High-speed graphene@Ag-MnO₂ micromotors at low peroxide levels

Area of Science:

• Materials Science and Engineering
• Nanotechnology
• Chemical Engineering

Background:

• Platinum (Pt)-based micro/nanomotors (MNMs) are widely used but suffer from high cost and potential toxicity.
• There is a significant demand for efficient, low-cost, and biocompatible MNMs for diverse applications.
• Developing fuel-efficient MNMs operating in low-concentration hydrogen peroxide (H2O2) is a key challenge.

Purpose of the Study:

• To develop novel platinum-free micro/nanomotors (MNMs) with enhanced performance.
• To investigate the efficiency of manganese dioxide (MnO2)-based MNMs in low hydrogen peroxide (H2O2) concentrations.
• To explore the potential of these MNMs for practical applications in biomedical delivery and environmental remediation.

Main Methods:

• Cathodic electrofabrication was employed to synthesize modified MnO2-based microtubes and microrods.
• Graphene/Ag-MnO2 micromotors were fabricated and tested for propulsion efficiency.
• The effect of surfactants on motor speed regulation was investigated in varying H2O2 concentrations.

Main Results:

• The synthesized Ag-MnO2 micromotors demonstrated high efficiency in hydrogen peroxide (H2O2) concentrations as low as 0.2%.
• Motor speed was effectively regulated using a surfactant, with maximum speeds exceeding 1.3 mm/s in 0.5% H2O2.
• Propelling force and output power were significantly higher (3.4 and 10 times, respectively) than state-of-the-art Pt-based micromotors.

Conclusions:

• Cathodic electrofabrication offers a viable route to produce efficient, platinum-free MnO2-based micro/nanomotors (MNMs).
• These novel Ag-MnO2 MNMs exhibit superior performance characteristics compared to existing Pt-based counterparts.
• The developed MNMs hold great promise for practical applications, including targeted biomedical delivery and environmental decontamination.