FeCl2-assisted synthesis and photoluminescence of β-SiC nanowires

Abstract

β-SiC nanowires were synthesized by the carbothermal reduction of the carbonaceous silica xerogel prepared using tetraethoxysilane (TEOS) and sucrose as sources, and ferrous chloride as an additive. The products were obtained by heating the xerogel at 1300°C for 6h in argon flow (200ml/min). The products were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), scanning electron microscope (SEM), high-resolution transmission electron microscope (HRTEM), energy-dispersive X-ray spectroscopy (EDS), and selected area electron diffraction (SAED). The results show that the products mainly consist of crystalline β-SiC nanowires with an amorphous SiO2 shell. The SiC nanowires have a diameter of 100–300nm and a length from tens to hundreds of micrometers. The vapor–liquid–solid (VLS) mechanism was proposed to explain the formation of β-SiC nanowires, and the nanowires mainly grow along [111] direction. The photoluminescence (PL) spectrum of β-SiC nanowires at room temperature shows two emission peaks at 405nm and 436nm.