Hollow nanospheres and monatomic amorphous metals (MAMs): the scope for electrochemical synthesis and processing

ABSTRACT

The synthesis of nanomaterials and their characterisation has been one of the pronounced trends in materials research over the last two decades. Lightweight, hollow nanospheres can show high surface area and permeability with high porosity and low density. Their cavities can host nanoparticles, dye molecules, drugs or enzymes. Monatomic amorphous metals, MAMs (or ‘metal glasses, MGs’) have commonly been made by quenching molten metal at a very high cooling rate. At present, interest in these materials is mainly fundamental, many computational simulations having been carried out. MAMs have desirable structure, strength, wear resistance and corrosion resistance together with unusual ductility but there are limited routes to their synthesis. Simpler, more versatile routes offering scope for surface modification and large scale processing are sought. Electrochemical routes offer exciting possibilities and a recent anodising route to nanospheres of tin or silver MAMs is profiled. Unusual features include the deposition of the desired metal at the anode surface of a cell with a controlled cell voltage and current in a glycerol/water/sodium nitrate electrolyte at room temperature (approx. 20°C). Further work on reaction environment and cell design in this emerging subject area might lead to a better understanding of the mechanism of particle formation together with a more general process route to synthesis of MAMs nanoparticles.

KEYWORDS:

• Anodising
• electrochemical techniques
• glassy metals
• MAMs
• hollow nanospheres
• metal ion reduction
• miniature metal particles
• nanoparticles

Disclosure statement

No potential conflict of interest was reported by the author(s).