| In the field of natural science today,catalytic technology is the core of the research.Among them,the photocatalytic technology is a new catalytic technology with highly effective,non-toxic and non-secondary pollution is considered to be one of the most promising technologies to solve the current environmental pollution problems that people encounter,its key depends on the efficient photocatalyst preparation.According to the introduction of different halogen elements（Cl,Br,and I）,there are three main forms of bismuth halide oxide.Among them,the bromine bismuth oxide（BiOBr）photocatalytic materials due to its diverse morphology,big specific surface area and good energy band location etc.,become one of the hot spots in the field of photocatalysis research.However,due to the characteristics of BiOBr nanocrystals themselves,their photocatalytic activity is affected.Therefore,in this paper,it was modified by morphology regulation and heterojunction structure,aiming to improve its photocatalytic performance.The main research contents are as follows:（1）In the case of without using any organic template agent,BiOBr was grown in situ on BC through bio-template method,and three-dimensional BiOBr flower-shaped microspheres composite materials（BiOBr/BC）with high dispersity,anti-aggregation and morphology-controlled were obtained in the three-dimensional cross-linked structure.the average size of BiOBr flower-shaped microspheres from～100 nm to～800 nm can be obtained by adjusting the concentration of Bi3+and CTAB in BC.Using rhodamine B（Rh B）as the target pollutant,the photocatalytic degradation performance of the prepared materials was tested.The results showed that:the BiOBr size～200-500 nm in BiOBr/BC-10 plays the best degradation performance under visible light.The catalyst has the potential advantages of strong anti-aggregation,strong dispersibility,easy recovery and improved catalytic performance.Moreover,the synthesis route using the biometer-template method as the semiconductor catalyst provides a platform for the further design of bismuth bromoxide composite photocatalyst.（2）The BiOBr/BC composite catalyst obtained in the first part of the work was placed in N2atmosphere,by the method of high temperature calcination,in the absence of any reducing agent,the crosslinked 3D network structure of BC is calcined in an inert atmosphere to produce low carbon compounds with reduction effect,and the BiOBr in BiOBr/BC material is ingeniously reduced to Bi elemental material,while the carbonization of BC itself forms carbon fiber（CBC）with good conductivity,and successfully constructed the metal/semiconductor/non-metallic ternary heterojunction（Bi/BiOBr/CBC）.Taking malachite green（MG）as the target pollutant,the photocatalytic degradation performance of the prepared material was tested.The experimental results show that:the transformation of BiOBr morphology in the composite material effectively enhanced the specific surface area of the material,In addition,the specific surface area of Bi/BiOBr/CBC-300-60 was51.06 m2·g-1,which was 1.7 times of BiOBr and 9 times of BiOBr/BC,respectively.The obtained Bi/BiOBr/CBC-300-60 catalyst has the best degradation performance for malachite green（MG）dye under visible light,and is better than pure BiOBr and BiOBr/BC.The catalyst obtained has the advantages of high light absorption range,high specific surface area,many light/transfer paths and high catalytic activity.It provides a synthesis strategy for nano-catalyst with 2D layered structure and expanding the synthesis means of composite photocatalyst based on BiOBr.（3）inspired by the second part,come up with new way to modified BiOBr by constructing metal/semiconductor/semiconductor ternary heterojunction.Through the hydrothermal method according to different Mo:S ratio obtained 2H-Mo S2and 1T@2H-Mo S2catalysts,respectively.The1T@2H-Mo S2/BiOBr composite photocatalysts were prepared by simple hydrothermal method with main BiOBr,as a comparison,2H-Mo S2/BiOBr nanocatalyst was prepared.Taking malachite green（MG）and rhodamine B（Rh B）as the target pollutants to test the photocatalytic degradation performance of the prepared materials.The experimental results show that:compared with pure BiOBr and 2H-Mo S2/BiOBr composites,1T@2H-Mo S2/BiOBr composites have better adsorption and degradation performance for Rhodamine B,and higher photocatalytic degradation performance for malachite green.Meanwhile,1T@2H-Mo S2/BiOBr-5 can still maintain about86%degradation efficiency after four cycles with good stability.This work aim to improve the performance of photocatalytic degradation of dye wastewater,the catalyst obtained has wide light absorption range,high specific surface area and high catalytic activity. |
