Scalable Synthesis of Bimetallic Phosphide Decorated in Carbon Nanotube Network as Multifunctional Electrocatalyst for Water Splitting

Abstract

It is challengeable to obtain a scalable method to synthesize nonprecious electrocatalysts with high efficiency and stability for overall water splitting, to replace the costly and scarce noble metal based electrocatalysts (e.g., Pt- and Ru-based materials). Herein, bimetallic (Fe, Co)P nanoparticles decorated in carbon nanotube network (FCP-CN) are synthesized through a facile and scalable spray drying and subsequent phosphorization process. The FCP-CN hybrid delivers excellent performance in hydrogen evolution reaction both in acidic and alkaline media, oxygen evolution reaction, and overall water splitting: it possesses an Pt-like hydrogen evolution reaction activity with an ultralow onset overpotential of 18 mV in acid; remarkably, it shows an ultrasmall Tafel slope of 38 mV dec–1 in oxygen evolution reaction; being employed as both cathode and anode, this catalyst demonstrates promising performance of overall water splitting with high long-term stability. The performance is superior among recently reported transition-metal-based catalysts for overall water splitting. This work provides a scalable and low-cost synthesis strategy to synthesize nonprecious and multifunctional transition-metal-based catalysts with unique nanoarchitecture and outstanding catalytic performance for water splitting.