A composite includes a substrate, a binder layer disposed on a surface of the substrate; and a nanofiller layer comprising nanographene and disposed on a surface of the binder layer opposite the substrate. In addition, a nano-coating layer for coating a substrate includes multiple alternating layers of the binder layer and the nanofiller layer. Articles coated with the nano-coating layer prepared from alternating layers of nanofiller layer and binder layer have improved barrier properties, and may be used in down-hole applications.