Demonstrating Online Monitoring of Air Pollutant Photodegradation in a 3D Printed Gas-Phase Photocatalysis Reactor

Abstract

We present a demonstration of online monitoring of gas-phase photocatalytic reactions. A cotton cloth impregnated with commercial titanium dioxide nanoparticles is used as a photocatalytic filter to clean air contaminated with a model pollutant. A fan forces air through the filter while it is irradiated by UV diodes. The concentration of the air pollutant is measured online by an inexpensive, commercially available semiconductor air quality sensor. The structural parts of the reactor were 3D printed in polylactide bioplastic. We provide all schematics, 3D printed model parts, hardware, firmware, and computer code of the reactor and control units. The device can be used for interactive learning of both gas phase photocatalysis and gas sensing, as well as in student laboratory classes for measuring air pollutants and their photodegradation. The experimental setup can also form the basis for a project work for chemical engineering university students, and it can be employed as a building block for development of other gas phase chemical reaction demonstrations.

Photocatalytic Activity of Nanostructured Titania Films Obtained by Electrochemical, Chemical, and Thermal Oxidation of Ti6Al4V Alloy—Comparative Analysis

“…TiO 2 materials and nanomaterials, now are often used in various applications, such as self-cleaning surfaces [1][2][3], anti-fogging mirrors [4,5], antimicrobial coatings, [6][7][8][9] electrochromic devices [10][11][12], rechargeable batteries [13,14], and sensors [15,16]. They can also be applied in medicine [17][18][19][20], automotive [21,22], and in photocatalytic environmental cleaning of water and air [23][24][25][26]. For these applications, the crystalline form of TiO 2 (anatase and rutile) are mostly used and additional density functional theory (DFT) calculations, which are intended to define the electronic structure, energy band gap, and defects level, are applied [27].…”

Photocatalytic air-purification: a low-cost, real-time gas detection method

“…Emerging analytical methods have also recently been 11 regarding cost and ease of use. In another interesting educational study, Stefanov et al 15 employed commercially available semiconductor gas sensors in a 3-D printed photocatalysis reactor. However, using such sensors require supporting electronics for digital readout and is not a "ready-to-use" gas detection system.…”

Metal Oxide Nanorods-Based Sensor Array for Selective Detection of Biomarker Gases

“…Based on these needs, monitoring the harmful gases present in the environment or breathing has been extensively concentrated as a suitable healthcare approach [ 4 ]. In general, indoor air quality is contaminated by harmful gases emitted from building materials, furniture, and appliances, which induce dizziness, paralysis, dyspnea and eventually lead to a comatose state [ 5 ]. These gases contain a lot of chemical vapors (NO 2 , CO, NH 3 , and volatile organic compounds (VOCs)) at different concentrations ranging from parts per billion (ppb) to parts per million (ppm) [ 6 ].…”