作者:Alex M. Wiltrout、Nathaniel J. Freymeyer、Tony Machani、Daniel P. Rossi、Katherine E. Plass
DOI:10.1039/c1jm13677a
日期:——
Nanoparticles of the copper iron sulfide phase bornite (ideally Cu5FeS4) have been synthesized phase selectively. Either the low or high bornite phase can be obtained through alteration of reactant ratios or reaction temperature, revealing a phase-selectivity that results from distinct rates of formation. The phase, shape, size, and composition of these novel nanomaterials are characterized by powder X-ray diffraction (PXRD), differential scanning calorimetry (DSC), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). The light absorption behaviour was investigated using ultra-violet/visible/near-infrared spectroscopy (UV/vis/NIR), revealing direct band gaps that are phase-dependent (low bornite, Eg = 0.86 eV and high bornite, Eg = 1.25 eV). The band gap exhibited by high bornite nanoparticles lies in the range of optimal solar energy conversion efficiency for a single-junction photovoltaic, making it a potentially useful light absorber consisting of inexpensive, abundant elements. Lastly, the selective formation of bornite nanoparticles, as opposed to the copper sulphides, chalcocite (Cu2S) and digenite (Cu1.80S), or chalcopyrite (CuFeS2) is demonstrated, suggesting solid solution formation between bornite and digenite nanoparticles.
铜铁硫化物相斑铜矿(理想情况下为 Cu5FeS4)纳米颗粒已被选择性合成。低斑铜体相或高斑铜体相都可以通过改变反应物比率或反应温度来获得,揭示了由不同的形成速率产生的相选择性。这些新型纳米材料的相、形状、尺寸和成分通过粉末 X 射线衍射 (PXRD)、差示扫描量热法 (DSC)、透射电子显微镜 (TEM) 和能量色散 X 射线光谱 (EDS) 进行表征。使用紫外/可见/近红外光谱 (UV/vis/NIR) 研究光吸收行为,揭示了与相位相关的直接带隙(低斑铜矿,Eg = 0.86 eV 和高斑铜矿,Eg = 1.25 eV) )。高斑铜矿纳米粒子表现出的带隙位于单结光伏发电的最佳太阳能转换效率范围内,使其成为由廉价、丰富的元素组成的潜在有用的光吸收剂。最后,证明了斑铜矿纳米颗粒的选择性形成,而不是硫化铜、辉铜矿 (Cu2S) 和二水铜矿 (Cu1.80S) 或黄铜矿 (CuFeS2),这表明斑铜矿和二水铜矿纳米粒子之间形成固溶体。