A general strategy for constructing transition metal Oxide/CeO2 heterostructure with oxygen vacancies toward hydrogen evolution reaction and oxygen evolution reaction

In response to the ever-increasing energy crisis, hydrogen, as an ideal substitute for energy field, is gradually rolling into the public. Developing high-efficiency and earth-abundant non-noble metal electrocatalysts is considered as the key to electrolytic water technology. In this work, two-dimensional (2D) transition metal oxides (Co 3 O 4 or NiO)/CeO 2 heterostructures with rich oxygen vacancies (v-TMOs/CeO 2 HSs) have been successfully synthesized via a simple and general strategy. The as-synthesized Co 3 O 4 /CeO 2 HSs and NiO/CeO 2 HSs demonstrated outstanding bifunctional electrocatalytic performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline surroundings, supplying low overpotentials of at 10 mA cm −2 ( η 10 ) of 88 and 258 mV (Co 3 O 4 /CeO 2 HSs) as well as 99 and 265 mV (NiO/CeO 2 HSs). The 2D heterostructure and oxygen vacancies endow the v-TMOs/CeO 2 HSs with plentiful active sites and large active surface area, which can enhance the catalytic activity during the HER and OER. This work highlights a general strategy to fabricate the novel TMOs/CeO 2 catalysts with abundant oxygen vacancies, and provides the guidance for the rational construction of catalyst materials which can be devoted to the highly efficient HER and OER.