2D Electron Gas and Oxygen Vacancy Induced High Oxygen Evolution Performances for Advanced Co 3 O 4 /CeO 2 Nanohybrids

作者：Ying Liu, Chao Ma, Qinghua Zhang, Wei Wang, Pengfei Pan, Lin Gu, Dongdong Xu, Jianchun Bao, Zhihui Dai · 发表于：Advanced Materials · 年份：2019 · DOI：10.1002/adma.201900062 · 被引用次数：329 · 研究领域：Electrocatalysts for Energy Conversion、Advanced Memory and Neural Computing、Catalytic Processes in Materials Science

Abstract The rational design of atomic‐scale interfaces in multiphase nanohybrids is an alluring and challenging approach to develop advanced electrocatalysts. Herein, through the selection of two different metal oxides with particular intrinsic features, advanced Co 3 O 4 /CeO 2 nanohybrids (NHs) with CeO 2 nanocubes anchored on Co 3 O 4 nanosheets are developed, which show not only high oxygen vacancy concentration but also remarkable 2D electron gas (2DEG) behavior with ≈0.79 ± 0.1 excess e − /u.c. on the Ce 3+ sites at the Co 3 O 4 –CeO 2 interface. Such a 2DEG transport channel leads to a high carrier density of 3.8 × 10 14 cm −2 and good conductivity. Consequently, the Co 3 O 4 /CeO 2 NHs demonstrate dramatically enhanced oxygen evolution reaction (OER) performances with a low overpotential of 270 mV at 10 mA cm −2 and a high turnover frequency of 0.25 s −1 when compared to those of pure Co 3 O 4 and CeO 2 counterparts, outperforming commercial IrO 2 and some recently reported representative OER catalysts. These results demonstrate the validity of tailoring the electrocatalytic properties of metal oxides by 2DEG engineering, offering a step forward in the design of advanced hybrid nanostructures.