Dai Zhengfei, Lee Chul-Soon, Kim Bo-Young, Kwak Chang-Hoon, Yoon Ji-Wook, Jeong Hyun-Mook, Lee Jong-Heun
Department of Materials Science and Engineering, Korea University , Seoul 136-713, Republic of Korea.
ACS Appl Mater Interfaces. 2014 Sep 24;6(18):16217-26. doi: 10.1021/am504386q. Epub 2014 Sep 9.
The use of composite materials and polynary compounds is a promising strategy to promote conductometric sensor performances. The perovskite oxides provide various compositional combinations between different oxides for tuning gas-sensing reaction and endowing rich oxygen deficiencies for preferable gas adsorption. Herein, a sacrificial colloidal template approach is exploited to fabricate crystalline ternary LaFeO3 perovskite porous thin films, by transferring a La(3+)-Fe(3+) hybrid solution-dipped template onto a substrate and sequent heat treatment. The honeycomb-like LaFeO3 film consisted of monolayer periodic pore (size: ∼ 500 nm) array can be successfully in situ synthesized in a homogeneous layout with a single phase of perovskite. This periodic porous LaFeO3 film with p-type semiconductivity exhibits a high gas response, fast response (∼4 s), trace detection capacity (50 ppb), and favorable ethanol selectivity from similar acetone. It exhibits enhanced sensing performances compared to those of a binary n-type Fe2O3 film and a nontemplated dense LaFeO3 film. In addition, a five-axe spiderweb diagram is introduced to make a feasible evaluation of the optimal practical work condition, comprehensively regarding the response/recovery rate, gas response, selectivity and operating temperature. The enhanced ethanol sensing mechanism of honeycomb-like LaFeO3 periodic porous film is also addressed. This novel and facile route to fabricate well-ordered porous LaFeO3 thin film can also be applied to many fields to obtain special performances, such as solar cells, ion conductors, gas separation, piezoelectricity, and self-powered sensing device system.
使用复合材料和多元化合物是提升电导传感器性能的一种很有前景的策略。钙钛矿氧化物在不同氧化物之间提供了多种组成组合，用于调节气敏反应并赋予丰富的氧缺陷以实现更好的气体吸附。在此，通过将浸渍有La(3+)-Fe(3+)混合溶液的模板转移到基板上并随后进行热处理，利用牺牲胶体模板法制备了结晶三元LaFeO3钙钛矿多孔薄膜。由单层周期性孔（尺寸：约500 nm）阵列组成的蜂窝状LaFeO3薄膜能够以钙钛矿单相的均匀布局成功原位合成。这种具有p型半导体性质的周期性多孔LaFeO3薄膜表现出高气体响应、快速响应（约4 s）、痕量检测能力（50 ppb）以及相对于类似丙酮的良好乙醇选择性。与二元n型Fe2O3薄膜和无模板致密LaFeO3薄膜相比，它展现出增强的传感性能。此外，引入了五轴蜘蛛网图，综合考虑响应/恢复率、气体响应、选择性和工作温度，对最佳实际工作条件进行可行的评估。还探讨了蜂窝状LaFeO3周期性多孔薄膜增强的乙醇传感机制。这种制备有序多孔LaFeO3薄膜的新颖且简便的方法也可应用于许多领域以获得特殊性能，如太阳能电池、离子导体、气体分离、压电性和自供电传感装置系统。
