Enhanced photocatalytic degradation of organic compounds on multiwalled carbon nanotube/TiO2 composites

摘要

This paper examined the efficacy with which the multiwalled carbon nanotube (MWCNT)/TiO2 composites reduced charge recombination and enhanced reactivity.A visible-light photocatalyst of MWCNT/TiO2 was synthesized by a two-step method,in which TiO2 was first mounted on MWCNT surface by hydrolysis of tetrabutyl titanate and further crystallized into anatase nanocrystal in a vacuum furnace at 500 ℃.The photocatalytic degradation of organic compounds over the UV and visible-light spectrum regions was investigated.The MWCNT/TiO2 composites were able to absorb a high amount of photo energy in the visible-light region,driving effectively photochemical degradation reactions.There were more ·OH radicals produced by the MWCNT/TiO2 (1∶3) than by pure TiO2 under UV and visible-light irradiation.In the photodegradation of methylene blue,as a model reaction,a signification enhancement in the reaction rate was observed with the MWCNT/TiO2 composite (1∶3),compared to bare TiO2 and the physical mixture of MWCNTs and TiO2.MWCNTs can enhance the photocatalytic activity of TiO2 in two aspects,namely,e(-) transportation and adsorption.This work provides new insight into the fabrication of MWCNT/TiO2 as a high performance visible-light photocatalyst and facilitates its application in photocatalytic degradation of organic compounds.