Porous Hybrid Nanosheets of g-C3N4/β-Ni(OH)2 for Asymmetric Supercapacitor with Enhanced Specific Capacitance

Porous hybrid nanosheets of g-C 3 N 4 /[Formula: see text]-Ni(OH) 2 (CN/[Formula: see text]-NiOH) were constructed via gas bubble method in the NiCl[Formula: see text]H 2 O-NH 3 [Formula: see text][Formula: see text][Formula: see text]H 2 O-C 2 H 5 OH-CN system at 140 ∘ C for 6[Formula: see text]h. The resulting CN(5.3[Formula: see text]wt.%)/[Formula: see text]-NiOH nanosheets show a porous texture and a large interface contact area, which facilitates the electrolyte ion diffusion during reversible insertion/deinsertion processes. The fabricated CN(5.3[Formula: see text]wt.%)/[Formula: see text]-NiOH hybrid-based electrode displays an enhanced specific capacitance of 887[Formula: see text]F[Formula: see text]g[Formula: see text] at a current density of 0.5[Formula: see text]A[Formula: see text]g[Formula: see text] when compared with single phase [Formula: see text]-NiOH (480[Formula: see text]F[Formula: see text]g[Formula: see text]). Using CN(5.3[Formula: see text]wt.%)/[Formula: see text]-NiOH porous nanosheets and activated carbon (AC) as cathode and anode, an asymmetric supercapacitor (ASC) was assembled and the energy density achieves 28.3[Formula: see text]Wh[Formula: see text]kg[Formula: see text] and 10.9[Formula: see text]Wh[Formula: see text]kg[Formula: see text] at a power density of 798.4[Formula: see text]W[Formula: see text]kg[Formula: see text] and 7991.9[Formula: see text]W[Formula: see text]kg[Formula: see text], respectively.