MOF-Derived Zero-Dimensional Cu3P Nanoparticles Embedded in Carbon Matrices for Electrochemical Hydrogen Evolution

Calcination of metal-organic frameworks (MOFs) to prepare porous-carbon-based nanocomposites has emerged as a facile and viable method for various applications. Here, the Cu-based HKUST-1 MOF is chosen as the synthesis precursor and growth template owing to its large surface area, high pore volume, as well as facile and large-scale preparation. Through the direct phosphorization at elevated temperatures, a hierarchical porous matrix consisting of HKUST-1 MOF-derived zero-dimensional (0D) Cu3P nanoparticles embedded on the surface of conductive carbon matrices is produced in a single step, in which its hydrogen evolving electrocatalytic performances are assessed as a representative application. The Cu3P/C-300 composite, at a loading mass as small as 0.1 mg cm-2, demonstrates an overpotential of 233 mV at 10 mA cm-2and a Tafel slope of 91 mV dec-1for hydrogen evolution with robust durability in a 1 M KOH solution, which are both lower than other metal phosphides directly dropcasted onto the conductive substrates (overpotentials mainly >250 mV at 10 mA cm-2and Tafel slopes mainly >100 mV dec-1). Such an improved hydrogen evolution reaction performance is attributed to high specific surface area, improved interfacial contact with the conductive substrate, and the synergistic effects of the intrinsically active Cu3P nanoparticles of ultrasmall sizes with carbon matrices. The synthesis strategy may shed light on the development of cost-effective and stable electrocatalysts with excellent electrochemical performances in energy-conversion fields.