Redox Reaction Synthesis Of Bi Based Nanocomposites With Photocatalytic And Electrochemical Performance

With the improvement of people's living standards and economic rapid development,the environmental pollution and resources shortage have huge challenges for human beings.Photocatalytic technology can utilize solar energy in the degradation of the environment harmful substances,high energy density lithium ion batteries as a form of energy storage have wide application in life.Therefore,effective use and conversion of solar energy and the development of other new energy have become an effective way to solve these two problems.Because of its unique layered structure,good optical performance and low cost,bismuth based materials have attracted great interest,and have showed great application prospect in the photocatalytic degradation of organic pollutants and the promotion of energy storage and conversion.In this paper,a series of Bi-based nanocomposite have been designed and synthesized via an oxidation-reduction method.Through the construction of heterojunction structure,photocatalytic composite can promoted the effective separation of photogenerated charge and enhance the photocatalytic efficiency.BiOCl/MnO_x and Bi₂O₂CO₃/MnCO₃ nanocomposites were prepared by redox reaction using KMnO₄ as oxidizing agent.Bi₂O₃/MnO_x nanocomposites have been obtained through the calcination of Bi₂O₂CO₃/MnCO₃ at 500°C.The prepared composites have been used as anode materials for lithium secondary battery.AgBr quantum dots coupled porous BiOBr spheres have been successfully synthesized via a three-step route.Porous Bi spheres were firstly prepared through a facile solvothermal method employing ethylene glycol as reducing agent.Sequentially,a redox reaction of Bi spheres with NH4Fe?SO₄?2 as oxidizer was employed to prepare porous BiOBr spheres.Finally AgBr quantum dots were loaded on BiOBr spheres through in situ precipitation method.The obtained products were characterized by x-ray powder diffraction?XRD?and transmission electron microscopy?TEM?.The as-prepared three dimensional BiOBr hierarchical miscospheres with diameter of ca.500 nm were fabricated by numerous two dimensional interlaced nanosheets.AgBr quantum dots were dispersed on the surface of BiOBr petals and did not change the microstructures and morphology of host Bi OBr.BiOBr/AgBr composite possesses higher photocatalytic activity than pure BiOBr porous spheres in degrading RhB dyes.BiOCl/MnO_x composites have been successfully synthesized via redox reaction of Bi spheres with KMnO₄ as oxidizer.The obtained products BiOCl/MnO_x composites were characterized by x-ray powder diffraction?XRD?,scanning electron microscope?SEM?and transmission electron microscopy?TEM?.In addition,the electrochemical properties of BiOCl/MnO_x composite have been explored.Experimental results showed that BiOCl/MnO_x composite was made up of some balls constructed by the assemble of nanopieces and some irregular flakes.With the increment of KMnO₄ content,BiOCl/MnO_x composites in irregular flakes gradually reduced,while the self-assembly sphere-like structure gradually increased.The morphology and size became more uniform.With the increase of KMnO₄ content,storage capacity and cycle stability of the BiOCl/MnO_x composite materials have become better.Bi₂O₂CO₃/MnCO₃ composite have been successfully synthesized via redox reaction of Bi spheres with KMnO₄ as oxidizer,and Bi₂O₂CO₃/MnCO₃ composites can be converted into Bi₂O₃/MnO_x composite materials through calcination at 500 °C.The obtained products Bi₂O₂CO₃/MnCO₃ and Bi₂O₃/MnO_x composites were characterized by x-ray powder diffraction?XRD?,scanning electron microscope?SEM?and transmission electron microscopy?TEM?.The electrochemical properties of Bi₂O₂CO₃/MnCO₃ and Bi₂O₃/MnO_x composite have been explored.The experimental results showed that Bi₂O₂CO₃/MnCO₃ composite was composed of some flake balls and a little of cube structure.With the increase of amount of KMnO₄,samples will appear smaller microspheres and nanowires.Bi₂O₃/MnO_x composite has become more porous after calcination.Compared with Bi₂O₂CO₃/MnCO₃ composite material,Bi₂O₃/MnO_x had better reversibility.As the increase of KMnO₄ content,sample had better storage capacity and cycle stability.