Abstract
Design and synthesis of cost-effective electrocatalysts with remarkable activity and stability is highly desirable for renewable energy devices. Herein, we have successfully constructed sheet-like CoMoO4–Co(OH)2 and CoMoP–CoP arrays on nickel foam (NF) through chemical etching ZIF-67 arrays and phosphorization in sequence. Series CoMoO4–Co(OH)2/NF as anode and CoMoP–CoP/NF as cathode showed excellent electrocatalytic activity and stability in alkali water splitting, where the combined catalysts only need 1.67 V cell voltage to drive 10 mA cm−2 and obtain robust high current stability at 500 mA cm−2 for 110 h with almost no attenuation. In addition, using CoMoP–CoP/NF as the cathode of a Zn–H2O cell can provide a power density of 11.5 mW cm−2 and a stable 170 h for simultaneous H2 and electricity generation. The excellent performance of the system is attributed to the unique sheet-like array morphology of combined catalysts providing large surface area and rich pore structure conducive to electrolyte diffusion and gas emission, as well as the synergies between the different components providing more catalytic active sites.
Hierarchical CoMoO4–Co(OH)2 and CoMoP–CoP arrays on nickel foam (NF) are constructed by chemical etching ZIF-67 arrays and phosphorization in sequence. Series CoMoO4–Co(OH)2/NF as anode and CoMoP–CoP/NF as cathode require only a cell voltage of 1.67 V to drive 10 mA cm−2 and obtain robust high current stability at 500 mA cm−2 for 110 h with almost no attenuation in a two-electrode system. [Display omitted]
•CoMoO4–Co(OH)2 and CoMoP–CoP nanosheets on nickel foam are precisely fabricated by a controllable method.•Both catalysts exhibited high electrocatalytic activity and stability for OER and HER, respectively.•The two catalysts constructed overall water splitting system shows robust activity and stability.•The unique structure and strong electronic interactions between the different components lead to excellent performance.