In Situ Electrochemical Oxidation Synthesis of SyA-Cu/CuO/NF Heterostructure As Trifunctional Electrocatalyst for UOR, BOR, and HER at Industrial-Scale High Current Density
Gang Xu, Jin‐Kun Li, Wenbiao Wang, Shi-Jiao Dong, Mei‐Qing Cai, Ximin Zhang, Jun‐Ling Song
Abstract
The construction of bifunctional or trifunctional electrocatalysts with excellent performance for highly effective overall water splitting is highly desirable and extremely challenging. Herein, Cu-based metal–organic frameworks (MOFs) nanomaterials using syringic acid (SyA) as ligands are grown on nickel foam (NF) by a one-step solvothermal method, namely, the self-supported precursor (SyA-Cu/NF); further, a SyA-Cu/CuO/NF heterostructure is obtained by in situ electrochemical oxidation of these precursors, which is applied to the urea oxidation reaction (UOR) and benzyl alcohol oxidation reaction (BOR). The optimal SyA-Cu/CuO/NF heterostructure could reach 100 mA cm –2 on only applying 1.47 V (vs RHE) with a Tafel slope of 53 mV dec –1 for UOR and 1.44 V with a Tafel slope of 32 mV dec –1 for BOR. Furthermore, it also displays hydrogen evolution reaction (HER) activity, showing a low overpotential of 92 mV at 10 mA cm –2 . Above all, coupling UOR and BOR, it is used as a bifunctional electrocatalyst for the overall water splitting, which can reach 10 mA cm –2 at 1.47 and 1.45 V, respectively. Therefore, this SyA-Cu/CuO/NF heterostructure is a potential trifunctional electrocatalyst for UOR, BOR, and HER due to its unique interface interaction between SyA-Cu/CuO and the intermediates/electrolyte.