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.