Preparation and photocatalytic activity analysis of nanometer TiO2 modified by surfactant

Wenzheng Wu,Xiaojie Zhai,Longjian Zhang,Ce Liang,Kaifeng Yu

doi:10.1177/1847980418781973

Abstract

Combining the advantages of the sol–gel method and solvothermal method, the single anatase phase of nano-titanium dioxide (TiO2) with high crystallinity had been prepared by means of the sol–solvent thermal improved process, in which butyl titanate was used as titanium source; anhydrous ethanol as solvent; concentrated nitric acid as inhibitor; and cationic surfactant cetyl trimethyl ammonium bromide (CTAB), anionic surfactant sodium dodecyl benzene sulfonate (SDBS), and nonionic surfactant polyethylene glycol (PEG) as dispersants. The analysis results of Brunauer–Emmett–Teller, scanning electron microscopy, and transmission electron microscopy characterizations indicated that CTAB-modified TiO2 with the optimum ratio had the most apparent dispersibility and the highest specific surface area compared with unmodified TiO2, SDBS-modified TiO2, and PEG-modified TiO2. At the same time, the photocatalytic degradation rate of methyl orange could be improved to 99.16%. It indicated that the modification effect of CTAB was significantly better than those of SDBS and PEG, which made the nanoparticles uniformly dispersed, resulting in higher photocatalytic activity.

Highlights

With the continuous improvement in people’s living standards, more and more products originate from nonrenewable natural sources such as petroleum, coal, and natural gas.[1,2,3] At the same time, the various steps of the extraction, transportation, and transformation of raw materials into final products are likely to bring negative effects to the environment.[4,5,6,7] The growth of global industry has greatly increased the generation and accumulation of waste byproducts, leading to double pressure from environmental pollution and energy shortages, that human beings are currently coping with.[8]
Under the optimum ratios of different types of surfactants, the photocatalytic degradation rates of cetyl trimethyl ammonium bromide (CTAB)-modified nanoTiO2, sodium dodecyl benzene sulfonate (SDBS)-modified nano-TiO2, and polyethylene glycol (PEG)-modified nanoTiO2 were improved by 16.28%, 13.41%, and 9.23% compared with unmodified nano-TiO2, respectively
In order to explore the optimization of the cationic surfactant CTAB, the anionic surfactant SDBS, and the nonionic surfactant PEG for nano-TiO2 modification, the TiO2 samples were taken for characterizations and photocatalytic performance tests according to the best dispersion ratios of 1:60, 1:30, and 1:30, respectively

Summary

Introduction

With the continuous improvement in people’s living standards, more and more products originate from nonrenewable natural sources such as petroleum, coal, and natural gas.[1,2,3] At the same time, the various steps of the extraction, transportation, and transformation of raw materials into final products are likely to bring negative effects to the environment.[4,5,6,7] The growth of global industry has greatly increased the generation and accumulation of waste byproducts, leading to double pressure from environmental pollution and energy shortages, that human beings are currently coping with.[8]. Under the optimum ratios of different types of surfactants, the photocatalytic degradation rates of cetyl trimethyl ammonium bromide (CTAB)-modified nanoTiO2, sodium dodecyl benzene sulfonate (SDBS)-modified nano-TiO2, and polyethylene glycol (PEG)-modified nanoTiO2 were improved by 16.28%, 13.41%, and 9.23% compared with unmodified nano-TiO2, respectively.

Results

Conclusion