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.

The iChEM researcher, Prof. Gengfeng Zheng from the Department of Chemistry and Advanced Materials Laboratory of FDU developed 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. Their result was published on Journal of American Chemical Society in the title of“Nanoparticle superlattices as efficient bifunctional electrocatalyst for water splitting” (J. Am. Chem. Soc., DOI: 10.1021/jacs.5b07756).



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%. Their 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.

Paper link：http://pubs.acs.org/doi/abs/10.1021/jacs.5b07756