Fabrication and interfacial electron transfer of ultrathin g-C_3N_4 nanosheet/TNT@CNTs ternary nanostructure heterojunction for high-efficiency visible-light-driven photocatalysis

摘要

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.