Since I moved to Nagano prefecture, I have worked for my thesis. I spent really much time for it. I went to university almost everyday, even on weekends and Christmas, New year holidays. I had felt so depressed until I got good experimental results because I need to fix the machine first which has a lot of problems. For one experiment, it takes more than 6 hour. I felt like I was wasting time because I have to wait for several minutes every one operation. but, at last, I could succeed in fixing machine and could operate properly and got awesome results. After that, I got interested in my thesis. Let me write about my thesis with easy words.

My thesis is about TiO2 Photocatalyst, which is catalysis and reacts under only Ultraviolet light irradiation. TiO2 can decompose organic matter and is used to remove the bad smell, harmful gas, and so on. The recent research said they suceeded in making a sample which can reacts under both Visual light and Ultraviolet light irradiation by attaching iron and dope nitrogen. In this thesis, I checked the photocatalytic activity.

My senior made a sample and examined the photocatalytic activity by observing the decrease of acetaldehyde. However, the concentration of acetaldehyde fluctuated and couldn't observe the decrease clearly. In this thesis, I make that fluctuation flat and check the photocatalytic activity again based on my senior thisis.

First of all, I checked the performance.

I filled acetaldehyde and air in the Tedler bag. Then, checked the concentration of acetaldehyde every several minutes for hours by injecting the gas filled in the tedler bag into Gas Chromatography(GC).

This pic is the result of the experiment. It showed the fluctuation as my senior mentioned, so I attempted to fix the machine and experiment.

This fluctuation could be seen due to the various factors. I solved the problems and fix those factors.

At last, I could succeed in making the concentration stable. Then, I thought I could examine the photocatalytic activity properly, so I made a sample of photocatalyst which can be reacted under Visual light.

First, I put normal TiO2 into the bag. Then, I observed the decrease of acetaldehyde under dark box, Visual light, and Ultraviolet light respectively.

I could see the decrease of acetaldehyde only when I put TiO2 under the Ultraviolet light. It means, normal TiO2 reacts under only ultraviolet light.

Second. O put TiO2 with attached iron and doped nitrogen. Then I experimented in the same way as the first experiment.

I could see the decrease acetaldehyde only when I put TiO2 under the Ultraviolet light and Visual light. It means, normal TiO2 reacts under ultraviolet light and Visual light.

For these result, the TiO2 changed to the one which can be reacted under Visual light.

In conclusion, TiO2 can come to react under Visual light by attaching iron and doping nitrogen.

This is the Photocatalytic item sold in the all-100-yen shop. however, you can see the note of caution 'this only works under Ultraviolet light included in 3 % of sun light'. If we develop the TiO2 with attached iron and doped N, These kind of items will be more effective. It is awesome that we don't have to clean things thanks to this technology in near future.

What's my thesis about?