The flask was then filled with nitrogen and heated to 270°C at a rate of 12°C · min-1 with magnetic stirring. After the reaction was allowed to proceed for 40 min, the reaction flask Blasticidin S nmr was naturally cooled to room temperature. The resulting CuGaS2 nanocrystals were collected by centrifugation and were washed thoroughly with toluene and ethanol. Finally, the purified nanocrystals were dried under vacuum for characterization.

Characterization The samples were characterized by powder X-ray diffraction (XRD) on a Philips X’pert X-ray diffractometer (Amsterdam, The Netherlands) equipped with Cu Kα radiation (λ =1.5418 Å). Tariquidar mw transmission electron microscope (TEM) images were taken with a Hitachi H-7650 microscope at an acceleration voltage of 100 kV. High-resolution transmission electron microscope (HRTEM) images were performed on a JEOL-2010 microscope (Akishima-shi, Japan). The scanning electron microscopy (SEM) images were taken using a Zeiss Supra 40 field emission scanning electron microscope (Oberkochen, Germany) operated at 5 kV. X-ray photoelectron spectra (XPS) were recorded on an ESCALab MKII X-ray photoelectron

spectrometer (VG Scienta, Newburyport, MA, USA). The UV–vis absorption spectra were recorded CX-6258 price on a Solid Spec-3700 spectrophotometer. Results and discussion Figure 1 shows the powder XRD pattern of the as-synthesized product. Generally, CuGaS2 (CGS) crystallizes in thermodynamically stable tetragonal chalcopyrite structure, in which Cu and Ga ions are ordered in the cation sublattice sites (Additional file 1: Figure S1a). Meanwhile,

two cation-disordered structures, i.e. cubic zincblende modification (Additional file 1: Figure S1b) and hexagonal wurtzite phase (Additional file 1: Figure S1c), can be constructed for CGS [21]. The present XRD pattern was characteristic of a hexagonal wurtzite structure. In addition, a weak reflection peak at 2θ = 33.7° was found in the present XRD pattern, which was indexed to (200) of cubic zincblende CGS. Thus, the obtained product also contains Linifanib (ABT-869) cubic zincblende CGS. No characteristic peaks of other impurities such as copper or indium sulfides were observed, which indicates that the as-synthesized product is composed of pure ternary CGS. To determine the lattice parameters and proportions of wurtzite and zincblende structures in the as-synthesized product, the present XRD pattern was well fitted by using Rietveld refinement analysis performed with MAUD program [22]. It is determined that the product consists of approximately 60% hexagonal wurtzite CGS (P63 mc, a = 3.727(5) Å, c = 6.197(6) Å) and 40% cubic zincblende CGS (F-43 m, a = 5.309(0) Å). Figure 1 Powder XRD pattern of as-synthesized product. The experimental data (dots), a Rietveld fit (red line, Rwp 3.57%, Rp 2.70%), reflection positions of wurtzite (top row) and zincblende (bottom row) CuGaS2, and the different curves are displayed.