The optimum process for preparing nanometer nickel oxide by the citrate-gel method was studied.

Ultrafine nickel oxide powder, a nano-metallic material, has been used in many areas, such as catalysts, battery materials, adhesives and other hard alloy.

This paper introduces the current situation of several nano-powder material in commercials production , including nano - TiO2 , nano - ZnO, nano - CaCO3 , nano - Ni powder.