A size-dependent structural evolution of ZnS nanoparticles

نویسندگان

  • Mohammad Khalkhali
  • Qingxia Liu
  • Hongbo Zeng
  • Hao Zhang
چکیده

Recently, ZnS quantum dots have attracted a lot of attention since they can be a suitable alternative for cadmium-based quantum dots, which are known to be highly carcinogenic for living systems. However, the structural stability of nanocrystalline ZnS seems to be a challenging issue since ZnS nanoparticles have the potential to undergo uncontrolled structural change at room temperature. Using the molecular dynamics technique, we have studied the structural evolution of 1 to 5 nm freestanding ZnS nanoparticles with zinc-blende and wurtzite crystal structures. Simulation results revealed that relaxed configurations of ZnS nanoparticles larger than 3 nm consist of three regions: a) a crystalline core, b) a distorted network of 4-coordinated atoms environing the crystalline core, and c) a surface structure made entirely of 3-coordinated atoms. Decreasing the size of ZnS nanoparticle to 2 nm will cause the crystalline core to disappear. Further reducing the size will cause all of the atoms to become 3-coordinated. Dipole moments of zinc-blende and wurtzite nanoparticles are in the same range when the nanoparticles are smaller than 3 nm. Increasing the size makes dipole moments converge to the bulk values. This makes zinc-blende and wurtzite nanoparticles less and more polar, respectively.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Structural, morphological and optical characterization of green synthesized ZnS nanoparticles using Azadirachta Indica (Neem) leaf extract

ZnS nanoparticles have been synthesized using various amounts of aqueous Azadirachta Indica (Neem) leaf extract as capping agent and stabilizer. The synthesized nanoparticles were studied by FTIR, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive analysis of X-rays (EDAX) and UV-Visible spectroscopy. FTIR spect...

متن کامل

Effect of Cationic Surfactant Head Groups on Synthesis, Growth and Agglomeration Behavior of ZnS Nanoparticles

Colloidal nanodispersions of ZnS have been prepared using aqueous micellar solution of two cationic surfactants of trimethylammonium/pyridinium series with different head groups i.e., cetyltrimethylammonium chloride (CTAC) and cetyltrimethylpyridinium chloride (CPyC). The role of these surfactants in controlling size, agglomeration behavior and photophysical properties of ZnS nanoparticles has ...

متن کامل

Evolution of ZnS Nanoparticles via Facile CTAB Aqueous Micellar Solution Route: A Study on Controlling Parameters

Synthesis of semiconductor nanoparticles with new photophysical properties is an area of special interest. Here, we report synthesis of ZnS nanoparticles in aqueous micellar solution of Cetyltrimethylammonium bromide (CTAB). The size of ZnS nanodispersions in aqueous micellar solution has been calculated using UV-vis spectroscopy, XRD, SAXS, and TEM measurements. The nanoparticles are found to ...

متن کامل

سنتز و بررسی خواص اپتیکی و ساختاری نانو ذره‌های پوسته/هسته ZnS/CdS

In this research, CdS nanoparticles and core/shell CdS/ZnS nanoparticles were prepared by using aqueous solution method and used 3-mercaptopropionic acid (MPA) as capping molecule. The effect of ZnS shell on optical and structural properties of CdS was investigated. X ray diffraction patterns of CdS nanoparticles at the room temperature and after heat treatment show zinc blende structure. X ray...

متن کامل

Preparation of ZnO and ZnS nanoparticles and in-vitro study of their antimicrobial effect

Zinc sulfide (ZnS) & zinc oxide (ZnO) nanoparticles was evaluated for their antimicrobial activity against four pathogenic strains. ZnS&ZnO nanoparticles were synthesized by simple aqueous chemical reaction in an aqueous solution. The main advantage of these nanoparticles (size of 10-30 nm) was that simply could be prepared by using cheap precursors in a cost effective and high throughput manne...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره 5  شماره 

صفحات  -

تاریخ انتشار 2015