Preparation And Application Of Titanium Dioxide/Molybdenum Disulfide Composites

In this paper,flower-like TiO₂ microspheres are successfully prepared by solvothermal method using acetic acid as solvent,tetrabutyl titanate as titanium source and polyvinylpyrrolidone?PVP?as dispersant.The controllable synthesis of TiO₂ morphology can be achieved by adjusting the amount of titanium source and dispersant added.The micron-sized framework effectively avoids the aggregation of active nanomaterials,and the assembled nanosheets are thin,which effectively shortens the diffusion path of Li⁺ions and thus promotes the kinetics of Li⁺ion storage.The prepared material has good electrochemical performance,so flower-like TiO₂ microspheres are selected as the framework for supporting MoS₂.By controlling the calcination temperature in nitrogen at 450oC,the PVP is carbonized to enhance the conductivity of TiO₂ microspheres.The prepared flower-like TiO₂/C microspheres are 2³?m and assembled from elongated nanosheets.The TiO₂ crystal form is composed of anatase and TiO₂-B.Compared to anatase and rutile,TiO₂-B is a relatively rare crystalline form and has a high theoretical specific capacity due to its open channels.Therefore,TiO₂-B is more suitable as an electrode material for lithium ion batterys?LIBs?.MoS₂ was loaded on TiO₂/C microspheres by hydrothermal method using ammonium molybdate as molybdenum source and thiourea as sulfur source.Because MoS₂ is limited by the petal space of TiO₂/C microspheres,the growth of MoS₂ is limited,and fish-scale-like MoS₂ nanoplates with a size of approximately 10 nm are obtained.The layer spacing of fish-scale-like MoS₂nanosheets is 0.77 nm,which is larger than that of pure MoS₂?0.63 nm?.The increase of MoS₂ layer spacing also provides more storage space for Li⁺ion storage.At the same time,fish-scale-like MoS₂ nanosheets can provide more active sites for Li⁺ion insertion,which lays a foundation for composite materials used as LIBs negative electrode.In the flower-shaped TiO₂/C/MoS₂ microspheres,TiO₂ acts as an effective backbone for MoS₂ that can effectively minimize the strain of volume changes.The fish-scale-like MoS₂ can provide more active sites for reactions.The as-prepared flower TiO₂/C microspheres,pure MoS₂ nanoflowers and flower-like TiO₂/C/MoS₂microspheres were used as anode electrodes of LIBs for electrochemical test.The flower-shaped TiO₂/C/MoS₂ electrode exhibits a discharge capacity of 621 mAh g^-1 at100 mA g^-1 after 100 cycles,which is much higher than that of TiO₂/C electrode(291mAh g^-1)and pure MoS₂ electrode(160 mAh g^-1).Compared with TiO₂/C and pure MoS₂,the structural and compositional features of the TiO₂/C/MoS₂ microspheres enhanced the specific capacity and cycling stability.In addition,high photocatalytic activity TiO₂ nanosheets with exposed?001?crystal planes were prepared.MoS₂ is loaded on the surface of TiO₂ nanosheets by hydrothermal method.The prepared composite is used for the UV photocatalytic degradation of methyl orange.The results showed that 5 wt%MoS₂/TiO₂ composite material has better photocatalytic effect.Increasing the load of MoS₂,black MoS₂ will absorb a lot of light and shield TiO₂,thereby reducing the photocatalytic effect of the composite.