Oxygen Vacancy Engineering Synergistic with Surface Hydrophilicity Modification of Hollow Ru Doped CoNi-LDH Nanotube Arrays for Boosting Hydrogen Evolution.

Abstract

With the development of clean hydrogen energy, the cost effective and high-performance hydrogen evolution reaction (HER) electrocatalysts are urgently required. Herein, a green, facile, and time-efficient Ru doping synergistic with air-plasma treatment strategy is reported to boost the HER performance of CoNi-layered double hydroxide (LDH) nanotube arrays (NTAs) derived from zeolitic imidazolate framework nanorods. The Ru doping and air-plasma treatment not only regulate the oxygen vacancy to optimize the electron structure but also increase the surface roughness to improve the hydrophilicity and hydrogen spillover efficiency. Therefore, the air plasma treated Ru doped CoNi-LDH (P-Ru-CoNi-LDH) nanotube arrays display superior HER performance with an overpotential of 29mV at a current density of 10mAcm-2 . Furthermore, by assembling P-Ru-CoNi-LDH as both cathode and anode for two-electrode urea-assisted water electrolysis, a small cell voltage of 1.36V is needed at 10mAcm-2 and can last for 100h without any obvious activity attenuation that showing outstanding durability. In general, the P-Ru-CoNi-LDH can improve the HER performance from intrinsic electronic structure regulation cooperated with extrinsic surface wettability modification. These findings provide an effective intrinsic and extrinsic synergistic effect avenue to develop high performance HER electrocatalysts, which is potential to be applied to other research fields.