Multifunctional g-C₃N₄ nanofibers: A template-free fabrication and enhanced optical, electrochemical, and photocatalyst properties

We have developed a facile, scale up, and efficient method for the preparation of graphitic-C₃N₄ nanofibers (GCNNFs) as electrodes for supercapacitors and photocatalysts. The as-synthesized GCNNFs have 1D structure with higher concentration of nitrogen that is favorable for higher conductivity and electrochemical performance. Secondly, the high surface area of GCNNF provides a large electrode-electrolyte contact area, sufficient light harvesting and mass transfer, as well as increased redox potential. Thus, the GCNNF supercapacitor electrode shows high capacitance of 263.75 F g ^-1 and excellent cyclic stability in 0.1 M Na₂SO ₄ aqueous electrolyte with the capacitance retention of 93.6% after 2000 cycles at 1 A g^-1 current density. GCNNFs exhibit high capacitance of 208 F g^-1 even at 10 A g^-1, with the appreciable capacitance retention of 89.5%, which proves its better rate capability. Moreover, the GCNNF shows enhanced photocatalytic activity in the photodegradation of RhB in comparison to the bulk graphitic-C₃N ₄ (GCN). The degradation rate constant of GCNNF photocatalyst is almost 4 times higher than GCN. The enhanced photocatalytic activity of GCNNF is mainly due to the higher surface area, appropriate bandgap, and fewer defects in GCNNF as compared to GCN. As an economical precursor (melamine) and harmless, facile, and template-free synthesis method with excellent performance both in supercapacitors and in photodegradation, GCNNF is a strong candidate for energy storage and environment protection applications.