One-step synthesis of water-soluble red AgInS2 nanocrystals with high photocatalytic hydrogen production activity

Abstract

The red water-soluble AgInS2 nanocrsytals (AIS NCs) were synthesized by one-step hydrothermal method. The effects of reaction time and molar ratio of precursors on the bandgap and fluorescence properties of AIS NCs were studied by UV–Vis absorption spectra, photoluminescence (PL) spectra. The experimental results indicated that the fluorescence peak of AIS NCs showed red-shift from 651 nm to 691 nm with the increase of reaction time. The full width at half maximum (FWHW) of AIS NCs obtained at 12 h was very narrow with 18.5 nm. When the reaction temperature and time were set to 200 °C and 12 h, the PL peaks of AIS NCs changed from 696 nm to 670 nm and 735 nm with the increase of indium concentration. In addition, the effect of In concentration on the optical band gap and PL peak was opposite. The optical bandgaps were 1.29 eV, 1.76 eV, and 1.51 eV, respectively. The photocatalytic H2 production performance was studied. The results indicated that the all AIS NCs obtained at different conditions showed high hydrogen production efficiency (>1000 μmol g−1•h−1). Finally, this method is very simple, safe, and easily controlled, and the position of fluorescence peak is adjustable, which shows that AIS NCs obtained in the paper have great application prospects.