Facile synthesis and electrochemical properties of nanoflake VN for supercapacitors

Vanadium nitrides (VN) have drawn much attention due to their large negative potential window, high electronic conductivity and fast reversible redox reaction. The electrochemical performances of VN are affected by their morphology and specific surface area, which depend deeply on the synthesis method. Herein, a large-sized nanoflake V 2 O 5 xerogel is synthesized by a hydrothermal method followed by freeze drying, and then the nanoflake V 2 O 5 xerogel is thermally treated for various times under NH 3 atmosphere to study the nitriding process. The results show that the nanoflake V 2 O 5 xerogel is reduced to nanoflake V 2 O 3 before being completely transformed into nanoflake VN. The nanoflake VN demonstrate superior capacitive performance than the nanoflake V 2 O 5 xerogel and intermediate V 2 O 3 , which arises from higher intrinsic conductivity. Large-sized VN nanoflakes are synthesized through ammoniating the V 2 O 5 precursor at a mild condition. The nitriding process and electrochemical performance of VN are studied.