Nanoparticle Superlattices as Efficient Bifunctional Electrocatalysts for Water Splitting.
The solar-driven water splitting process is highly attractive for alternative energy utilization, while developing efficient, earth-abundant, bifunctional catalysts for both oxygen evolution reaction and hydrogen evolution reaction has remained as a major challenge. Herein, we develop an ordered CoMnO@CN superlattice structure as an efficient bifunctional water-splitting electrocatalyst, in which uniform Co-Mn oxide (CoMnO) nanoparticles are coated with a thin, continuous nitrogen-doped carbon (CN) framework. The CoMnO nanoparticles enable optimized OER activity with effective electronic structure configuration, and the CN framework serves as an excellent HER catalyst. Importantly, the ordered superlattice structure is beneficial for enhanced reactive sites, efficient charge transfer, and structural stability. This bifunctional superlattice catalyst manifests optimized current densities and electrochemical stability in overall water splitting, outperforming most of the previously reported single- or bifunctional electrocatalysts. Combining with a silicon photovoltaic cell, this CoMnO@CN superlattice bifunctional catalyst enables unassisted solar water splitting continuously for ∼5 days with a solar-to-hydrogen conversion efficiency of ∼8.0%. Our discovery suggests that these transition metal oxide-based superlattices may serve as a unique structure modality for efficient bifunctional water splitting electrocatalysts with scale-up potentials.
Jun
J
Li
Yongcheng
Y
Wang
Tong
T
Zhou
Soochow University-Western University Centre for Synchrotron Radiation Research, Institute of Functional Nano and Soft Materials Laboratory, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
Hui
H
Zhang
Soochow University-Western University Centre for Synchrotron Radiation Research, Institute of Functional Nano and Soft Materials Laboratory, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University , Suzhou, Jiangsu 215123, China.
Xuhui
X
Sun
Jing
J
Tang
Lijuan
L
Zhang
Department of Chemistry, College of Science, King Saud University , Riyadh 11451, Saudi Arabia.
Abdullah M
AM
Al-Enizi
Zhongqin
Z
Yang
Gengfeng
G
Zheng