Fabrication and interfacial electron transfer of ultrathin g-C3N4 nanosheet/TNT@CNTs ternary nanostructure heterojunction for high-efficiency visible-light-driven photocatalysis

The purpose of this research is to design and fabricate a novel ternary hybrid nanostructure heterojunction with high-efficiency visible-light-driven photocatalysis. The porous layered TiO 2 nanotubular structures (TNTs) with high percentage of photocatalytic reactive facets, which were turned into by commercially available TiO 2 , were wrapped on the surface of hydroxylation carbon nanotubes (CNTs) through the formation of Ti–O=C and/or Ti–O–C bond between CNTs and TiO 2 . Then the TNT@CNT nanotubular composites were coated by ultrathin g-C 3 N 4 nanosheets with a thickness of 3–4 nm. The ternary nanocomposites owned strong absorption performance, low charge recombination rates and high-efficiency photocatalytic activities, which were all owe to high surface areas and excellent adsorptivity of the CNTs, photocatalytic performance of TiO 2 nanotubes (TNTs) and moderate band gap of g-C 3 N 4 nanosheet. What’s more, the formation of chemical bonds greatly improved visible-light photocatalytic activity with a degradation rate of 98.2 and 97.9% for methylene blue and rhodamine B in 60 min under visible-light irradiation, which showed ~ 10 times enhancement compared to pure TiO 2 . In addition, the existence of h + and ·OH and ·O 2− radicals played main role in the photocatalytic process. The new material was of great significance to environmental protection and energy criss.