Photocatalysis by graphitic carbon nitride modified with 0D, 1D, and 2D carbon-based nanomaterials

Despite great interest in modifying graphitic carbon nitride (g-C₃N₄) with carbon-based nanomaterials (CBNs) towards photocatalysis, no study has systematically evaluated the efficacy of 0-2D CBNs. This work examined the photocatalysis of bisphenol A and tetracycline (BPA and TC) by g-C₃N₄ modified with 0D C₆₀, 1D single-walled and multi-walled carbon nanotubes (SWCNTs and MWCNTs), and 2D graphene oxide. Notably, the relative efficacy of g-C₃N₄/CBNs in photocatalysis can be readily tuned with CBN loading contents. g-C₃N₄ modified with SWCNTs (g-C₃N₄/SWCNT) usually exhibited superior photoreactivity with the only exception for 0.05% CBN loading where g-C₃N₄/MWCNT was the most photoactive. g-C₃N₄/C₆₀ showed the least photoreactivity. The photocatalyst's surface areas, light absorption, electrical resistance, and tendency of electron-hole recombination altogether can largely explain the observed photoreactivity. Superoxide was the primary radical responsible for the photocatalysis of BPA and TC. The result indicates that both CBN types and loading amounts are influential factors in the synthesis of highly reactive g-C₃N₄ modified with 0-2D CBNs, whose relative efficacy can be readily tuned with CBN loading.