title: Synthesis and application of hexagonal perovskite BaNiO3 with quadrivalent nickel under atmospheric and low-temperature conditions.
abstract: A hexagonal perovskite BaNiO3 with unusually high-valence nickel(iv) was synthesized under atmospheric and low-temperature conditions by an ethylenediamine-derived wet-chemical route. Secondary phases disappeared with increase in the pH value, and the single-phase BaNiO3 was successfully synthesized at pH 10. The specific surface area was ∼32 m(2) g(-1), which is significantly enhanced compared to the BaNiO3 (0.3 m(2) g(-1)) synthesized by flux-mediated crystal growth. The BaNiO3 was used as an oxygen-evolution reaction (OER) catalyst, and the specific mass activity was ∼5 times higher than that of the BaNiO3 synthesized by flux-mediated crystal growth. As a result, the ethylenediamine-derived sol-gel synthesis could be a simple technique to prepare crystalline compounds such as perovskites and spinels, with unusually high-valence transition metals.
authors.affiliation: Department of Chemical and Bio-molecular Engineering, Yonsei University, 134 Shinchon-dong, Seodaemun-gu, Seoul, 120-749, Republic of Korea. shulyg@yonsei.ac.kr.
authors.forename: Jin Goo
authors.initials: JG
authors.lastname: Lee
authors.forename: Ho Jung
authors.initials: HJ
authors.lastname: Hwang
authors.forename: Ohchan
authors.initials: O
authors.lastname: Kwon
authors.forename: Ok Sung
authors.initials: OS
authors.lastname: Jeon
authors.forename: Jeongseok
authors.initials: J
authors.lastname: Jang
authors.forename: Yong-Gun
authors.initials: YG
authors.lastname: Shul