The influences of shape and structure of MnO_2 nanomaterials over the non-enzymatic sensing ability of hydrogen peroxide

摘要

The different morphologies of MnO_2 nanomaterials such as rod, belt, and flower were synthesized through a facile hydrothermal method, and their phaseswere also effectively controlledwithout employing any organic surfactants. The growth mechanisms of prepared nanostructures has been rationalized through the observed morphologic and structural characterizations. The prepared MnO_2 nanostructures improved the electron transfer kinetics and minimized the overpotential and exhibited good electrocatalytic activities in detecting the hydrogen peroxide. Among the studied nanostructures, r-MnO_2 exhibited an excellent sensing behavior toward hydrogen peroxide, and a linear current response was observed for the hydrogen peroxide, ranging from 1 micromolar to 1.5 mMwith a high-sensitivity and low-level detection limit of 62.9 lAmM~(-1) cm~(-2) and 0.1 μM, respectively. Moreover, r-MnO_2-modified electrode exhibited high selectivity toward hydrogen peroxide and interference-free phenomenon for the other electroactive species.