Boosting faradaic reactions of metal oxides on polymeric carbon nitride/PANI hybrid

Polymeric carbon nitride (PCN) is considered a new emerging material for many potential energy applications. However, the abundant hydrogen bonds in the intralayer framework of PCN result in sluggish electron transport due to the high potential barrier for charge transfer. Here, we report that the exfoliated PCN featured with poor conductivity originated from abundant hydrogen bonds can be ameliorated by bridging with highly dispersible polyaniline (PANI) molecules in acidic media. Using this PCN/PANI hybrid as a promotor and substrate, vertically oriented growth of NiCo2O4 nanosheets can be successfully realized, allowing efficient permeation of electrolyte ions and providing more redox reaction sites. NiCo2O4 nanosheets grown on the PCN/PANI hybrid possess a specific capacity of 693C⋅g−1 at 1 A g−1, which is approximately 5 times improvement than that of pristine NiCo2O4. More specifically, the material retained 86.1% of its capacity after 10,000 cycles. An assembled asymmetric supercapacitor consisting of a composite electrode and commercially available activated carbon electrode can achieve a high energy density of 47.5 Wh⋅kg−1 at a power density of 375 W kg−1 (based on the weight of the two electrodes) with excellent cycling stability. These findings promote the development of highly efficient faradaic electrode materials based on PCN.