Tuning the chemical composition, textural and capacitance properties of mesoporous graphitic carbon nitride

The interactions between the surfactants and the precursors play significant roles in tuning the textural properties of mesoporous graphitic carbon nitride (MGCN), whereas the degree of polycondensation of the precursors is influenced by the nature of the surfactant employed, which in turn affect the C/N ratio and surface functionalities of MGCN. Herein, we report the effect of surfactants, namely; cationic (cetyl trimethylammonium bromide, CTAB), neutral (polyethylene glycol p-(1,1,3,3-tetramethylbutyl)-phenyl ether, Triton X-100) and anionic (sodium dodecyl sulfate, SDS) on the C/N ratio, functionalities, textural properties and the capacitance performance of MGCN. The formation of MGCN with different textural properties is confirmed by the microscopic and sorption studies. The variation in the C/N ratio and surface functionalities of the MGCN samples are investigated by elemental analysis, X-ray photoelectron spectroscopic and Fourier transform infrared spectroscopic studies. Among all MGCN samples, the highest specific capacitance of 279 F g(-1) at a current density of 0.5 A g(-1) is obtained for MGCN synthesized using Triton X-100 (MGCN-T). It also exhibits better rate performance than the other two samples. This superior capacitance performance of MGCN-T is attributed to higher surface area, more number of mesopores, larger pore volume, higher number of graphitic carbon domains and surface functionalities. A symmetrical supercapacitor device fabricated using MGCN-T delivers energy density of 20.97Wh kg(-1) at a power density of 499.94Wkg(-1), which is higher than the values reported for various nitrogen-doped carbonaceous materials. Further, the device exhibits stable cycling over 10,000 cycles. (c) 2019 Elsevier Ltd. All rights reserved.