Microwave-Assisted Vacuum Synthesis of TiO2 Nanocrystalline Powders in One-Pot, One-Step Procedure.

Enrico Paradisi,Andrea Cioni,Roberto Rosa,Giada Lorenzi,Cristina Leonelli,Valentina Dami,Giovanni Baldi

doi:10.3390/nano12010149

Abstract

A new method for fast and simple synthesis of crystalline TiO2 nanoparticles with photocatalytic activity was developed by carrying out a classic sol–gel reaction directly under vacuum. The use of microwaves for fast heating of the reaction medium further reduces synthesis times. When the solvent is completely removed by vacuum, the product is obtained in the form of a powder that can be easily redispersed in water to yield a stable nanoparticle suspension, exhibiting a comparable photocatalytic activity with respect to a commercial product. The present methodology can, therefore, be considered a process intensification procedure for the production of nanotitania.

Highlights

The market demand for TiO2 nanopowders is continuously growing [1,2,3], due to the interesting properties of this material
We show that the vacuum sol–gel synthesis of TiO2 nanoparticles can be performed in a one-pot, one-step approach, and this can be an effective, fast, and reliable method to obtain crystalline nanoparticles with a good photocatalytic activity that, in principle, can be scaled up for large-scale production
dynamic light scattering (DLS) Results for Long-Term Aging In Table 2, the DLS results after 24 h of aging on the average nanoparticle size of the five batches produced are provided and compared with the corresponding industrial product

Summary

Introduction

The market demand for TiO2 nanopowders is continuously growing [1,2,3], due to the interesting properties of this material. Microwave (MW) heating technology can be classified as process intensification technology since its faster heating generally results in power and time-saving processes with respect to conventional heating [14,15,16]. For this reason, exploring MW heating and other methods for the fast synthesis of TiO2 nanoparticles can be valuable research for the chemical industry. The vacuum has been previously used in TiO2 treatments mainly in a second step carried out after its synthesis, in order, for example, to dry the material [19,20,21,22,23], anneal it [24,25], and impregnate selected substrates with this product [26,27,28], together with further post-synthetic

Methods

Results

Conclusion