Chemical Synthesis of ~1 nm Multilevel Capacitor-like Particles with Atomic Precision

Can the chemically synthesized nanoparticles act as nanodevices or nanomachines? Herein, we demonstrated this feasibility. A novel nanocluster (ultrasmall nanoparticle) [Au₄₄Cd₂₀(m-MBT)₄₀][N(C₈H₁₇)₄]₂ (Au₄₄Cd₂₀ in short, m-MBTH: m-methylbenzenethiol) obtained via developing a synthesis method has a cannula-like structure of the outer shell and an internal sleeve, revealed by single-crystal X-ray diffraction. Natural population analysis (NPA) charge calculations, charge carrier transport of Au₄₄Cd₂₀ (during which an intra-nanocluster anti-galvanic reaction was observed) after unneutral charging using NaBH₄ as well as voltammetry proved the capacitor-like character of Au₄₄Cd₂₀. The subsidiary capacitor-like character of the outer shell of Au₄₄Cd₂₀ was further probed via NPA charge calculations and electrocatalytic reduction of CO₂ to CO. Thus, this study predicts a new era of engineering metal nanoparticles for realizing atomically precise ultrasmall nanodevices and nanomachines.