TY - JOUR
T1 - Tuning the surface energy density of non-stoichiometric LaCoO3 perovskite for enhanced water oxidation
AU - Wang, Yuan
AU - Shen, Xiangjian
AU - Arandiyan, Hamidreza
AU - Yin, Yanting
AU - Sun, Fanfei
AU - Chen, Xianjue
AU - Garbrecht, Magnus
AU - Han, Li
AU - Andersson, Gunther G.
AU - Zhao, Chuan
PY - 2020/12/1
Y1 - 2020/12/1
N2 - Tailoring the surface structure of Earth-abundant perovskite oxides can provide cost-effective, high-efficient, and durable electrocatalysts for oxygen evolution reaction (OER). However, the structural origin leading to high OER performance of perovskite is not fully understood. Here, we present a strategy of tuning the surface energy density of non-stoichiometric perovskite by creating surface defects in the 3D inverse opal LaCoO3-x (3DIO-LaCoO3-x) through a colloidal template strategy. The defective 3DIO-LaCoO3-x, which has an enhanced surface energy density and a shift in the d-band centre of Co relative to the Fermi level, demonstrates significantly improved intrinsic OER activity, with a TOF (0.21 s−1) ten-folder larger than that of conventional LaCoO3 nanoparticles (0.02 s−1). The defective surfaces of 3DIO-LaCoO3-x are theoretically proven to alter the rate determining step of OER and significantly reduce the adsorption energies of the intermediate species, resulting in dramatically enhanced OER activity. Moreover, rich surface defects with high electrical conductivity can mitigate structural corrosion by fast transfer of charge through defective conductive channels, and thus enables long-term stability for the defective 3DIO-LaCoO3-x. These results provide an effective approach for enhancing the intrinsic activity of perovskite for water oxidation towards understanding the surface structure engineering for perovskite-based materials.
AB - Tailoring the surface structure of Earth-abundant perovskite oxides can provide cost-effective, high-efficient, and durable electrocatalysts for oxygen evolution reaction (OER). However, the structural origin leading to high OER performance of perovskite is not fully understood. Here, we present a strategy of tuning the surface energy density of non-stoichiometric perovskite by creating surface defects in the 3D inverse opal LaCoO3-x (3DIO-LaCoO3-x) through a colloidal template strategy. The defective 3DIO-LaCoO3-x, which has an enhanced surface energy density and a shift in the d-band centre of Co relative to the Fermi level, demonstrates significantly improved intrinsic OER activity, with a TOF (0.21 s−1) ten-folder larger than that of conventional LaCoO3 nanoparticles (0.02 s−1). The defective surfaces of 3DIO-LaCoO3-x are theoretically proven to alter the rate determining step of OER and significantly reduce the adsorption energies of the intermediate species, resulting in dramatically enhanced OER activity. Moreover, rich surface defects with high electrical conductivity can mitigate structural corrosion by fast transfer of charge through defective conductive channels, and thus enables long-term stability for the defective 3DIO-LaCoO3-x. These results provide an effective approach for enhancing the intrinsic activity of perovskite for water oxidation towards understanding the surface structure engineering for perovskite-based materials.
KW - Defects
KW - Electrocatalyst
KW - Oxygen evolution reaction
KW - Perovskite
KW - Surface energy density
UR - http://www.scopus.com/inward/record.url?scp=85090020344&partnerID=8YFLogxK
UR - http://purl.org/au-research/grants/ARC/FT170100224
UR - http://purl.org/au-research/grants/ARC/DE180100294
U2 - 10.1016/j.jpowsour.2020.228748
DO - 10.1016/j.jpowsour.2020.228748
M3 - Article
AN - SCOPUS:85090020344
SN - 0378-7753
VL - 478
JO - Journal of Power Sources
JF - Journal of Power Sources
M1 - 228748
ER -