Facile hydrothermal synthesis NiHPO₃·H₂O nanorods, influencing factors, and transformation toward Ni–NiO composite nanostructures, catalytic properties and application in sensing for glucose

We designed a direct and simple route, based on a thermal decomposition method under normal atmospheric pressure for obtained Ni–NiO nanorods from NiHPO₃·H₂O nanorods structures, the uniform precursor. This process includes the synthesis of the precursor through a facile hydrothermal approach and subsequently thermal decomposition of the precursor under air atmosphere. Some factors influencing the precursor of the NiHPO₃·H₂O nanorods structures were systematically investigated. After the heat treatment, the as-synthesized Ni–NiO nanorods with a well retained structure and the catalytic performance were investigated. It was found that the Ni–NiO nanorods exhibited good catalytic activity for the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in excess NaBH₄ solution. Furthermore, experiments showed that the as-prepared Ni–NiO nanorods presented high electrochemical response with low detection limit (0.254 μM), wide linear range (0.25–1.75 mM) (R² = 0.99918) and high selectivity in 0.1 mol L⁻¹ NaOH solution and could be used as an electrochemical sensor for the detection of glucose.