Graphdiyne reinforced multifunctional Cu/Ni bimetallic Phosphides-Graphdiyne hybrid nanostructure as high performance electrocatalyst for water splitting

Obtaining of non-noble metal catalyst with bifunctional effect for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in water splitting is highly desired to get high purity hydrogen. Here in, we design and fabricate Cu/Ni bimetallic phosphides with Graphdiyne (GDY) to form hybrid nanomaterial CuNiPx-GDY on Ni foam for the first time. The synergistical effect between GDY and transition metal phosphides, and the atomic scale heterojunctions between Cu₃P and Ni₂P, effectively accelerate the catalytical process both in HER and OER, resulting in extraordinarily small overpotentials of 178 mV and 110 mV at 10 mA cm⁻² for OER and HER in CuNiPx-GDY(1:1) in 1 M KOH, respectively. Density functional theory results show that, compared with pure CuNiPx, the introduced GDY can considerably improve the activity of OER and generate different active sites for OER and HER in CuNiPx-GDY(1:1). Thus CuNiPx-GDY(1:1) exhibits good catalytical performance and stability as catalyst for overall water splitting. This study provides a new sight into the structure and catalytic properties of GDY and transition metal phosphides hybrid nanomaterial, and also offers a new way to obtain advanced materials with remarkable catalytic properties.