Fabrication of Screen-Printed Electrodes Modified by Hydrothermal MnO2 Microflowers and Carbon for Electrochemical Sensors in Copper Ions Detection

Porous MnO2 microflowers with a hexagonal crystalline structure were facilely prepared at a low hydrothermal temperature of 90°C, without using any template or capping agent. The as-prepared MnO2 only presented an excellent detection ability for copper (II) by a square wave anodic stripping voltammetry in the presence of super P carbon black as conducting agent, and Nafion as binder. In the present work, to evaluate the detection ability of copper (II) in the MnO2 microflowers, chips of screen-printed electrodes (SPEs) having a polyurethane substrate, a silver working electrode, a carbon counter electrode, and a silver pseudoelectrode, were designed. Then, the SPEs chips were modified with MnO2 microflowers and/or super P carbon and used as electrochemical sensors for the detection of copper (II) present in water sources. From the measured results, the fabricated sensors with excellent copper detection in a linear range from 0.625 nM to 15 nM (R2 = 0.9737), and a low detection limit (0.5 nM), high sensitivity (214.05 μA/cm2 nM), and rapid response (180 s) demonstrated high application potential for electrochemical sensors in the detection of copper in water resources.

A porous hierarchical micro/nano LiNi0.5Mn1.5O4 cathode material for Li-ion batteries synthesized by a urea-assisted hydrothermal method

The U/TM ratio has a significant influence on the phase composition, particle morphology and size of the carbonate precursor, thus leading to different electrochemical properties of the LiNi_0.5Mn_1.5O₄ material.

Synthesis of Ag–HNTs–MnO2 nanocomposites and their application for nonenzymatic hydrogen peroxide electrochemical sensing

Flower-like Ag–HNTs–MnO₂ nanocomposites have been synthesized successfully and they were used for fabricating a non-enzymatic hydrogen peroxide (H₂O₂) sensor.