Magnetic Separation of Oxoacid of Boron from Salt-Lake Brine by Synergistically Enhanced Boron Adsorbents of Glucose-Functionalized SiO2 and Graphene.

The adsorption separation and extraction of low-concentration boron from salt-lake brine have great significance. Magnetic separation avoids the problem of adsorbent granulation and improves the usage efficiency. The silicon-based adsorbents have attracted interest due to their superior acid and alkali resistance, in which polyhydroxy graphene enhances the adsorption of boron ions. Herein different boron adsorbents, derived by magnetic separation, were developed and characterized by SEM, TEM, XPS, VSM, FT-IR, and XRD analysis. The adsorption-desorption performance of boron adsorbents with different compositions was evaluated. The isotherms and kinetics parameters of the boron extraction were evaluated based on adsorption-desorption tests. The graphene-based magnetic adsorbent (Go-Fe3O4@SiO2@mSiO2-Glu) registered a high boron adsorption capacity of 23.90 mg/g at pH = 9 in the boron solution and 24.84 mg/g for East Taigener salt-lake brine. The Na+, Mg2+, Ca2+, and Cl- ions have little interference with the boron adsorption. The adsorbents exhibit magnetic separation performance and good cycle life. The results showed that acid-alkali desorption solution has little effect on the adsorbents, and the composite of graphene enhances the adsorption of boron ions. The adsorbents developed in this study are promising to recover boron from low-concentration boron-containing salt-lake brines.

Synthesis, Characterization and Luminescent Properties of Anthracen- or Pyrene-Based Coumarin Derivatives.

Three anthracen- or pyrene-based coumarin derivatives have been successfully synthesized and characterized by EA, IR and 1H NMR. The photophysical properties of all derivatives were investigated by UV-Vis and photoluminescence spectroscopic analysis. Their thermal stabilities were demonstrated by TGA. These compounds exhibit strong blue mission under ultraviolet light excitation and have potential possible to explore organic electroluminescent materials. The vacuum-processed doped devices with a configuration of ITO/TAPC (20 nm)/TBADN: b1 (x wt%, 30 nm)/TPBi (50 nm)/Liq (2 nm)/Al (150 nm) was fabricated, in which the devices based on b1 exhibited the best electroluminescence performance with a maximum brightness of 8165 cd/m2 and a maximum luminous efficiencies of 6.13 cd/A and a maximum external quantum efficiency (EQE) of 2.75%.

Recovery of metal ion resources from waste lithium batteries by in situ electro-leaching coupled with electrochemically switched ion exchange.

A new green pathway of in situ electro-leaching coupled with electrochemically switched ion exchange (EL-ESIX) technology was developed for the separation and recovery of valuable metal ions from waste lithium batteries. By using the in situ electro-leaching, the leaching rates of Li+ and Co2+ from the prepared LiCoO2 film electrodes reached 100 % and 93.30 %, respectively, under the combined effect of the acidic microenvironment formed by the anodic electrolytic water and electrostatic repulsion. Subsequently, the Li+ in the electrolyte was further extracted by an electrochemically switched ion exchange (ESIX) process using LiMn2O4 as the film electrode, and Li+ was further enriched in the eluate by a cyclic adsorption and desorption process. The results indicate that the in situ electro-leaching has significant advantages over powder leaching, and for the recycling of waste lithium batteries, the final lithium recovery rate reached 94.51 % by using this in situ EL-ESIX technology.

Cyclodextrin derivatives used for the separation of boron and the removal of organic pollutants.

Adsorption plays an important role in seawater desalination, wastewater treatment, and, especially, boron removal from natural aqueous systems. In this paper, two sponge-like multifunctional polymers based on a cyclodextrin backbone were synthesized and used as adsorbents for the removal of boron, methylene blue (MB), methyl orange (MO), and phenol. The syntheses were carried out by esterification, atom transfer polymerization, and nucleophilic addition reaction. The polymers were characterized by 1H NMR spectroscopy, IR spectroscopy, XRD, XPS, and SEM. The performance of the two different adsorbents was investigated considering the effect of pH, initial concentration, and the anions and cations in an aqueous solution of borates. The experimental data were fitted with an adsorption isothermal model, adsorption kinetic model and other models. Both adsorbents exhibited high adsorption capacities (B: 31.05 mg/g and 20.45 mg/g, MB: 29.43 mg/g and 32.29 mg/g, MO: 47.36 mg/g and 49.23 mg/g, phenol: 5.04 mg/g and 4.35 mg/g, respectively) and a fast adsorption rate. The boron adsorption was found to be an exothermic process. The adsorbents show promising potential for the removal of boron and benzene-containing organic pollutants from aqueous solution.

DFT calculation of hydrothermal mechanism on preparation of MoS2.

Basing on the simplest hydrothermal system containing deionized water, hexa-ammonium molybdate, and thiourea, hydrothermal mechanism on preparation of MoS2 was studied by DFT calculation. Hydrothermal process was divided into four steps which covered ionization equilibrium, the hydrolysis of CS(NH2)2, the formation of intermediates, and the formation of MoS2. Ionization equilibrium occurs at normal condition and determines the existence of Mo in the form of molybdic acid. Thiourea hydrolysis is rate-determining step in the process of hydrothermal which contains 10 elementary reactions. The formation of intermediates includes hydrogen transfer, dehydration, and vulcanization three steps which contain 18 elementary reactions, and the energy barrier of vulcanization is the highest. The formation of MoS2 is divided into two steps, the first step is that MoO(OH)(SH)3.H2O reacts with MoO (SH)4.H2O to form layer MoS2, and the second step is a very fast process that can affect the morphology of the products.