The Light Clean Revolution
Photo-Catalytic Technology | page 1 of 8
Article from Look Japan July 2002 Issue
Aoki Shin'ichi explains how recent developments in photocatalytic technology will make life in the twenty-first century safer and more convenient.
A new technology developed by University of Tokyo professor Fujishima Akira is attracting a lot of attention. Fujishima uses photocatalysts and irradiation to break down chemicals. In addition to helping make anti-bacterial tile and air-purification devices, other promising applications of this photocatalyst technology continue to come to light. Japanese scientists are leading the world in every area of thisfield from basic research to applications.
Take the UST-TSU building standing in front of the central train station in Tsu City, the capital of Mieken (prefecture). The building's outside walls are covered with photocatalytic tiles which, according to Tsu's city planning department, have two functions. First, dirt and soot have a hard time adhering to the tiles, which lowers costs for cleaning the building and repairing the tiles. Second, the tiles cleanse the air of pollutants such as NOx gases, which contribute to asthma. The tiles covering the UST-TSU building, some 7,700 square meters of them, reportedly have the same purifying effect on the air as a forest of 200 poplar trees.
The titanium oxide used in the photo-catalysts exhibits two properties when exposed to ultraviolet light: an extremely high affinity for water and a high oxidation potential. Titanium oxide readily sheds water, but when exposed to ultraviolet light it develops a strong affinity for water, known as hydrophilicity.
When water comes in contact with the highly hydrophilic coating of the UST-TSU building, the water immediately spreads over the entire surface in a thin, uniform film. Thus, when dirt or soot settles on the building, it actually floats on top of the thin film of water coating the tiles. When rain comes, it washes the dirt away.
Aoki Shin'ichi explains how recent developments in photocatalytic technology will make life in the twenty-first century safer and more convenient.
A new technology developed by University of Tokyo professor Fujishima Akira is attracting a lot of attention. Fujishima uses photocatalysts and irradiation to break down chemicals. In addition to helping make anti-bacterial tile and air-purification devices, other promising applications of this photocatalyst technology continue to come to light. Japanese scientists are leading the world in every area of thisfield from basic research to applications.
Take the UST-TSU building standing in front of the central train station in Tsu City, the capital of Mieken (prefecture). The building's outside walls are covered with photocatalytic tiles which, according to Tsu's city planning department, have two functions. First, dirt and soot have a hard time adhering to the tiles, which lowers costs for cleaning the building and repairing the tiles. Second, the tiles cleanse the air of pollutants such as NOx gases, which contribute to asthma. The tiles covering the UST-TSU building, some 7,700 square meters of them, reportedly have the same purifying effect on the air as a forest of 200 poplar trees.
The titanium oxide used in the photo-catalysts exhibits two properties when exposed to ultraviolet light: an extremely high affinity for water and a high oxidation potential. Titanium oxide readily sheds water, but when exposed to ultraviolet light it develops a strong affinity for water, known as hydrophilicity.
When water comes in contact with the highly hydrophilic coating of the UST-TSU building, the water immediately spreads over the entire surface in a thin, uniform film. Thus, when dirt or soot settles on the building, it actually floats on top of the thin film of water coating the tiles. When rain comes, it washes the dirt away.
