Choi Min-Ju, Kim Taemin Ludvic, Kim Jeong Kyu, Lee Tae Hyung, Lee Sol A, Kim Changyeon, Hong Kootak, Bark Chung Wung, Ko Kyung-Tae, Jang Ho Won
Department of Materials Science and Engineering, Research Institute of Advanced Materials, Seoul National University, Seoul, 08826, Republic of Korea.
Max Planck POSTECH/Hsinchu Center for Complex Phase Materials and Department of Physics, Pohang University of Science and Technology, Pohang, 37673, Republic of Korea.
Nano Lett. 2020 Nov 11;20(11):8040-8045. doi: 10.1021/acs.nanolett.0c02949. Epub 2020 Nov 2.
As the BO octahedral structure in perovskite oxide is strongly linked with electronic behavior, it is actively studied for various fields such as metal-insulator transition, superconductivity, and so on. However, the research about the relationship between water-splitting activity and BO structure is largely lacking. Here, we report the oxygen evolution reaction (OER) of LaNiO (LNO) by changing the NiO structure using compositional change and strain. The 5 atom % La deficiency in LNO resulted in an increase of the Ni-O-Ni bond angle and an expansion of bandwidth, enhancing the charge transfer ability. In-plane compressive strain derives the higher d orbital occupancy, leading to suitable metal-oxygen bond strength for OER. Because of the synergistic effect of A-site deficiency and compressive strain, the overpotential (η) of compressively strained LNO film is reduced to 130 mV at = 30 μA/cm compared with nonstrained LNO (η = 280 mV), indicating a significant enhancement in OER.
由于钙钛矿氧化物中的BO八面体结构与电子行为密切相关，因此在金属-绝缘体转变、超导等各个领域都对其进行了积极研究。然而，关于析氢活性与BO结构之间关系的研究却非常匮乏。在此，我们通过成分变化和应变来改变NiO结构，报道了LaNiO（LNO）的析氧反应（OER）。LNO中5原子%的La缺陷导致Ni-O-Ni键角增大和带宽扩展，增强了电荷转移能力。面内压缩应变导致更高的d轨道占有率，从而产生适合OER的金属-氧键强度。由于A位缺陷和压缩应变的协同作用，与未应变的LNO（η = 280 mV）相比，压缩应变LNO薄膜在 = 30 μA/cm时的过电位（η）降低至130 mV，表明OER有显著增强。
Zotero 插件