Hydrogen energy, a zero-carbon emission energy, is mainly produced by water electrolysis. Currently, precious metal Pt is the state-of-the-art electrocatalyst for hydrogen evolution reaction(HER). However, the high cost and scarcity of Pt limit its wide application. Thus developing non-noble-metal electrocatalysts with high activity and excellent durability in hydrogen evolution reaction is still a great challenge. Self-supporting transition metal phosphides have excellent catalytic activity and stability, which are expected to be an alternative to precious metal Pt-based catalyst for HER. In this paper, the research progress of self-supporting transition metal phosphides is presented in detail. The advantages and mechanism of these electrocatalysts are discussed emphatically:(1) The self-supporting substrate's 3D integrated frame with strong conductivity provides lots of channels for transferring electron, thereby accelerating the catalytic reaction process.(2) Comparing self-supporting catalysts with others, its greater specific surface and more active sites are critical for catalytic reaction.(3) Self-supporting transition metal phosphides can be directly used as cathode for HER, and avoid the trouble that catalysts easily fall off from the glass carbon electrode in traditional coating method. Finally, the prospective and challenges for future development of self-supporting transition metal phosphides for water electrolysis are summarized.
Contents
1 Introduction
2 Self-supporting transition metal phosphide electrocatalysts
2.1 Self-supporting cobalt phosphide catalysts
2.2 Self-supporting nickel phosphide catalysts
2.3 Self-supporting molybdenum phosphide catalysts
2.4 Self-supporting copper phosphide and iron phosphide catalysts
2.5 Self-supporting tungsten phosphide catalysts
2.6 Self-supporting bimetallic phosphide catalysts
3 Conclusion and outlook