Facile synthesis of CeO2-decorated W@Co-MOF heterostructures as a highly active and durable electrocatalyst for overall water splitting

Rational coupling of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalysts is extremely important for practical overall water splitting; however, it is still challenging to construct such bifunctional heterostructures. Herein, a CeO2/W@Co-MOF/NF bifunctional electrocatalyst was prepared via a two-step in situ growth method involving an electrodeposition process. The incorporation of the W element enhanced the electronic interaction and enlarged the electrochemical surface area. After the electrodeposition of CeO2, the obtained CeO2/W@Co-MOF/NF possessed abundant heterointerfaces with a modulated local distribution, which promoted water dissociation and rapid electrocatalytic kinetics. In particular, it required very low overpotentials of 239 mV and 87 mV to reach a current density of 10 mA cm(-2) in OER and HER, respectively. A corresponding alkaline electrolysis cell afforded a cell voltage of 1.54 V at 10 mA cm(-2) to boost overall water splitting. This work provides a feasible strategy to fabricate MOF-based complexes and explores their possible use as bifunctional catalysts toward overall water splitting.