Textural properties dependent supercapacitive performances of mesoporous graphitic carbon nitride

Abstract

In this article, the tunable capacitance properties of mesoporous graphitic carbon nitride (MGCN) by tailoring its textural properties are reported. MGCN with different textural properties is synthesized by a hard template method using two different templates namely, SBA-15 and KIT-6. The formation of graphitic layers in the as-synthesized samples is confirmed by X-ray diffraction studies and successful replication of morphology and mesoporosity of the templates into the as-synthesized samples is confirmed by microscopic and nitrogen adsorption-desorption studies. The bulk and surface chemical composition of the as-synthesized samples are analyzed using Fourier transform infrared spectroscopy, CHNS/O analysis and X-ray photoelectron spectroscopic studies. The specific capacitance values of 322 and 245 F g−1 are obtained at a current density of 0.5 A g−1 for MGCN synthesized using SBA-15 and KIT-6, respectively. Although, MGCN synthesized using SBA-15 (MGCN-SBA-15) exhibits higher specific capacitance than MGCN synthesized using KIT-6 (MGCN-KIT-6), its rate performance is slightly lower than that of MGCN-KIT-6. The higher specific capacitance of MGCN-SBA-15 is attributed to its high surface area, more number of mesopores and large pore volume, whereas the presence of highly ordered mesopores in MGCN-KIT-6 results in higher rate performance. Both MGCN-SBA-15 and MGCN-KIT-6 electrodes demonstrate excellent cycling stability over 15,000 cycles. These results demonstrate that the supercapacitive performances of MGCN can be improved by tailoring its textural properties.