High-performance BCN-C heterostructured electrocatalyst derived from covalent triazine frameworks for nitrogen reduction

Designing and synthesizing heterostructure-based catalysis combining two-dimensional (2D) materials has attracted enormous attention in materials chemistry, especially for electrocatalysis, due to their tunable electronic properties and structure. In this work, a boron carbon nitride (BCN)-coupled carbon (BCN-C) heterostructure with improved electronic performance was synthesized starting from C- and N-enriched 2D covalent triazine frameworks (CTFs) via a simple thermal transformation process using NaBH4 as the B source. The characterizations results showed that the B released from NaBH4 reacted with N and C in CTF, forming the BCN-C heterostructure coupling the BCN and carbon with a strong interfacial effect. The electrocatalytic NRR experiments and density functional theory (DFT) calculation revealed that the interfacial electronic properties and large numbers of active sites of the BCN-C heterostructure benefited the NRR. The BCN-C-1 catalyst showed a high Faradaic efficiency of 27.8% and an NH3 yield of 4.3 mu g h-1 mgcat.-1 in 0.1 M HCl electrolyte, owing to its high specific surface area (288 m2/g) with a large number of exposed active sites and the Mott-Schottky effect from the BCN-C heterostructure. This work highlights the design and synthesis of metal-free catalysts with high activity and selectivity and makes them excellent candidates for electrocatalytic applications.