Preparation And Properties Of Bismuth Oxyhalide Composite Photocatalyst And The Study Of Visible-light Photocatalytic Degradation Of Dyes

Bismuth oxyhalides?BiOX,X=Cl,Br,I?,having outstanding optical and electrical properties,are a kind of green semiconductor materials with great photocatalytic potential,and the exploitation of new visible-light photocatalyst centered on which has become a new hot spot in the related fields.At present,in order to achieve effective application of visible-light photocatalysis,microstructure modulation,heterologous hybridization and structural design are most conducted methods in improving photocatalytic performance of bismuth oxyhalides.This dissertation,from the view of microstructure modulation,using citric acid as modulating agent,BiOCl microspheres were successfully prepared via an ethylene glycol solvothermal method and metal bismuth was also generated on its surface by reductive reaction forming Bi@BiOCl composite microspheres.Compared to BiOCl microflowers,Bi@BiOCl composite microspheres were assembled by nanosheets with smaller size,therefore showing larger specific surface area,higher optical absorptivity and better charge transfer property,which achieved improved visible-light photocatalytic performance up to 6 times.In the visible-light photodegradation of RhB?10 mg/L,100 mL?,50 mg of the best photocatalyst could achieve 100%degradation rate in 50 min(4.72 h^-1).From another view of heterologous hybridization,this dissertation,via an ethylene glycol solvothermal method,successfully prepared flowerlike BiOCl/BiOI which was further composited with reduced graphene oxide?rGO?forming BiOCl/BiOI/rGO composite photocatalyst.Owe to the outstanding electronic conductivity of rGO,the recombination rate of photogenerated electron-hole pairs was effectively reduced,achieving enhancement of the photocatalytic performance of the photocatalyst.This study also found that the addition of graphene oxide?GO?precursor,due to the effect of surface functional groups,would affect the morphology of the photocatalyst forming a hollow flowerlike structure,which was beneficial to the light absorbance of the photocatalyst.In the visible-light photodegradation of RhB?10 mg/L,100 m L?,25 mg of the best photocatalyst could achieve 100%degradation rate in 5 min(0.4790 min^-1).This dissertation aims to achieve modulatable preparation and scale application of bismuth oxyhalides?BiOX,X=Cl,Br,I?photocatalysts.Through two different routines,the modulation of morphology,heterologous hybridization and improvement of visible-light photocatalytic performance of the photocatalysts were simultaneously achieved.Moreover,the formation process of the as-prepared materials photocatalysts were carefully analyzed.which were of enlightening significance for the development of related researches and works.