Flexible design in controllable synthesis of Ru catalyst toward enzymatic and electrochemical hydrogen peroxide performance

Abstract

The ruthenium (Ru)-based functional structure has been well understood in catalytic performance due to its special particularity in structural fabrication. In this work, the controllable synthesis of core–shell Ru nanomaterials is first reported, which were not only realized via ice bath conditions with amorphous characterization but also showed a flexible design in the controllable synthesis of crystalline Ru after high intensity focused ultrasound (HIFU) treatment. The achieved amorphous Ru particles (∼115 ± 3 nm) and crystalline Ru (∼5 ± 0.5 nm) exhibit hydrogen peroxide catalytic performance and can be considered as an electrochemical sensing platform. The K_m value of core–shell Ru for 3,3′,5,5′-tetramethylbenzidine (TMB) was 0.221 mM, which exhibits higher affinity for TMB and prominent catalytic performance than horseradish peroxidase (HRP). For selectivity and sensitivity towards the detection of H₂O₂ molecules, it expressed a wide linear range from 0.5 to 100 mM with an H₂O₂ detection limit of 1.45 μM (S/N = 3) and a sensitivity of 2.07 μA μM⁻¹. After HIFU treatment, the diameter of the achieved crystalline Ru was about one-twentieth that of the core–shell Ru structure. An enhancement in catalytic performance was observed as a sensor platform for detecting H₂O₂, its detection range was wider, from 0.5 to 110 mM, its limit of detection was 0.007 μM (S/N = 3), and it exhibited a higher sensitivity of 443 μA μM⁻¹. Hence, this flexible design in the synthesis of Ru NMs (amorphous and crystalline in status) could provide a novel synthetic strategy and make achievements in catalytic performance.