Si纳米线/ZnFe_(2)O_(4)/AgBr光催化剂的构建及其磁场可调控性能  

Construction of Si Nanowire/ZnFe_(2)O_(4)/AgBr Photocatalyst and Its Magnetic Field Tunable Performance

作　　者：张仕杰 史超杰 唐继霞 钱图 梁丽丽 李雪辰 田禾[2,3] 贺婕 杨正春[1] ZHANG Shijie;SHI Chaojie;TANG Jixia;QIAN Tu;LIANG Lili;LI Xuechen;TIAN He;HE Jie;YANG Zhengchun(Tianjin Key Laboratory of Film Electronic&Communication Devices,Tianjin University of Technology,Tianjin 300384,China;Tianjin Key Laboratory for Advanced Mechatronic System Design and Intelligent Control,Tianjin University of Technology,Tianjin 300384,China;National Demonstration Center for Experimental Mechanical and Electrical Engineering Education,Tianjin University of Technology,Tianjin 300384,China)

机构地区：[1]天津理工大学天津市薄膜电子与通信器件重点实验室,天津300384 [2]天津理工大学天津市先进机电系统设计与智能控制重点实验室,天津300384 [3]天津理工大学机电工程国家级实验教学示范中心,天津300384

出　　处：《石油学报（石油加工）》2023年第5期1082-1091,共10页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：天津市自然科学基金项目(19JCQNJC06200);天津市重点研发计划项目(22YFYSHZ00280);大学生创新创业训练计划项目(202210060008)资助。

摘　　要：采用金属辅助化学刻蚀法和水热法制备了Si纳米线/ZnFe_(2)O_(4)/AgBr复合光催化剂,考察了Si纳米线/ZnFe_(2)O_(4)/AgBr在磁场作用下的光催化性能。结果表明:Si纳米线/ZnFe_(2)O_(4)/AgBr复合光催化剂在未使用HNO_(3)溶液浸泡且无磁场作用时的光电流密度为0.25 mA/cm^(2),开启电压为0.4 V;Si纳米线/ZnFe_(2)O_(4)/AgBr复合材料在合成时表面会产生Ag,采用HNO_(3)溶液将其浸泡除去Ag,浸泡后光电流密度为0.07 mA/cm^(2),相比于未使用HNO_(3)溶液浸泡时的光电流密度明显下降,这是由于Ag具有传输电子与空穴的能力,可加快ZnFe_(2)O_(4)和Si纳米线间光生电子和光生空穴对的分离,从而提高光电流密度;当外加80000 A/m磁场时,其光电流密度增加至0.2 mA/cm^(2),开启电压为0.28 V,表明磁场可显著提高该复合光催化剂的光催化效率。Si纳米线/ZnFe_(2)O_(4)/AgBr界面处的能带弯曲加快了光生载流子的传输,减少了光生空穴与光生电子间的复合,使更多的电子和空穴可参与到光催化过程中,进而提高了体系的光催化性能。在光催化过程中,外加磁场使体系所产生的光生载流子可以更快速地传输至光催化剂表面,进一步增强体系的光催化效率。Si nanowires/ZnFe_(2)O_(4)/AgBr composite photocatalysts were prepared by metal-assisted chemical etching and hydrothermal method,and the photocatalytic performance of Si nanowires/ZnFe_(2)O_(4)/AgBr under magnetic field were investigated.The results show that in the condition of no HNO_(3)solution and no magnetic field,the photocurrent density of Si nanowires/ZnFe_(2)O_(4)/AgBr composite photocatalyst is 0.25 mA/cm^(2)and the opening voltage is 0.4 V.Ag can be produced on the surface of Si nanowires/ZnFe_(2)O_(4)/AgBr composites during synthesis,and removed by immersion in HNO_(3)solution.The photocurrent density after immersion is 0.07 mA/cm^(2),which is significantly lower than that without immersion in HNO_(3)solution.This attributes to the ability of Ag to transport electrons and holes,which can accelerate the separation of photogenerated electrons and photogenerated hole pairs of ZnFe_(2)O_(4)and Si nanowires,thus improving the photocurrent density.When applying an external magnetic field of 80000 A/m,the photocurrent density is increased to 0.2 mA/cm^(2)and the turn-on voltage is 0.28 V,indicating that the magnetic field can significantly improve the photocatalytic efficiency of composite photocatalyst.The band bending at the Si nanowires/ZnFe_(2)O_(4)/AgBr interface have sped up the transport of photogenerated carriers,and reduced the recombination between photogenerated holes and photogenerated electrons,so that more electrons and holes can participate in the photocatalytic process,thereby improving the photocatalytic performance of the system.In the process of photocatalysis,the external magnetic field enables the photogenerated carriers produced by the system to be transmitted to the surface of the photocatalyst more rapidly,which further enhances the photocatalytic efficiency of the system.

关 键 词：SI纳米线 ZnFe_(2)O_(4)/AgBr 光催化 磁场 光电流密度 能带弯曲 

分 类 号：O472[理学—半导体物理]