摘要
通过一步水热法成功地制备了BiOBr/BiPO_(4) p-n异质结复合光催化剂。采用多种表征手段对样品物理属性进行了表征,包括X射线粉末衍射(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)、N2吸附-脱附等温线、X射线光电子能谱(XPS)、紫外可见漫反射光谱(UV-Vis DRS)。样品光催化活性通过可见光(λ>420 nm)降解罗丹明B进行评价,考察了BiPO_(4)含量对所制备光催化材料活性的影响,通过捕获实验确定光催化反应中的主要活性物种,并提出了其光催化机理。研究结果表明,BiPO_(4)的最佳含量(物质的量分数)为10%,此时所制备催化剂活性最好,其反应速率常数为0.14 min-1,约为纯BiOBr的3.7倍,且3次循环使用后仍保持较高的催化活性。催化活性的提高主要由于BiOBr/BiPO_(4) p-n异质结的形成,提高了光生载流子的分离效率,从而提高了光催化活性。同时,对污染物吸附能力的提高也起到促进作用。空穴和超氧基阴离子自由基是光催化过程中的主要活性物种,3种活性物种作用大小依次为空穴>超氧阴离子自由基>羟基自由基。
BiOBr/BiPO_(4) p-n heterojunction composite photocatalyst was successfully prepared by one-step hydrothermal method.The physical properties of the samples were characterized by X-ray powder diffraction(XRD),transmission electron microscope(TEM),scanning electron microscope(SEM),N2 adsorotion-desorption isotherm,X-ray photoelectron spectroscopy(XPS) and UV-Vis diffuse reflection spectmm(UV-Vis DRS).The photocatalytic activity of the sample was evaluated by degradation of rhodamine B under visible light irTadiation(A> 420 nm),and the effect of BiPO_(4) content on the photocatalytic activity of the prepared materials was investigated.The main active species in the photocatalytic reaction were determined by capturing experiment,and the photocatalytic mechanism was proposed.The results showed that the optimum molar content of BiPO_(4) was 10%,and the optimal catalyst showed the best photocatalytic activity with the reaction rate constant of 0.14 min-1,which was about 3.7 times that of pure BiOBr.And it also exhibited amostly unchanged photocatalytic activity after three cycling experiments.The improvement of catalytic activity is mainly due to the formation of BiPO_(4)/BiOBr heterojunction,which improves the separation efficiency of photo-generated carriers.In addition,the enhanced adsorption capacity of pollutants promotes the improvement of catalytic activity.The hole and superoxide radical are the main active species in the photocatalytic process,and the order of the role of the three species is hole> superoxide radical> hydroxyl radical.
作者
陈永胜
郑健飞
朱思龙
熊梦杨
聂龙辉
CHEN Yong‑Sheng;ZHENG Jian‑Fe^(2+)i;ZHU Si‑Long;XIONG Meng‑Yang;NIE Long‑Hui(School of Materials and Chemical Engineering,Hubei University of Technology,Wuhan 430068,China)
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2021年第10期1828-1838,共11页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.51572074)
湖北省绿色轻质材料重点实验室开放课题(No.201907B09,201710A12)
大学生创新创业项目(No.201810500048)资助。
