NiCo2O4 with changed catalytic process and enhanced catalytic property as mimic enzyme by introducing Mo6 +

Abstract

The modification of transition metal oxide by introducing with heteroatoms is a valid strategy to enhance artificial enzyme activities benefited from the change of the catalytic process and electronic properties. Herein, a simple hydrothermal method has been used to fabricate Mo-NiCo2O4 (MNCO) via introducing Mo6+ into NiCo2O4 (NCO). Compared with pure NiCo2O4, the acquired NiCo2O4 (MNCO) with the introduction of Mo exhibits better catalytic activity of peroxidase mimic enzyme. More interesting, only·O2- and h+ can be captured during catalytic process when MNCO as artificial enzyme, while·OH,·O2- and h+ can be found in the presence of NCO. Meanwhile, after the introduction of Mo, electron transfer has been drastically accelerated which contributed to the enhanced peroxidase-like activity. The Km value of H2O2 of NCO is 49-fold higher than that of MNCO, indicating that better affinity between MNCO and H2O2. And the LOD (detection limit) of MNCO is 22 times lower than that of NCO in the detection of H2O2. Based on excellent peroxidase-like active, a sensing platform for detecting hydroquinone in seawater is designed, confirming the great practicability in sensing fields.