ZIF-derived porous carbon composites coated on NiCo2S4 nanotubes array toward efficient water splitting

It is highly desired but challenging to grow self-supporting zeolitic imidazolate framework (ZIF) derived carbon hybrids with well-aligned superstructures for various electrocatalytic applications. In this work, we present the controlled synthesis of ZIF-based carbon hybrid arrays using selfsupporting NiCo2S4 nanotube arrays as self-sacrificing templates. Different from other reported carbon coated NiCo2S4 arrays with solid surfaces, the obtained NiCo2S4@NiCo/N-doped porous carbon array (NiCo2S4@NiCoNC/CC) have well-developed porous hollow structure and ultrafine NiCo nannoparticles deposited on the surface, which can provide facilitated channels and sufficient active sites for water electrolysis. The NiCo2S4@NiCoNC/CC exhibits superior catalytic performance for both hydrogen evolution reaction and oxygen evolution reaction with high efficiency in alkaline solution, achieving small overpotentials of 81 and 280 mV at the current density of 10mA cm(-2), respectively. Moreover, the NiCo2S4@NiCoNC/CC electrode shows excellent stability over 16 h of operation due to the robust structure of the electrode. The proposed strategy is highly promising for the rational design of well-aligned ZIF derived carbon hybrid arrays with desired morphology and composition on various substrates towards various electrocatalytic fields.