![Sample our Environment & Sustainability journals, sign in here to start your access, latest two full volumes FREE to you for 14 days]({"type":"image" , "src" : "/sda/5935/TOC-Subject-Sample-2021-Environment-Sustainability.jpg"})
Abstract
Electron–hole recombination is the most important factor limiting the efficiency of TiO2-based photocatalysts. In this work, multi-walled carbon nanotube (MWCNT) was used to suppress the electron–hole recombination and enhance the photocatalytic efficiency of titanium dioxide (TiO2) nanoparticles. Primarily, nanocomposite of MWCNT/TiO2 as a hybrid photocatalyst with different weight ratio of TiO2 and MWCNT (from 0.95:0.05 to 0.75:0.25) was produced and characterized. The composites were characterized by a series of analytical techniques including SEM, TEM, XRD, and UV–vis to reveal the textural, crystallographic, and optical properties of the composites. These techniques indicated a uniform, mesoporous, and well-defined nanometer scale anatase titania (TiO2) layer on individual MWCNT. Secondly, significantly enhanced photocatalytic activity of TiO2 was systematically studied by introducing MWCNT in the photocatalytic oxidation and mineralization of petroleum refinery wastewater (PRW) in a batch circulating photocatalytic reactor. The results showed that when the proportion ratio of TiO2 and MWCNT reached 0.8:0.2, the synthesized MWCNT/TiO2 nanocomposite demonstrated the maximum photocatalytic efficiency on PRW treatment. The increase in the removal efficiency with increase in MWCNT/TiO2 ratio was due to great capability of MWCNT in the adsorption of organic molecules and charge separation.