SUMMARY

We report a novel rapid CO 2 laser method for synthesizing binder-free catalysts, including a thin layer of high-entropy oxide (HEO) on nickel foam (HEO@NF). HEO@NF was further used as a binder-free catalyst for low-voltage glucose oxidation coupled with water electrolysis. A “work function engineering strategy” was introduced to boost the electro-oxidation performance of the catalyst, particularly for the glucose oxidation reaction (GOR), marking its first report in the literature. HEO@NF exhibits a low overpotential of 290 mV for the oxygen evolution reaction (OER) and a low oxidation potential of 1.22 V for the GOR at 10 mA cm −2 . It also shows excellent stability for both the OER and the GOR over 100 h at 50 mA cm −2 . 1 H NMR analysis reveals formic acid as the main product of glucose oxidation. In overall glucose oxidation coupled electrolysis, the HEO@NF||Pt/C/NF pair requires only 1.37 and 1.67 V to achieve a current density of 10 and 50 mA cm −2 , respectively. In situ Raman spectroscopy identifies the key role of A 1g corresponding to the octahedral site (MO 6) of spinel oxides in the GOR, whereas the formation of metaloxyhydroxide (MOOH) is observed in the OER. Density functional theory unveils iron as the main active site for the GOR and cobalt as crucial for the OER. Overall, CO 2 laser–assisted synthesis of HEO@NF highlights its potential for practical, low-energy hydrogen generation alongside glucose oxidation to value-added formic acid.