中文摘要：

采用超声-水热法在溴氧化铋(BiOBr)上负载不同含量氧化石墨来制备石墨烯-溴氧化铋(Gre-BiOBr)复合物,利用X-射线衍射(XRD)、扫描电镜(SEM)、透射电镜(TEM)、紫外可见漫反射(UV-Vis DRS)、荧光分光光度计(PL)、比表面积仪(BET)及红外光谱仪(FT-IR)对不同负载量的Gre-BiOBr进行初步表征.发现BiOBr负载石墨烯前后均为斜四方晶型(JCPDS:78-0348),均为大小500~1 000 nm片层状.在可见光照射下(λ≥420 nm),以罗丹明B(Rhodamine B,RhB)和水杨酸(Salicylicacid,SA)作为降解底物,发现经过负载石墨烯后BiOBr的可见光活性有明显提高,且当负载质量比为10%时,Gre-BiOBr复合物表现出最好的可见光活性,此时光降解RhB反应速率(k10%Gre-BiOBr=0.046 min-1)约为单纯BiOBr(kBiOBr=0.02 min-1)的两倍.经测定10%Gre-BiOBr复合物的比表面积为10.50 m2/g,禁带宽度为2.61 eV,能吸收λ≥475 nm可见光.结合自由基捕获实验,发现该催化体系主要涉及超氧自由基(O2·-)和空穴(h+)的共同氧化作用.10%Gre-BiOBr催化剂循环使用5次,仍保持着良好光催化活性,表明该催化剂稳定性较好.

英文摘要：

Graphene-bismuth oxybromide (Gre-BiOBr)composites with different amounts of graphene loading on BiOBr were prepared by ultrasound-hydrothermal method,named BiOBr,2% Gre-BiOBr,6% Gre-BiOBr,10%Gre-BiOBr and 14%Gre-BiOBr,respectively.The materials were characterized by X-ray diffraction(XRD),scan-ning electron microscopy (SEM),transmission electron microscopy (TEM),ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS),fluorotrophotometer(PL)and Brunauer-Emmett-Teller (BET).The results showed that the as-prepared catalysts were the diagonal square crystal shape(JCPDS card no:78-0348),and the sheet of them were about 500~1 000 nm sheets.Compared with pure BiOBr,the photocatalytic activity of Gre-BiOBr was significantly improved on the degradation of Rhodamine B (RhB)and Salicylicacid(SA)under visible light irradia-tion(λ≥420 nm).The 10%Gre-BiOBr catalyst showed the best photocatalytic activity and the degradation rate of RhB (k10%Gre-BiOBr=0.046 min-1 )was twice than that of pure BiOBr (kBiOBr=0.020 min-1 ).The specific surface area and the band gap (Eg)of 10%Gre-BiOBr catalyst were 10.50 m2·g-1 and 2.61 eV (~475 nm).Based on the free radicals captured experiments,the catalytic mechanism was mainly related to the common oxidation of the super oxygen radical (O2 ·-)and holes (h+).The photocatalytic activity of 10% Gre-BiOBr was excellent in the recycle-usage for five times,so it had good stability.