Preparation Of Manganese-based Spinel Nano-oxides And Their Electrocatalytic H₂O₂ Sensitive Properties

Hydrogen peroxide(H2O2),as a kind of stable active oxygen,not only plays an important role in the process of physiological activities,but also is closely related to human environmental,life and health.It is of great practical significance to detect H2O2 quicklyand accurately.In recent years,the nano-structured spinel-type AB2O4 bimetallic oxides,especially manganese-based spinel oxides has been considered to be a promising electrochemical sensing detection H2O2 electrical catalystbecause of their excellent conductivity and catalytic activity.Based on this,three manganese-based spinel nano-oxides were synthesized in the thesis,and modified on the surface of bare glassy carbon electrode(GCE)to construct non-enzymatic electrochemical sensors with good performance.The valence state of Mn is regulated by the change of A-site metals(Zn,Co,Cu),thereby realizing the highly sensitive detection of H2O2 by manganese-based spinel compounds.At the same time,the mechanism of electrocatalytic H2O2 is discussed in detail.The results show that the above three manganese-based spinel nanomaterials all show good electrochemical sensing performance for H2O2.Among them,the linear detection range(0.0012-100.4 mM)of hollow nanosphere CoMn2O4/GCE electrode has been the widest among the spinel oxide-based electrochemical H2O2 sensors reported so far.In particular,the nano-flakes CuMn2O4/GCE electrode shows ultra-sensitive detection ability for H2O2,with a high sensitivity of 3420.2 ?A mM-1 cm-2 and a relatively low detection limit(12 nM).In addition,the above-mentioned sensors all show good anti-interference ability and longterm stability,and can be used for accurate detection of trace H2O2 in rat serum,commercial disinfector and milk.Therefore,the work of this paper provides a useful reference for the synthesis of other spinel-type oxide electrocatalytic H2O2 sensitive materials.