Enhanced supercapacitive performance of graphite-like C3N4 assembled with NiAl-layered double hydroxide

A hybrid g-C3N4/NiAl-layered double hydroxide (LDH) nanocomposite for supercapacitor has been prepared via in situ growth of NiAl-LDH nanoflakes on graphite-like C3N4 nanosheets. SEM, TEM, XRD, XPS, and FT-IR were utilized to characterize the as-prepared nanocomposite. Interestingly, many intercrossed ultrathin LDH nanoflakes were found growing perpendicularly on the surface of g-C3N4 while LDH nanoparticles with size of 5 nm were dispersed right on the edge of g-C3N4. Due to this unique morphology and structure, BET surface area of these nanocomposites have been increased tremendously and the mesopore size distribution has been optimized as well. Electrochemical properties of these nanocomposites were further evaluated by using cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy (EIS), respectively. The results showed that these g-C3N4/NiAl-LDH nanocomposites exhibited a maximum specific capacitance of 714 F g−1 at current density of 0.5 A g−1 and remained at 354 F g−1 when the current density was increased to 10 A g−1. Meanwhile, the capacitance could be kept 82% even after 10000 cycles at 10 A g−1, which indicated that the as-prepared nanocomposite possessed promising high-current capacitive properties. Furthermore, ion transporting resistance of the as-prepared nanocomposite was reduced due to the presence of g-C3N4 nanosheets. All the results demonstrated that the g-C3N4/NiAl-LDH nanocomposite had a great potential to be used as novel nanomaterials for supercapacitor electrodes.