Photocatalytic Degradation of Formaldehyde
Mark Tan
Sir Winston Churchill
Floor Location : S 223 P

Each year, around 1.5 million deaths worldwide are caused directly or indirectly by interior contamination. Formaldehyde (CH2O) is one of the most hazardous and noxious pollutants found in many indoor environments. It is well documented that exposure to even fairly low levels of formaldehyde can bring about fatal effects. As of today, the most common way of eliminating formaldehyde is by using activated carbon filter paper. However, titanium dioxide (TiO2) is known to be able to catalyze the degradation of formaldehyde under UV light source. This original experiment tested whether coating titanium dioxide (TiO2) onto activated carbon paper can improve the effectiveness of the paper in removing CH2O and if the effectiveness of such paper is positively correlated to the percentage concentration of the TiO2. Four sheets of activated carbon paper were made using papermaking technique, three of which were impregnated in three different concentrations of titanium dioxide nano-particle suspensions, respectively 1%, 2% and 4%. Each sheet was placed into a photocatalytic reaction device and 50ppm of formaldehyde was injected into the vessel. The efficiency of the sheets to eliminate formaldehyde was tested under UV irradiation. To ensure the reliability of the data, the steps above, starting with the sheet-forming process, were repeated two more times. The results for all three trials showed that the three TiO2 coated activated carbon sheets were able to reduce considerably more formaldehyde from the environment at a faster rate than the plain activated carbon sheet could. However, the concentration of TiO2 on the activated carbon sheet had no effect on the final percent degradation of formaldehyde, which was the same (~49%) for all concentrations. The results were checked by modeling and statistical analysis to reinforce their reliability and accuracy.n Thus, as proven in my experiment, the photocatalytic paper I have created allows mass amounts of harmful chemicals, such as formaldehyde, to be removed from the air and degraded into harmless inorganic substances such as H2O, CO2. This type of photocatalytic sheet can be utilized in many common appliances like gas masks, air conditioners and air purifiers. Furthermore, because of its relatively low manufacturing cost, this type of paper can be widely applied in many areas of life. The elimination of formaldehyde is not only necessary in a home environment but also in factory settings where harmful pollutants still remain a major concern. This photocatalytic paper will ultimately be able to ensure the safety and wellbeing of families and workers alike all around the world.