•Rice-shaped Ag2S nanoparticles have been synthesized via a hydrothermal route.•Pyrrolidone rings of the PVP were involved in the morphology shaping process.•Ammonia complexation showed deep impacts on morphology control.•Tip part of the Ag2S nanorice could result in quantum confinement effects.Silver sulfide (Ag2S) nanorice was synthesized by reaction between silver ammonia complex cation ([Ag(NH3)2]+) and sodium sulfide nonahydrate (Na2S·9H2O) in the presence of polyvinylpyrrolidone (PVP) through a hydrothermal method. The obtained products were characterized by X-ray powder diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FT-IR), ultraviolet–visible spectroscopy (UV–vis) and transmission electron microscopy (TEM). It was found that the as-prepared Ag2S nanocrystal was monoclinic, and the formation of the rice-shaped feature depended mainly on the type of silver source, influence of the pyrrolidone rings of the PVP, reaction time and temperature. Both the remarkable blue shift and the large band gap energy of 4.4 eV revealed that the tip part of the as-prepared Ag2S nanorice could result in quantum confinement effect.

Silver nanorods have been successfully synthesized via a facile route using sodium tripolyphosphate (Na5P3O10) as the capping agent. Silver nitrate and glucose served as the Ag+ source and green reducing agent in aqueous solution, respectively. The products were characterized by X-ray powder diffraction (XRD), UV–visible spectroscopy (UV–vis), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). The results showed that the obtained silver nanorods are highly crystallized with an average diameter of 30 nm and lengths up to 400 nm. The linear structure of the capping agent and slow reaction rate are considered to be key factors in the control of particle morphology. The possible formation mechanism has been discussed based on the experimental results.