This review summarizes various advantages of supercritical hydrothermal methods for the synthesis of innovative materials. The merits of supercritical water, that is, higher miscibility with organic materials and gases, controllable oxidizing and reducing atmosphere, faster mass transport and reaction, and environmentally benign property, allow the synthesis of various innovative nanomaterials at an industrial scale. By using supercritical water, we have successfully synthesized organic-inorganic hybrid nanomaterials, where organic molecules attach on the surface of metal oxide nanocrystals. The surface chemical character of the synthesized hybrid nanomaterials can be finely tuned and allows us to hybridize them with organic materials including polymers and plastics.
