Controllable growth of graphdiyne layered nanosheets for high-performance water oxidation

Abstract

Developing highly active, stable and low-cost electrocatalysts capable of an efficient oxygen evolution reaction (OER) is urgent and challenging. Here we report a facile and general strategy for synthesizing a noble-metal-free electrocatalyst consisting of graphdiyne (GDY)-encapsulated cerium/nickel layered double-hydroxide nanosheets (CeNiLDH@GDY) with a remarkable OER performance. Experimental results demonstrate that the remarkable synergistic effects among different components in the catalyst confer to the catalyst great advantages for combining activity and stability towards an excellent OER performance. The optimal electrocatalyst (Ce_0.6Ni_0.4LDH@GDY) shows excellent OER performances with a small overpotential of 283 mV to reach 10 mA cm⁻² and a high long-term stability over 60 h at around 15 mA cm⁻² with almost no decrease in current density. Our results show that the in situ growth of graphdiyne on the LDH surface can form an ideal interface structure leading to an increase in the active surface area and the number of active sites, promoting the charge transfer behavior, protecting the catalyst from corrosion, and consequently enhancing the catalytic performances. This work provides a general method for the design and fabrication of highly active and stable electrocatalysts with desired active site structures for water splitting.