Methods for making bifunctional porous non-noble metal phosphide catalyst for overall water splitting, electrodes for overall water splitting, and methods for electrocatalytic water splitting

A method of manufacturing a bifunctional electrocatalyst for overall water splitting comprising oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), the method comprising:

• growing electrocatalyst comprising primarily metallic phosphides on a three-dimensional substrate comprising a metallic foam by:
• immersing the substrate in an iron nitrate solution to form a once disposed substrate;
• subjecting the once disposed substrate to thermal phosphidation with phosphorus powder under inert gas to grow metal phosphides thereupon and form a once subjected substrate;
• cooling the once subjected substrate to form a cooled, once subjected substrate;
• immersing the cooled, once subjected substrate in an iron nitrate solution to form a twice disposed substrate;
• and
• subjecting the twice disposed substrate to thermal phosphidation with phosphorus powder under inert gas to provide an electrode comprising the bifunctional electrocatalyst on the three-dimensional substrate,
• wherein the metallic phosphides comprise iron phosphide (FeP) and dinickel phosphide (Ni2P).