Zhang Huiyun, Liu Guixian, Cao Yanqiang, Chen Jing, Shen Kai, Kumar Ashwini, Xu Mingxiang, Li Qi, Xu Qingyu
School of Physics, Southeast University, Nanjing 211189, China.
Phys Chem Chem Phys. 2017 Oct 11;19(39):26918-26925. doi: 10.1039/c7cp03470a.
Sulfur is easy to be incorporated into ZnO nanoparticles by the solution-combustion method. Herein, the magnetic and adsorption properties of a series of ZnOS (x = 0, 0.05, 0.1, 0.15, and 0.2) nanoparticles were systematically investigated. The X-ray diffraction patterns show that the as-prepared ZnOS nanoparticles have the hexagonal wurtzite structure of ZnO with a low sulfur content that gradually transforms into the zinc blende structure of ZnS when the x value is greater than 0.1. PL spectra show several bands due to different transitions, which have been explained by the recombination of free excitons or defect-induced transitions. The introduction of sulfur not only modifies the bandgap of ZnO, but also impacts the concentration of Zn vacancies. The as-prepared ZnO shows weak room-temperature ferromagnetism, and the incorporation of sulfur improves the ferromagnetism owing to the increased concentration of Zn vacancies, which may be stabilized by the doped sulfur ions. The adsorption capability of ZnOS nanoparticles has been significantly improved, and the process can be well described by the pseudo-first-order kinetic model and the Freundlich isotherm model. The mechanism has been confirmed to be due to the active sulfate groups existing in zinc oxysulfide nanoparticles.
通过溶液燃烧法，硫很容易掺入氧化锌纳米颗粒中。在此，系统研究了一系列ZnOS（x = 0、0.05、0.1、0.15和0.2）纳米颗粒的磁性和吸附性能。X射线衍射图谱表明，所制备的ZnOS纳米颗粒具有低硫含量的氧化锌六方纤锌矿结构，当x值大于0.1时，该结构逐渐转变为硫化锌的闪锌矿结构。PL光谱显示了由于不同跃迁产生的几个波段，这些已通过自由激子的复合或缺陷诱导跃迁得到解释。硫的引入不仅改变了氧化锌的带隙，还影响了锌空位的浓度。所制备的氧化锌表现出弱室温铁磁性，而硫的掺入由于锌空位浓度的增加而提高了铁磁性，掺杂的硫离子可能使其稳定。ZnOS纳米颗粒的吸附能力得到了显著提高，该过程可以用伪一级动力学模型和弗伦德里希等温线模型很好地描述。已证实其机理是由于氧硫化锌纳米颗粒中存在活性硫酸根。
