Chauhan Manisha, Jha Pardeep K, Bangwal Ajay S, Jha Priyanka A, Singh Prabhakar
Department of Physics, Indian Institute of Technology (Banaras Hindu University) Varanasi, Varansi-221005, India.
Phys Chem Chem Phys. 2020 Jun 4;22(21):12294-12300. doi: 10.1039/d0cp00433b.
Rare earth nickelate perovskites have very wide uses, as magnetic insulators, as well as being conducting materials for the various components of solid oxide fuel cells (SOFCs) due to them undergoing an insulator to metal transition below operating temperature. In SOFCs, the microstructural design of electrode materials is an important aspect for electron and oxygen ion conduction at the electrolyte-electrode and electrode-air interfaces. To investigate this feature, a Ruddlesen-Popper structured layered perovskite, (SmSr)NiO4-δ, was synthesized at different sintering temperatures using a solid-state reaction technique. Porous and dense microstructures were obtained at sintering temperatures of 1250 and 1425 °C, respectively. The influence of electrocatalysis on the structures of both surfaces was studied comprehensively. Post cyclic voltammetry structural studies show the presence of Ni-(OH)2 and Ni-OOH species for the samples, respectively, suggesting that they undergo different oxygen reduction reaction mechanisms.
稀土镍酸盐钙钛矿用途广泛，可作为磁绝缘体，还由于在低于工作温度时会发生绝缘体到金属的转变，因而可作为固体氧化物燃料电池（SOFC）各部件的导电材料。在SOFC中，电极材料的微观结构设计是在电解质 - 电极和电极 - 空气界面实现电子和氧离子传导的一个重要方面。为了研究这一特性，采用固态反应技术在不同烧结温度下合成了一种Ruddlesen - Popper结构的层状钙钛矿（SmSr）NiO4-δ。分别在1250和1425℃的烧结温度下获得了多孔和致密的微观结构。全面研究了电催化对两个表面结构的影响。循环伏安法后的结构研究表明，样品分别存在Ni-(OH)2和Ni - OOH物种，这表明它们经历了不同的氧还原反应机制。
