Assembling at the Nanoscale

This transmission electron micrograph showcases a curved chain of nine Zn-doped hollow MnO₂ nanospheres arranged in an almost serpentine “necklace” at 25,000× magnification (120 kV). Each sphere measures ~200 nm in diameter, confirmed by the 200 nm scale bar. The image clearly delineates the hollow cores (lighter regions) and crystalline shells (darker rims), with needle-like MnO₂ crystallites decorating the exterior — an effect enhanced by zinc incorporation during hydrothermal synthesis at 150°C for 48 hours using KMnO₄ and silica templates. The uniform particle size and striking self-assembly pattern highlight both precise nanoscale engineering and inherent aesthetic appeal.