One-step synthesis of photoluminescent catalytic gold nanoclusters using organoselenium compounds

Abstract

In this study, a facile and rapid method was developed to synthesize intensely photoluminescent catalytic gold nanoclusters (AuNCs) based on etching small citrate-capped gold nanoparticles using 4,6-dimethyl-2-pyridineselenol-3-caronitrile as a model for organoselenium compounds. The size and catalytic performance of the as-prepared fluorescent nanoclusters were characterized using suitable transmission electron microscopy (TEM), atomic force microscopy (AFM), electrospray ionization-mass spectrometry (ESI-MS) and photoluminescence techniques. It was shown that Au clusters with an average gold core diameter of 0.78 ± 0.41 nm (in the range of 5–9 atoms) play a catalytic role in the directed growth of gold nanorods with high aspect ratios (a.r. = 18–23). Methylene blue dye was photodegraded by these photo-responsive gold clusters under UV light (within 40 minutes) and under visible light (within 120 minutes). Furthermore, we demonstrated that the formed nanoclusters display excellent catalytic activity in the photoreduction of toxic compounds, i.e., in the conversion of 4-nitrophenol to 4-aminophenol with high yield (83%) and short reaction time.