Search Results (2)

A variety of chemical sensing materials and procedures for conveniently detecting mercuric ion (II) (Hg²⁺) have been extensively explored. The detection challenges for accomplishing a simple, fast, and low investment procedure at the ultrasensitive level are ongoing. Herein we report a quadrillionth level for detecting Hg²⁺ by the surface-enhanced Raman scattering (SERS) technique. There is an interaction of silver nanoparticles decorated on a zinc-oxide tetrapod structure and coated on FTO glass (Ag@ZnO-FTO) with an organic ligand. 4,4′-Dipyridyl (DPy) performed as being chemisorbed by Ag nanoparticles interacting with a pyridine ring to produce plasmonic hot spots for SERS. The morphology of the surface and porous structure of the tetrapod becomes the powerful platform for enhanced SERS performance of DPy detection. In the absence of the augmentative electrolyte, the enhancement factor for DPy is more than 10⁷. The inhibiting of the aggregation between Ag and DPy was present following the appearance of Hg²⁺, demonstrated by the quenching of the SERS signal from the DPy molecules. The capability to reproduce and the selectivity of the sensing by DPy were both demonstrated. In addition, the applications for detecting Hg²⁺ in natural water and beverages were successfully detected. These results demonstrated the SERS sensors had the potential for detecting Hg²⁺ in practical use. Full article

Copper ferrite nano-particles (CuFe₂O₄) were synthesized, characterized, modified with polyaniline to form CuFe₂O₄/PANI nano-composite. They were used as new adsorbents for the removal of the hazardous mercuric ions from aqueous solutions. High resolution transmission electron microscope (HR-TEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) and Brunauer–Emmett–Teller (BET) were used for the characterization of the synthesized CuFe₂O₄ nano-particles (NPs) in presence and absence of PANI nano-composite. The synthesized CuFe₂O₄NPs were of spherical shape with an average size of 10.8 nm. XRD analysis displayed crystal peaks for CuFe₂O₄NPs and amorphous peaks CuFe₂O₄/PANI nano-composite due to the existence of polyaniline layer. Contact time, adsorbent dose, solution pH, adsorption kinetics, adsorption isotherm and recyclability were studied. The method at the optimum conditions exhibited high performance with high mercury removal percentage of up to 99% with a maximum adsorption capacity 12.5 and 157.1 mg/g for CuFe₂O₄ and CuFe₂O₄/PANI, respectively. The adsorption processes were fitted to Langmuir isotherms. The adsorption behavior of CuFe₂O₄@PANI composite towards Hg²⁺ ions is attributed to the soft acid–soft base strong interaction between PANI and Hg(II) ions. High stability and enhanced re-usability are offered using CuFe₂O₄@PANI composite due to its enhanced removal efficiency. No significant removal decrease was noticed after five adsorption–desorption cycles. In addition, it possesses an easy removal from aqueous solutions by external magnetic field after adsorption experiments. These indicated the enhancement of polyaniline to the surface of CuFe₂O₄ toward the adsorption of mercury from aqueous solutions. Full article