Absorption of Iodide Ions in Aqueous Solution by ZIF-67 and ZIF-8

Two zeolite-like imidazate metal-framework materials ZIF-67 and ZIF-8 were synthesized by using Co(NO_(3))2,Zn(NO_(3))_(2),2-methyl imidazole and methanol as raw materials,and these two materials were used to adsorb iodine ions in water.The impact of pH,contact time and temperature etc.on the adsorption capability of iodide ions in aqueous solutions by the two ZIF materials was investigated.The results show that the optimal adsorption pH was 7,and the optimal adsorption time was 18 h.The adsorption of iodide ions by ZIF-67 was consistent with the Langmuir adsorption isotherm,while the absorption of iodide ions by ZIF-8 was in better consistency with the Freundlich adsorption isotherm.The maximum adsorption capacity of iodide ions by ZIF-67 and ZIF-8 was 141.81 and 474.02 mg/g respectively.The adsorption of iodide ions by the two materials was more in line with the quasi-first-order kinetic model,and the adsorption was monolayer adsorption.

Electrodeposited iodide ions imprinted polypyrrole@bismuth oxyiodide film for an electrochemically switched renewable extractor towards iodide ions

Effective extraction and regeneration of radioactive iodide is one of urgent concerns for the safe utilization of nuclear energy.As a novel environmentally benign ion separation technique,electrochemically switched ion extraction(ESIE)process can be applied for effective capture and recovery of iodide ions(I^(-)).Herein,a novel kelp seaweed-like core/shell I^(-)imprinted polypyrrole@bismuth oxyiodide(PPy/I^(-)@BiOI)composite film is successfully prepared for the selective I^(-)capture in the ESIE system.It is found that the I^(-)can be easily trapped in the PPy/I^(-)@BiOI film after I^(-)is in situ desorbed from the film by an electrochemical reduction process since it offers particular electroactive binding sites for I^(-)extraction.The I^(-)imprinted PPy/I^(-)@BiOI film displays an extraction capacity as high as 325.2 mg·g^(-1)for I^(-)with favorable stability.In particular,the extraction and desorption of I^(-)is achieved by adjusting the redox potential and the pristine PPy/I^(-)@BiOI film can be regenerated and reused for multiple times without decrease in extraction capacity.It is expected that such a PPy/I^(-)@BiOI film would be useful as an electrochemically switched renewable extractor that could capture and regenerate I^(-)from radioactive water.

Facile synthesis of gold nanoflowers as SERS substrates and their morphological transformation induced by iodide ions

We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal enhancement. We further found that iodide ions （I^-） could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance （LSPR） bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I^-.

Synergistic inhibitive effect of cysteine and iodide ions on corrosion behavior of copper in acidic sulfate solution

The synergistic inhibitive effect of cysteine(Cys)and iodide ions on the corrosion behavior of copper was examined in a 0.5 mol·L^(-1) Na_(2)SO_(4) solution.Potentiodynamic polarization curve revealed that Cys acted as a mixed type inhibitor with a major effect on the cathodic process,consequently decreased the corrosion current density by a great extent and shifted the corrosion potential negatively.The investigated results suggested that iodide ions can enhance the inhibition efficiency of Cys.The inhibition mechanism of Cys and the synergistic effect of the two examined reagents were investigated by fitting experimental impedance data according to a projected equivalent circuit for metal/electrolyte interface.Surface analysis further confirmed that the corrosion inhibition was realized due to the adsorption of the inhibitor molecules at the metal/solution interface.Langmuir adsorption isotherm was proposed to describe inhibition mechanism of Cys on copper surface.Active sites of Cys molecule were used to form inhibitor film on the copper surface.Addition of iodide ion increased its inhibition efficiency by enhancing adsorption of Cys cations through electrostatic interaction with I-pre-adsorbed on Cu surface.

Colorimetric and Photothermal Dual-modal Visual Detection of Iodide Ion Based on G-Quadruplex-Hemin Cascade Signal Amplification

The insufficient internal resorption of iodide ions(I−)leads to thyroid disorders,such as goiter,hypothyroidism,and cretinism in adults.In this paper,a portable point-of-care testing(POCT)platform was developed for the dual-modal analysis of I^(−),seamlessly integrating both colorimetric and photothermal thermometer techniques.The quantification of results was achieved using a standard thermometer or smartphone.G-Quadruplex/Hemin(G4/Hemin)is the DNAzyme with peroxidase-like activity.The catalytic efficacy of G-quadruplex structures can be enhanced with the help of I^(−),manifesting as multicolor transitions from colorless to green and then blue,and accompanied by the increase of temperature,which can be used for the quantitative detection of I^(−).Additionally,digital analysis according to the three-color channels(R/G/B)by a cellphone eliminated the requirement for intricate instruments.This dual-modal method for portable I^(−)determination is cost-effectiveness,simplicity,remarkable sensitivity(0.5 nmol/L)and selectivity.Besides,it was applied to determining the concentration of I^(−)in spiked serum samples.