General Route to the Fabrication of ZnS and M-Doped (M = Cd2+, Mn2+, Co2+, Ni2+, and Eu3+) ZnS Nanoclews and a Study of Their Properties

Facile one-pot sonochemical synthesis of Ni doped bismuth sulphide for the electrochemical determination of promethazine hydrochloride

The present work reports the facile and cost-effective synthesis of rod like structured nickel doped bismuth sulphide (Ni-Bi₂S₃) via the ultrasonication process. The sonochemical synthesis technique is rapid, simple, non-explosive, and harmless than other conventional synthesis technique. After the synthesis, the resultant material was characterized through the various spectrophotometric techniques including FESEM, EDX, XRD, XPS and EIS. After the structural evaluation, as-synthesized Ni-Bi₂S₃ was applied for the electrocatalytic detection of promethazine hydrochloride (PMTZ) using CV and amperometry (i-t) techniques. Captivatingly, excellent electrocatalytic performance with the wider linear range from 1 nM to 163.17 µM was obtained for the electrochemical determination of PMTZ. The limit of detection (LOD) and sensitivity calculated around 0.4 nM and 2.904 μA µM^-1 cm^-2, respectively. Besides, an excellent selectivity, satisfactory reproducibility and good stability of the Ni-Bi₂S₃ modified electrode were checked towards the electrochemical determination of PMTZ. Furthermore, the real time application of PMTZ sensor was established in human serum and urine samples.

Capping ligand infrared absorption and dopant photoluminescence spectroscopy provides a comprehensive picture to probe dopant spatial location in semiconductor nanoparticles

A room temperature based spectroscopic analysis technique assesses the luminescence properties from different spatial location of lanthanide cations in zinc sulfide nanoparticles.

Gas Sensors Based on Metal Sulfide Zn(1-x)Cd(x)S Nanowires with Excellent Performance

Metal sulfide Zn1-xCdxS nanowires (NWs) covering the entire compositional range prepared by one step solvothermal method were used to fabricate gas sensors. This is the first time for ternary metal sulfide nanostructures to be used in the field of gas sensing. Surprisingly, the sensors based on Zn1-xCdxS nanowires were found to exhibit enhanced response to ethanol compared to those of binary CdS and ZnS NWs. Especially for the sensor based on the Zn1-xCdxS (x = 0.4) NWs, a large sensor response (s = 12.8) and a quick rise time (2 s) and recovery time (1 s) were observed at 206 °C toward 20 ppm ethanol, showing preferred selectivity. A dynamic equilibrium mechanism of oxygen molecules absorption process and carrier intensity change in the NWs was used to explain the higher response of Zn1-xCdxS. The reason for the much quicker response and recovery speed of the Zn1-xCdxS NWs than those of the binary ZnS NWs was also discussed. These results demonstrated that the growth of metal sulfide Zn1-xCdxS nanostructures can be utilized to develop gas sensors with high performance.

Lanthanide cation-induced tuning of surface capping properties in zinc sulfide nanoparticles: an infrared absorption study

Lanthanide cations tune the infrared absorption characteristics of the capping ligands in Zn(Ln)S [Ln = Sm, Eu, Tb, Dy] nanoparticles.

A Post-synthetic Modification of II-VI Nanoparticles to Create Tb3+ and Eu3+ Luminophores

We describe a novel method for creating luminescent lanthanide-containing nanoparticles in which the lanthanide cations are sensitized by the semiconductor nanoparticle's electronic excitation. In contrast to previous strategies, this new approach creates such materials by addition of external salt to a solution of fully formed nanoparticles. We demonstrate this post-synthetic modification for the lanthanide luminescence sensitization of two visible emitting lanthanides (Ln), Tb³⁺ and Eu³⁺ ions, through ZnS nanoparticles in which the cations were added post-synthetically as external Ln(NO₃)₃·xH₂O salt to solutions of ZnS nanoparticles. The post-synthetically treated ZnS nanoparticle systems display Tb³⁺ and Eu³⁺ luminescence intensities that are comparable to those of doped Zn(Ln)S nanoparticles, which we reported previously (J. Phys. Chem. A, 2011, 115, 4031-4041). A comparison with the synthetically doped systems is used to contrast the spatial distribution of the lanthanide ions, bulk versus surface localized. The post-synthetic strategy described in this work is fundamentally different from the synthetic incorporation (doping) approach and offers a rapid and less synthetically demanding protocol for Tb³⁺:ZnS and Eu³⁺:ZnS luminophores, thereby facilitating their use in a broad range of applications.

One-pot synthesis of CdS and Ni-doped CdS hollow spheres with enhanced photocatalytic activity and durability

CdS and Ni-doped CdS hollow spheres were synthesized via a simple template-free one-pot method. The products were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, energy-dispersive spectroscopy analysis, X-ray photoelectron spectroscopy, and UV-vis absorption spectroscopy. The formation mechanism for the Ni-doped CdS hollow spheres was discussed. The prepared CdS and Ni-doped CdS hollow spheres showed the superior photocatalytic activity for the degradation of RhB under visible light (λ > 420 nm) irradiation, and 1.2 mol % Ni-doped CdS hollow spheres were found to be highly efficient for organic pollutants RhB and phenol removal. Moreover, this catalyst showed improved stability, and the activity did not decrease significantly after four recycles. The unique hollow spheres structure may favor the harvesting of exciting light due to multiple scattering within the interior space, and the doping of Ni(2+) may facilitate the generation of electrons and holes pairs and inhibit their recombination rate by act as a temporary trapping sites of photoinduced electrons.

Lanthanide sensitization in II-VI semiconductor materials: a case study with terbium(III) and europium(III) in zinc sulfide nanoparticles

This work explores the sensitization of luminescent lanthanide Tb(3+) and Eu(3+) cations by the electronic structure of zinc sulfide (ZnS) semiconductor nanoparticles. Excitation spectra collected while monitoring the lanthanide emission bands reveal that the ZnS nanoparticles act as an antenna for the sensitization of Tb(3+) and Eu(3+). The mechanism of lanthanide ion luminescence sensitization is rationalized in terms of an energy and charge transfer between trap sites and is based on a semiempirical model, proposed by Dorenbos and co-workers (Dorenbos, P. J. Phys.: Condens. Matter 2003, 15, 8417-8434; J. Lumin. 2004, 108, 301-305; J. Lumin. 2005, 111, 89-104. Dorenbos, P.; van der Kolk, E. Appl. Phys. Lett. 2006, 89, 061122-1-061122-3; Opt. Mater. 2008, 30, 1052-1057. Dorenbos, P. J. Alloys Compd. 2009, 488, 568-573; references 1-6.) to describe the energy level scheme. This model implies that the mechanisms of luminescence sensitization of Tb(3+) and Eu(3+) in ZnS nanoparticles are different; namely, Tb(3+) acts as a hole trap, whereas Eu(3+) acts as an electron trap. Further testing of this model is made by extending the studies from ZnS nanoparticles to other II-VI semiconductor materials; namely, CdSe, CdS, and ZnSe.