Synthesis of mesoporous niobium nitride nanobelt arrays and their capacitive properties

Abstract Mesoporous niobium nitride nanobelt arrays (Nb 4 N 5 NBAs) are fabricated directly on Nb foils by a hydrothermal reaction in KOH, protonation treatment in HNO 3 , and calcination in an NH 3 ambient. The morphology, composition and pore structure of the Nb 4 N 5 NBAs are characterized in details. In addition, the mesoporous Nb 4 N 5 NBAs electrode has good specific capacitance (37.4 mF cm −2 , or 124 F g −1 ) and delivers excellent rate performance due to the high porosity and good electron conductivity boding well for application to next-generation energy storage systems.