Construction And Mechanism Of Efficiently Piezoelectric Catalysis And Pyroelectric Catalysis Of Barium Titanate Nanomaterials For Dye Degradation

With the development of modern industry,increasingly serious environmental problems such as global warming and pollution have become the focus of attention of researchers.In particular,the soluble organic pollutants produced in the printing and dyeing industry are toxic and difficult to decompose,which harm the environment and human life.Through the work of researchers so far,we have found that semiconductor photocatalysis technology is feasible for solving environmental problems caused by organic pollutants.However,although visible light is clean,cheap and renewable,photocatalysis also has some disadvantages,such as low utilization of solar energy,low light transmittance of dark dyes,and rapid recombination rate of carriers,which limit its commercial application.Therefore,it is necessary to find a repeatable method to decompose wastewater under dark conditions.The previous research of our group used the pyroelectric and piezoelectric effects of barium titanate（BaTiO₃）ferroelectric materials to achieve pyroelectric and piezoelectric catalytic degradation of dye wastewater,which brought a new way for dye degradation.How to further improve the piezoelectric catalytic and thermal release catalytic dye degradation performance of barium titanate is the key to its practical application in the future.Improving the efficiency of carrier migration and separation is the technical core of improving the performance of piezoelectric catalysis and pyrocatalytic dye degradation.This work studies the methods of constructing heterojunctions,element doping,and conductive graphite powder to improve the efficiency of carrier migration and separation,and improve its catalytic activity and dye degradation performance.Specifically::1)Constructing a BaTiO₃/g-C₃N₄heterojunction;2)Doping with Fe elements;3)Mixing with graphite powder.The main research contents are as follows:1.Construct the piezoelectric catalysis of BaTiO₃/g-C₃N₄heterojunctionThe composite nanomaterials of barium titanate and carbon nitride are prepared.And then the material structure heterojunction on its piezoelectric catalytic degradation of Rh B dye solution performance was studied.Experiments show that the composite material exhibits enhanced vibration catalytic activity.Compared with the 57%degradation rate of pure BaTiO₃,the composite material has a degradation rate of 82%.This study shows that constructing a heterojunction can significantly improve the piezoelectric catalytic performance of BaTiO₃.The enhancement is attributed to the fact that the electric field in the heterojunction effectively separates the carriers caused by vibration and further accelerates the carrier migration.2.Piezoelectric catalysis of Fe-doped BaTiO₃nanofibersThe Fe-doped BaTiO₃nanofibers were prepared,and the influence of different doping amounts on its pressure catalytic performance was studied.Under vibration excitation,the vibration catalytic dye decomposition rates of pure BaTiO₃and 2%Fe-doped BaTiO₃are70.4%and 98.9%,respectively.The improvement mechanism of Fe-doped BaTiO₃piezoelectric catalytic performance may be due to the fact that the doping of Fe element helps to increase the electrical conductivity and reduce the number of recombination centers,thereby prolonging the life of carriers.3.Pyroelectric catalysis of BaTiO₃mixing graphite powder in different ratiosBy thoroughly mixing BaTiO₃with graphite powder,the performance of its pyroelectric catalytic degradation of Rh B dye solution was studied.Applying a 30-52℃thermal cycle,the degradation rate of BaTiO₃and BaTiO₃+5 wt%C to Rh B dye reached17.8%and 78.6%,respectively.The experimental results show that the pyroelectric catalytic performance of barium titanate is significantly improved after mixing graphite.The reason is that graphite has a transfer effect on negative charges.During the catalytic process,the charge generated by BaTiO₃is separated by C on the surface,reducing the recombination of charges.,Improve the pyroelectric catalytic performance of the material.