Nanotechnology, energy and the environment are three key hot topics included in green technologies present in all international challenges for the future. The urgency to identify and develop sustainable and timely solutions for our future society is demonstrated due to the alarming trends in global energy demand, the finite nature of fossil fuel reserves, the need to dramatically curb emissions of greenhouse gases (GHG) to mitigate the devastating consequences of climate change, the damaging volatility of oil prices and the geopolitical instability in supplier regions. This book examines several of these topics related to green chemistry in a multidisciplinary and unique book which covers the essence of green chemical technologies. The book also features top contributions from well-established and respected authors in world-wide research programs.