-vis）showed that P3HT in nanofibers was the photocatalytic active component,and the fiber membrane photocatalyst had the best hydrogen production rate（127μmol/（h·g））when the concentration of P3HT was 4 mg/m L.The results show that P3HT can effectively improve its hydrogen production performance after fibrosis.（2）Fiber membrane photocatalyst was prepared by using g-C₃N₄/PMMA blended solution as spinning liquid,and various test results showed that when the concentration of g-C₃N₄ was 12～20mg/m L,the fiber membrane catalyst could obtain good fiber morphology and hydrogen production effect,and the hydrogen production rate of g-C₃N₄/PMMA fiber membrane photocatalyst was 5.5times that of g-C₃N₄ powder,which once again verified that the fibrosis of powdered photocatalyst was feasible to improve hydrogen production performance.Then,the blended solutions of P3HT,g-C₃N₄ and PMMA were used as spinning liquid to keep the PMMA content unchanged,and a series of composite fiber membrane photocatalysts were prepared by adjusting the ratio of P3HT to g-C₃N₄ in one step,and their physicochemical properties and photocatalytic water splitting water to hydrogen production performance were tested and analyzed.The results of SEM,Mapping,XPS,and FTIR proved the presence of P3HT and g-C₃N₄ in the membrane of composite fibers,and the Raman test results showed that a well-bound P3HT-g-C₃N₄ heterojunction was formed on the fiber.In the photolyzed water test（full spectrum）,when the ratio of P3HT to g-C₃N₄ in the composite fiber membrane is 1:5,the hydrogen production rate of the heterojunction fiber membrane is the highest,up to 7327μmol/（h·g）,which is consistent with the photocurrent test and water contact angle test results.