Over the past few decades, mankind has observed an unprecedented and
remarkable growth in industry, resulting in a more prosperous lifestyle
for peoples of many countries. In developing countries, however,
explosive industrial growth is just now beginning to raise the living
standards of the people. Most industries, especially in these developing
countries, are still powered by the burning of fossil fuels; con-
quently, a lack of clean energy resources has caused environmental
pollution on an unprecedented large and global scale. Toxic wastes have
been relentlessly released into the air and water leading to serious and
devastating environmental and health problems while endangering the
planet and life itself with the effects of global warming. To address
these urgent environmental issues, new catalytic and photocatalytic
processes as well as open-atmospheric systems are presently being
developed that can operate at room temperature while being totally clean
and ef?cient and thus environmentally harmonious. Essential to
technologies harnessing the abundant solar energy that reaches the earth
are the highly functional photocatalytic proce- es that can utilize not
only UV light, but also visible light.