Microstructural and electron framework-engineered 3D NiSeP-integrated CuFe composites as trifunctional electrocatalysts for sensing and urea-assisted water-splitting applications

Abstract

The development of catalytically dynamic, self-supporting, and cost-effective electrodes equipped with efficient trifunctional catalytic microarchitectures is pivotal in addressing the emerging demands of the healthcare and energy sectors. For the first time, this research reports the strategic integration of three-dimensional Se and P-fused NiSeP (NSP) microflakes with CuFe (CF) composite cubes anchored over an inherently capacious nitrogen-doped carbonized wood (NCW) (NSP-CF@NCW) and explores the impact of diverse strategies of electron and microstructural engineering of electrocatalytic sites on the trifunctional performances for enzyme-free urea sensing and urea electrolysis. Among the array of built electrodes, the NSP-CF@NCW electrode exhibits excellent multifaceted electrocatalysis ability triggered by the synergistic effects of highly voluminous and interconnected NSP flakes anchored over the CF composite, which results in unique electron channeling for efficient electrocatalytic kinetics. The NSP-CF@NCW electrode as a urea sensor exhibits momentous sensitivities of 33.1 and 7.0 mA mM⁻¹ cm⁻² accompanied with the corresponding broad linear ranges of 0.01–0.5 mM and 0.5–9.0 mM, respectively, and a detection limit of 0.0085 mM (S/N = 3). Moreover, as a urea electrolyzer, the best-performing electrode requires an overpotential of 1.49 V to deliver a high current density of 50 mA cm⁻², which is 210 mV lower than that required for the standard alkaline water splitting reaction.