A/B位计量比对脉冲电流促进钙钛矿溶出行为的影响
Influence of A/B stoichiometry ratio on exsolution behavior of pulsed electric current promoted perovskite
付星 1齐锦刚 1孙立 2于文雯 1胡昕 1商剑 1唐立丹 1赵作福1
作者信息
- 1. 辽宁工业大学材料科学与工程学院,辽宁锦州 121000
- 2. 铁岭龙鑫钛业新材料有限公司,辽宁铁岭 112000
- 折叠
摘要
以(La0.7Sr0.3)xTi0.93Co0.07O3钙钛矿氧化物为基体活性材料,使用PEC(脉冲电流)处理技术,在600 V-3 Hz的脉冲参数下90 s内制得溶出型钙钛矿氧化物.正常化学计量下的ABO3(钙钛矿型氧化物)中A位与B位摩尔比为nA/nB=1,结合A位缺位(x=0.8、0.9,即nA/nB＜1)和A位过位(x=1.2,即nA/nB＞1)2种不同计量比情况,研究脉冲电流对上述3大类钙钛矿氧化物溶出行为的影响.利用XRD(X射线衍射仪)分析脉冲电流处理后的A位缺位钙钛矿(即x=0.8、0.9)时存在新的Co单质衍射峰;SEM(扫描电子显微镜)、TEM(透射电镜)观察发现,脉冲电流处理后A位缺位时有明显的Co纳米颗粒在表面溶出;电化学测试表明脉冲处理后的A位缺位钙钛矿氧化物x=0.9时,面积最大且CV(循环伏安)曲线更接近矩形,有着更优秀的可逆性能和良好的电荷传递能力.综合分析发现,当A位缺位时对于脉冲电流处理后的钙钛矿氧化物有助于形成氧空位,更有利于触发钙钛矿B位Co还原成金属纳米粒子溶出,提高电子传导性和催化活性.
Abstract
The perovskite oxide was successfully produced by applying PEC(pulsed electric current)treatment technique with(La0.7 Sr0.3)xTi0.93Co0.07O3 perovskite oxides as the substrate active material within 90 s under the pulsed parameter of 600 V-3 Hz.The ratio of A-site to B-site in ABO3(perovskite)under normal stoichiometry is nA/nB=1.Combined with two different stoichiometric ratio cases of A-site deficiency(x=0.8,x=0.9,nA/nB＜1)and A-site overdetermination(x=1.2,nA/nB＞1).XRD(X-ray diffractometer)was used to analyze the new Co singlet diffraction peaks in the A-site-deficient perovskite after pulse current treatment at x=0.8 and x=0.9.SEM(scanning electron microscope)and TEM(Transmission electron microscopy)observe that there are obvious Co nanoparticles dissolved on the surface in the A-site-deficient perovskite after pulse electric current treatment with a very homogeneous distribution.The electrochemical tests show that the oxidation peaks in the pulsed A-site-deficient perovskites at x=0.9 are very high,the area is the largest and the CV(cyclic voltamnetry)curve is closer to the rectangle,which has better reversibility and good charge transfer ability.The comprehensive analysis finds that,when the A-site is absent,the pulsed-current-treated chalcocite oxides are helpful to form the oxygen vacancies,which is more conducive to triggering the exsolution of chalcocite B-site Co reduction into metal nanoparticles exsolution,improving the electronic conductivity and catalytic activity.
关键词
脉冲电流/钙钛矿/纳米粒子/溶出Key words
pulsed electric current/perovskite/nanoparticle/exsolution引用本文复制引用
基金项目
国家自然科学基金(51354001)
辽宁省百千万人才工程项目(2018B014)
出版年
2024
国家科技期刊平台
NSTL
万方数据