Obtaining Ni-P electrocatalyst in minutes via electroless plating on carbon nanotubes decorated substrate for alkaline urea electrolysis

Urea electrolysis has received extensive attention recently, because it can cost-effectively produce ultrapure hydrogen by coupling with electro-oxidation of urea. Despite the myriad of reported materials, it is still challenging to obtain electrocatalysts in an efficient manner that can effectively integrate the electrocatalytically active species with the electrically conductive substrate. In responses to this issue, the present work reveals that amorphous NiP can be incorporated onto carbon nanotubes decorated Ni foam (CNTs/NF) substrate by a three-minute electroless plating process. The obtained NiP/CNTs/NF electrocatalyst is confirmed to undergo surface reconstruction in alkaline electrolyte forming hydrated Ni(OH)(2) nanocrystals, exhibiting promising electrocatalytic performance with high achievable current responses (similar to 400 mA cm(-2)), low Tafel slope (21 mV dec(-1)), and large reaction rate constant (1.1 x 10(6) cm(3) mol(-1) s(-1)) for urea oxidation. Moreover, combining NiP/CNTs/NF and commercial Pt/C in a single device, the urea electrolyzer renders the current responses of 10, 50, and 100 mA cm(-2) at the cell voltage of 1.42, 1.60, and 1.79 V, respectively, reflecting energy-saving hydrogen production and remediation of urea-containing wastewater concurrently. This work paves the way forward for obtaining highly efficient electrocatalyst via a simple and scalable approach.