CeO 2 /CuO/NiO hybrid nanostructures loaded on N-doped reduced graphene oxide nanosheets as an efficient electrocatalyst for water oxidation and non-enzymatic glucose detection.

In this work, the three-component heterostructure of CeO 2 /CuO/NiO was synthesized by a co-precipitation procedure and heating at a temperature of 750 °C. Then, CeO 2 /CuO/NiO nanoparticles were successfully supported on N-doped reduced graphene oxide (N-rGO) by a hydrothermal method. The obtained nanomaterials were used as effective electrocatalysts for the oxygen evolution reaction and glucose sensing in an alkaline medium. The results indicated that when CeO 2 /CuO/NiO is anchored on N-rGO nanosheets, active catalytic sites increase. On the other hand, N-doped rGO enhances electrical conductivity and electron transfer for water or glucose oxidation. CeO 2 /CuO/NiO@N-rGO has a large electrochemically active surface area and more active catalytic positions, and thus exhibits high activity for the OER with a low overpotential of 290 mV, a suitable Tafel slope of 110 mV dec -1 , and superior stability and durability for at least 10 hours. CeO 2 /CuO/NiO@N-rGO can also detect glucose with a high sensitivity of 912.7 μA mM -1 cm -2 , a low detection limit of 0.053 μM, a wide linear range between 0.001 and 24 mM, and a short response time of about 2.9 s. Moreover, the high selectivity and stability of this electrode for glucose sensing show its potential for clinical applications.