氨化改性Sr_(2)Ta_(2)O_(7)/SrTa_(4)O_(11)光催化剂用于光电催化性能研究  

Study on photoelectrocatalysis performance of ammoniamodified Sr_(2)Ta_(2)O_(7)/SrTa_(4)O_(11) photocatalysts

作　　者：黄鹤[1] 徐京城[1] HUANG He;XU Jingcheng(School of Materials and Chemistry,University of Shanghai for Science and Technology,Shanghai 200093,China)

机构地区：[1]上海理工大学材料与化学学院,上海200093

出　　处：《有色金属材料与工程》2022年第2期30-35,共6页Nonferrous Metal Materials and Engineering

基　　金：上海理工大学医工交叉项目(21ZR1444200);国家自然科学基金青年科学基金项目(51602197)。

摘　　要：以钽酸锶同素异质结Sr_(2)Ta_(2)O_(7)/SrTa_(4)O_(11)(STO)为原始材料,采用高温氨化法对原始材料做氮掺杂改性处理,得到了新型氮掺杂钽酸锶同素异质结材料Sr_(2)Ta_(2)O_(7−x)N_(x)/SrTa_(4)O_(11−x)N_(x)(STON),并对其光电催化性能进行研究。结果显示,对比改性前的STO,STO-N具有更强的可见光吸收能力。紫外可见漫反射光谱证明,氮掺杂使得STO的吸收阈值从319 nm红移到485 nm,相应的带隙由3.97 eV减小到2.51 eV,这主要是由于N 2p和O 2p轨道的混合作用导致价带顶部上移。性能测试结果表明:STO-N_(20)的光电催化性能提升最为显著,在施加0.7 V偏压下,STON_(20)电极测得的光电流密度达到了570 nA/cm^(2),是STO电极的光电流密度(8.6 nA/cm^(2))的66倍。根据推算出的STO及STO-N_(20)的能带结构可知,STO-N_(20)性能提升的原因是禁带宽度变窄。Using the strontium tantalate allotropic heterojunction Sr_(2)Ta_(2)O_(7)/SrTa_(4)O_(11)(STO)as the original material,a new type of nitrogen-doped strontium tantalate allotropic heterojunction material Sr_(2)Ta_(2)O_(7−x)N_(x)/SrTa_(4)O_(11−x)N_(x)(STO-N)was obtained by high temperature ammonia modification of the original material,and its photoelectrocatalysis performance was studied.The result shows that compared with STO,STO-N shows a stronger visible light absorption capacity.UV-vis DRS result certifies that nitrogen doping makes absorption threshold of the compound redshift from 319 nm to 485 nm,and the corresponding band gap reduces from 3.97 eV to 2.51 eV,which is mainly due to the upward shift of the valence band top caused by the mixing effect of N 2p and O 2p orbitals.The performance test results show that the photocatalytic performance of STO-N_(20) is improved the most significantly.Under the bias voltage of 0.7 V,the photocurrent density measured by STO-N_(20) electrode reaches 570 nA/cm^(2),which is 66 times that of STO electrode(8.6 nA/cm^(2)).According to the calculated energy band structures of STO and STO-N_(20),the reason for the improvement of STO-N_(20) performance is the narrowing of the band gap.

关 键 词：钽酸锶同素异质结 氮掺杂 可见光 光电流响应 

分 类 号：TB32[一般工业技术—材料科学与工程]