We explored a new bio-safe and bio-compatible route for the synthesis of oxide nanomaterials using water as solvent as well as source of oxygen. The use of water as a reagent is particularly attractive because it is safe, inexpensive, environmentally benign and bestowed with many virtues especially under supercritical conditions. The simple and straightforward route is based on simple reaction of water and metal powder at relatively low temperature. Since water is regarded as a benign solvent and non toxic, the product (nanostructures) could be used safely for biomedical and other applications, including sensors. In addition, the method is simple, straightforward, economical, environmentally benign, involves green chemistry, which can make it suitable for scale large production. The prospects of the process are bright and promising. There are number of applications including energy and environment which shall be discussed during the talk.