Facile synthesis of graphitic C 3 N 4 nanoporous-tube with high enhancement of visible-light photocatalytic activity

Abstract A simple and convenient method was used to synthesize a graphitic carbon nitride (g-C 3 N 4 ) nanoporous-tube by using SiO 2 nanoparticles as pore formers. The structure of the g-C 3 N 4 nanoporous-tube was characterized by the SEM and TEM images. Taking photodegradation of RhB as an example, the photocatalytic activity of the as-prepared g-C 3 N 4 nanoporous-tube was investigated. It can photodegrade 90% RhB in 40 min under visible-light irradiation and obtain a k value of 0.04491 min −1 , which is 8.16 times that of bulk g-C 3 N 4 , 3.09 times that of tubular g-C 3 N 4 and 1.48 times that of tubular g-C 3 N 4 -SiO 2 . The significant enhancement in photocatalytic efficiency is due to the edge effect of the pores and the special structure of the tubes. In addition, the possible mechanism of photocatalytic degradation of RhB was also proposed based on the trapping experiment of active species, which indicated that the superoxide radicals ( O 2 • − ) and the holes ( h + ) were the main reactive species in this photocatalyst. This work may open up a new idea of innovation in g-C 3 N 4 structure and inspire its follow-up study.