Ni₂P₂O₇Nanoarrays with Decorated C₃N₄Nanosheets as Efficient Electrode for Supercapacitors

Ni2P2O7-based composites grown on conductive substrate can efficiently promote the electrical transport during the electrochemical reactions in supercapacitors. However, Ni2P2O7 nanoarrays are easily peeled off from the substrate upon repeated electrochemical reaction. Herein, Ni2P2O7 nanoarrays grown on Ni foam with surficially decorated C3N4 thin nanosheets are achieved by a hydrothermal and in situ calcination strategy. The decorated C3N4 nanosheet network on the surface fully covers both Ni2P2O7 and Ni foam and efficiently prevents Ni2P2O7 nanoarrays from peeling off during the charge and discharge cycles. The optimized composites exhibit high pseudocapacitance and greatly enhanced cycling stability. The assembled asymmetric supercapacitor shows favorable specific capacitance and stability as energy storage devices. Such a strategy for fabricating C3N4-modified Ni2P2O7 nanoarrays is feasible and efficient, and can be therefore extended for constructing other electrodes with high capacitance and excellent stability.