ZnO Polymeric Composite Films for n-Decane Removal from Air Streams in a Continuous Flow NETmix Photoreactor under UVA Light.

Crissie D Zanrosso,Marla A Lansarin,Vítor J P Vilar,Sandra M Miranda,Batuira M Da Costa Filho,Jonathan C Espíndola,Diego Piazza

doi:10.3390/nano11081983

Abstract

Polymeric composite films have been explored for many photocatalytic applications, from water treatment to self-cleaning devices. Their properties, namely, thickness and porosity, are controlled mainly by the preparation conditions. However, little has been discussed on the effect of thickness and porosity of polymeric composite films for photocatalytic processes, especially in gas phase. In the present study, different preparation treatments of ZnO-based polymeric composite films and their effects on its performance and stability were investigated. The polymeric composites were prepared by solution mixing followed by non-solvent induced phase separation (NIPS), using poly(vinylidene fluoride) (PVDF) as the matrix and ZnO-based photocatalysts. Different wet thickness, photocatalyst mass, and treatments (e.g., using or not pore-forming agent and compatibilizer) were assessed. A low ZnO/PVDF ratio and higher wet thickness, together with the use of pore-forming agent and compatibilizer, proved to be a good strategy for increasing photocatalytic efficiency given the low agglomerate formation and high polymer transmittance. Nonetheless, the composites exhibited deactivation after several minutes of exposure. Characterization by XRD, FTIR-ATR, and SEM were carried out to further investigate the polymeric film treatments and stability. ZnO film was most likely deactivated due to zinc carbonate formation intensified by the polymer presence.

Highlights

Photocatalysis, a highly efficient, economic, and environmental-friendly technology, is an interesting approach for environmental remediation purposes as it offers a remarkable potential for pollutants oxidation/reduction and, environmental protection [1]
The composite films stability in terms of photocatalytic activity was firstly evaluated for three different types of polymeric composite films at the same photocatalyst:polymer ratio (0.50:2.25). n-Decane photocatalytic oxidation (PCO) tests were performed in continuous mode for 5 h
The preparation strategy of ZnO-based polymeric composite films was evaluated for a VOC removal in continuous flow, simulated in extreme conditions of VOC

Summary

Introduction

Photocatalysis, a highly efficient, economic, and environmental-friendly technology, is an interesting approach for environmental remediation purposes as it offers a remarkable potential for pollutants oxidation/reduction and, environmental protection [1]. Research has mainly been focused on the development of advanced photocatalytic materials and their immobilization in inert supports or its incorporation in substrates (composite materials), towards a substantially higher photocatalytic activity and avoiding post-treatment steps, respectively [2,3]. Thin films can be defined as a layer that extends along with any two directions and is restricted along the third direction, having a small thickness (from nanometers to a few micrometers). This dimension is the main advantage of thin-film technology, providing cost reduction and miniaturization of devices [5]. The properties of the films are mainly controlled by the film structure, reaction condition, and treatment method [6]

Objectives

Methods

Results

Conclusion