Synthesis Of Inorganic Flexible Barium Titanate And Bismuth Ferrite Nanofiber Membranes And Their Piezoelectric Catalytic Propertie

With the development of artificial intelligence and the internet of things,people have higher requirements for electronic devices and other equipment.Lightweight,stretchable,transparent,etc.have increasingly become the development direction of new electronic equipment.However,in the face of realistic demands,there are still some limitations to be solved in the synthesis of flexible functional materials.The limitation is that the common organic or organic-inorganic mixed flexible materials has poor performance compared with functional ceramic.Moreover,the perovskite functional ceramics commonly used in the traditional electronic field are usually not flexible,with high brittleness and strong rigidity,which is one of the important factors restricting the development of flexible electronic devices.Therefore,how to further develop the characteristics of perovskite oxide in flexible equipment has become a new research hotspot.In view of the above-mentioned major problems in the development of flexible functional materials,we selected the most commonly used piezoelectric ceramics barium titanate(BTO)in industrial production,and the typical multi-iron perovskite material bismuth ferrite(BFO)as the basis to explore their flexibilities.On the one hand,based on sintering process of traditional ceramics,combined with the electrospinning technology,we synthesize flexible inorganic perovskite nanofiber membranes through the fibrosis of ceramic materials and the control of grain size.On the other hand,We combined the flexible BTO and BFO fiber membranes with the problem of water purification,and studied the dye degradation performance of BTO and BFO through piezoelectric catalysis.The main research results of this paper are as follows:(1)Inorganic flexible fiber membranes were prepared by electrospinning combined with high-temperature solid-state synthesis.With polyvinylpyrrolidone(PVP)as the organic skeleton,the material is fibrosed by electrospinning.By controlling the sintering temperature,while removing the PVP organic macromolecular skeleton,the grain growth of BTO material is controlled to obtain a smooth fiber structure,and finally a flexible inorganic BTO nanofiber membrane can be obtained.Combined with XRD and SEM data,the macro flexibility performance of materials and the test results of the three-point flexibility test device,the relationship between fiber film flexibility and grain size is explored,and the theory that the control of fiber grain size is the key to the synthesis of flexible fiber film is verified.In addition,we use the synthesized flexible BTO in the field of piezoelectric catalysis,and further improve its piezoelectric catalytic performance by doping Ca element.Relevant experiments show that Ca doped barium titanate(BCTO)has good catalytic degradation performance for Congo red dye,and 7%-BCTO has the best catalytic degradation effect.After 150 minutes,the concentration of Congo red dye is only 4.48% of the original.(2)According to the relevant experience of flexible BTO material synthesis,BFO,which also has perovskite structure,was synthesized by the same means.Through SEM testing and improved two-point flexible testing device,using grain diameter analysis,cantilever stress formula,combined with the actual macro flexibility,the theory that the key to obtain flexible fiber film is to control the grain size is further verified.It is found that BFO sintered at a lower temperature(500℃)has the best flexibility,and the maximum bending strain can reach 0.68%.In addition,through the piezoelectric catalysis experiment,it can be found that BFO also has good piezoelectric catalysis performance for Congo red.Considering the traditional piezoelectric catalysis,it often relies on ultrasound to provide mechanical energy,which seriously limits the practical application of piezoelectric catalysis.However,there is abundant natural mechanical energy in nature,such as wind energy,water energy,etc.,which has huge reserves and is often ignored.Therefore,we use the fish tank circulating water pump to simulate the falling of water flow,and use the water flow to impact the fiber membrane for piezoelectric catalysis.Relevant experiments have proved that flexible BFO is completely feasible for natural water flow catalysis,and can catalyze more than 80% of Congo red dye within 5 hours.