Preparation of hierarchical porous metallic materials via deposition of microporous particles

It is the first time to report the preparation of hierarchical porous molybdenum (Mo) metal materials containing interconnected pores with a wide size range from sub-millimeter down to micrometer and nanometer scale. Microporous Mo particles were deposited in bimodal molten states, i.e. limited-molten and semi-molten state, by thermal spraying. In as-sprayed coatings, hierarchical macro/microporous structures were produced with macropores formed among solid particles and micropores remained in limited-molten particles. After annealing in a reductive atmosphere, Mo oxides inside semi-molten particles were reduced and nanometer pores were further created. Therefore, the as-received deposits exhibited multi-modal hierarchical pores with high open porosity and high specific surface area, which are promising for functional applications.