Unveiling the morphological influence of nitrogen-doped carbonized wood anchored 3D transition metal oxide microarchitectures on catalytic activity: A trifunctional electrocatalyst for sensing and energy conversion

Abstract

The rational construction and advancement of binder-free, self-standing, and cost-effective electrodes endowed with highly active trifunctional electrocatalysts represent a pivotal nexus between the research domains of energy and healthcare applications. However, the lack of proficient non-precious-metal trifunctional electrocatalysts bridging the aforementioned research domains remains a pinnacle barrier. Herein, we proposed distinct fabrication protocols to construct morphologically diverse three-dimensional (3D) CuO microarchitectures directly docked over the naturally inherited carbon channels of nitrogen-doped carbonized wood (NCW) (CuO@NCW) obtained by the carbonization of waste wood monoliths and explored the efficacy of different catalytic designs towards the trifunctional performances on non-enzymatic glucose sensing and glucose oxidation-assisted water splitting. Among the diverse binder-free engineered electrodes, CuO@NCW obtained via the facile electrodeposition (E) route (dubbed as CuO-E@NCW) demonstrated proficient electrocatalytic trifunctionality benefitting from the allied merits of the robustly anchored 3D porous dendritic architectures equipped with ample porosity and momentous interconnectivity. The as-fabricated CuO-E@NCW electrode as a glucose sensor displays two broad linear ranges between 0.01 and 0.5 mM and 0.5–4.0 mM with corresponding elevated sensitivities of 24.6 and 7.2 mA mM−1 cm−2, with a lower limit of detection of 0.0013 mM (S/N = 3). Besides, this best-performing electrode delivers a high current density of 50 mA cm−2 with a low cell voltage of 1.39 V in the glucose electrolysis system, which is 170 mV lower compared with stereotypical alkaline water splitting.