In-situ N-doping triggers co − N interface reconstruction for enhanced Pseudocapacitive performance of NiCo-BTC

Bimetallic organic frameworks have attracted substantial interest in the supercapacitor domain owing to their extensive specific surface areas and rich porosity. Nevertheless, their practical performance is constrained by inadequate active surface areas and the limited exposure of active sites. Here, NiCo-BTC-0.5 N was prepared via an in situ solvothermal approach with cyanoguanidine introduced as the nitrogen source, which promoted a high density of Co N bonds and induced substantial interfacial reconstruction. This modified structure contributed to enriching electrochemical active surface area compared to the unmodified NiCo-BTC. Electrochemical tests showed that NiCo-BTC-0.5 N exhibits a specific capacitance of 1840.97 F g −1 when tested at 1 A g −1 . It maintains 75.15 % of its rate performance at 20 A g −1 , demonstrating excellent rate performance, and exhibits 95.90 % cycling stability after 5500 charge-discharge cycles. Furthermore, when integrated with an activated carbon anode, it delivers an energy density of 42.13 Wh kg −1 at a power density of 860 W kg −1 . This result shows that doping-induced interfacial reconstruction can significantly enhance material performance and provides a compelling strategy for surface engineering in the development of supercapacitors with enhanced capabilities.