Preparation of Titania on Stainless Steel by the Spray-ILGAR Technique as Active Photocatalyst under UV Light Irradiation for the Decomposition of Acetaldehyde

Hadi Nur,Bunsho Ohtani,Kamarulafizam Ismail,Sheela Chandren

doi:10.3390/app7070698

Abstract

One of the methods used to produce buffer layers for thin film solar cells is the Spray ion layer gas reaction (SPRAY-ILGAR). This method has exhibited astonishing efficiencies in the fabrication of homogenous compact metal chalcogenide films. The same approach can be applied in the preparation of photocatalyst on a substrate, in order to acquire a homogeneous and durable layer. In this work, the Spray-ILGAR technique has been utilized in the preparation of titania photocatalysts on stainless steel, which was carried out at Helmholtz-Zentrum Berlin for Materials and Energy, in Berlin, Germany. The characterizations and photocatalytic testing of the synthesized materials were then done at the Institute of Catalysis, Hokkaido University. The scanning electron microscopy (SEM) analysis showed that the titania was dispersed uniformly on top of the stainless steel, with a very durable and strong attachment. It was also found that the concentration of the titania on stainless steel can be easily varied by changing the concentration of the titania-precursor solution. Higher concentrations will result in a more compact and dense layer, while lowering the concentration of the precursor solution produces a less dense layer of TiO2. Apart from that, different temperatures did not change the distribution of the samples much. The photocatalytic activity of the synthesized materials was determined in terms of the photocatalytic decomposition of acetaldehyde under ultra violet (UV) light irradiation. The photocatalytic testing results proved that the samples can completely degrade acetaldehyde under UV irradiation. The heating temperature played a crucial role, as the sample prepared by with heating temperature of 550 °C, concentration of titania-precursor of 6.83 mM and a spraying time of 12 min showed the best results, requiring only 35 min to fully degrade 500 ppm of acetaldehyde.

Highlights

Global environmental pollution and destruction are issues of increasing concern in today’s society, necessitating effective catalysts to degrade harmful pollutants
For titania prepared on stainless steel using the Spray-ion layer gas reaction (ILGAR) technique, the standard procedure is to use titania (TiO2 ) precursor of titanium diisopropoxide bis(acetylacetone) in ethanol with a concentration of 6.83 mM, sprayed for 12 min at a temperature of 460 ◦ C
In order to determine the best condition to prepare a sample with the best photocatalytic activity in the photocatalytic decomposition of air pollutants, the TiO2 on stainless steel was prepared with different concentrations of TiO2 -precursor, different heating temperatures, and different durations of spraying time

Summary

Introduction

Global environmental pollution and destruction are issues of increasing concern in today’s society, necessitating effective catalysts to degrade harmful pollutants. Sci. 2017, 7, 698 semiconductors has garnered widespread interest, as a means to induce and improve photocatalytic reactions. A prime example would be metal oxide semiconductor powders, which have exhibited activity when irradiated with ultraviolet (UV) light, and have been widely used as photocatalysts for the degradation of pollutants [1,2]. Titania (TiO2 ) has been widely used as a catalyst, due to its many advantageous qualities, namely optical and electronic properties, low cost, high level of photocatalytic activity, chemical stability and non-toxicity [3,4,5]

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Results

Conclusion