CdS-Polydopamine-Derived N,S-Codoped Hierarchically Porous Carbons as Highly Active Electrocatalyst for Oxygen Reduction

Rational design of a highly active electrocatalyst for the oxygen reduction reaction (ORR) is critical for several advanced energy conversion and storage technologies such as fuel cells and rechargeable metal–air batteries. Engineering carbonaceous materials with heteroatoms can achieve optimal electronic and porous structures and show considerable electrocatalytic performance. In this work, a facile and highly efficient method for nitrogen and sulfur incorporation into a carbon skeleton has been developed based on CdS-polydopamine composites to derive the N,S-codoped hierarchical porous carbons. CdS plays an important role in the formation of this unique structure and the sulfur doping. Through pyrolyzing under inert atmosphere, the CdS-polydopamine can be easily transformed into N- and S-codoped porous carbons. The resultant N,S-codoped carbons possess hierarchically porous structures with high specific surface area, demonstrating superior ORR performance, which is higher than that of a commercial Pt/C catalyst in alkaline media in terms of onset potential, half-wave potential, and diffuse-limiting current density. The high ORR performance is also shown in both neutral and acidic media. In addition, the much higher stability and better methanol tolerance than Pt/C allow them to be a potential candidates for large-scale practical applications.