Removal of Indoor Volatile Organic Compounds via Photocatalytic Oxidation: A Short Review and Prospect

Abstract

Volatile organic compounds (VOCs) are ubiquitous in indoor environments. Inhalation of VOCs can cause irritation, difficulty breathing, and nausea, and damage the central nervous system as well as other organs. Formaldehyde is a particularly important VOC as it is even a carcinogen. Removal of VOCs is thus critical to control indoor air quality (IAQ). Photocatalytic oxidation has demonstrated feasibility to remove toxic VOCs and formaldehyde from indoor environments. The technique is highly-chemical stable, inexpensive, non-toxic, and capable of removing a wide variety of organics under light irradiation. In this paper, we review and summarize the traditional air cleaning methods and current photocatalytic oxidation approaches in both of VOCs and formaldehyde degradation in indoor environments. Influencing factors such as temperature, relative humidity, deactivation and reactivations of the photocatalyst are discussed. Aspects of the application of the photocatalytic technique to improve the IAQ are suggested.

ZnO for photocatalytic air purification applications

“…The photocatalytic materials have various applications such as self-cleaning [1], antifogging [2], antibacterial actions [3][4][5], deodorization [6] or decomposition and removal of pollutant [7][8][9][10][11][12][13]. These applications are responsible for the development of a broaden range of so called smart materials used constructions.…”

Preparation and analysis of zero gases for the measurement of trace VOCs in air monitoring

“…Titanium dioxide (TiO 2 ) is the dominant photo-catalyst because of its excellent photocatalytic oxidation ability, high photo corrosion resistance, and non-toxic properties (Huang et al, 2016). In the VOC degradation process several intermediates including carbon monoxide can be formed interfering with the complete removal of VOCs.…”

Decomposition Characteristics of Toluene Vapor Using Titanium Dioxide Photocatalyst and Zeolite Thermally Sprayed on an Aluminum Fiber Filter

“…For air purifying, malodorous gas treating and treatment of volatile organic compounds (VOCs) have been developed [1][2][3][4][5]. Such devices are utilized mainly in indoor environments [1,2,5,6]. However, if the devices using photocatalyst can be used in the work environment, they are available for workplaces where ventilation is limited.…”

“…Recently, photocatalytic technology using oxidation-reduction reaction of titanium dioxide (TiO 2 ) has been developed, applying air and water purification, antibacterial and antifungus agents. For air purifying, malodorous gas treating and treatment of volatile organic compounds (VOCs) have been developed [1][2][3][4][5]. Such devices are utilized mainly in indoor environments [1,2,5,6].…”

“…In this study, we investigated the basic decomposi- Methods Figure 1 shows a schematic diagram of the experimental apparatus. Two sheets of filters with titanium dioxide (TiO 2 ) photocatalyst and hydrophobic type zeolite (HiSiv TM 1000, Union Showa, Tokyo, Japan) (TiO 2 : zeolite = 9 : 1), which were prepared simultaneously by thermal spraying on aluminum fibers (Fiber diameter : 100 μm) were set in an air cleaner (MaSSC Clean MC-V, Fujico, Kitakyushu, Japan) (2) and placed in a chamber made of stainless steel (volume 150 l) (1). An ultraviolet (UV) lamp and fan of the air cleaner could be operated individually by ON/ OFF switches that were placed outside of the chamber.…”