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Complexant-montmorillonite nanocomposites were successfully prepared through the intercalation of the complexants cysteamine hydrochloride (CSH), 1,6-diaminlhexane (DA), tetraethylenepentamine (TEPA) with different functional group and molecular weight in this work. More importantly, it was proved that the heavy metal stabilization property of montmorillonite improved significantly after intercalation of complexants through characterization by XRD and SEM-EDS. Here, the complexant-montmorillonite nanocomposites exhibited strong pH buffering effects. The Zn stabilization rate was prone to 100% by adding DA or TEPA modified montmorillonite (DA-Mt or TEPA-Mt) into the tailings, and the releasing rate of As and Mn from tailings also decreased greatly. Generally, the Zn, Pb, Mn and As stabilization effects of both TEPA-Mt and DA-Mt were much better than that of CSH modified montmorillonite, which suggested that the heavy metal complexing abilities of complexant-montmorillonite nanocomposites highly depended on the functional group and molecular weight of the complexants. In this study, electrostatic adsorption, physical adsorption, ion exchange and complexation worked together and produced good heavy metal stabilization effect. Our findings could provide an important reference for the synthesis of efficient stabilization nanomaterials.

Solvent-impregnated resins (CA−12/SIRs) have been prepared by using amidoxime resin waste as a polymeric support. The process of gallium (Ga) adsorption onto CA− 12/SIRs from a hydrochloric acid solution was examined in a batch experiment. It was found that CA− 12/SIRs exhibits excellent adsorbent properties with a saturated adsorption capacity of up to 31.2 mg·g−1(318 K). In addition, CA− 12/SIRs showed an outstanding separation ability for Ga(Ⅲ), with a partition coefficient as high as above 2500 mL·g−1. The optimum pH value was found to be 2.75. Moreover, CA− 12/SIRs maintained an excellent adsorption performance for Ga(III), even after ten adsorption-elution cycles. For practical applications, the adsorption percentage of Ga(III) onto CA− 12/SIRs reached more than 99 % when using hydrochloric acid and sulfuric acid solutions. Thus, a low-cost adsorbent has been developed in the present study by which it is possible to purify gallium. Moreover, this study has provided a new direction for also other types of waste resins in the preparation of impregnated resins.

In this investigation, to separate and recover indium (In), the adsorption and desorption characteristics of indium in the sulfite-sulfuric acid system using IRA-900 resin and the adsorption mechanism were explored. When sodium sulfite and sulfuric acid concentrations were 0.5 mol/L, IRA-900 resin exhibited the best adsorption selectivity to indium, with an adsorption capacity of 95.56 mg/g(318 K), while the adsorption capacities of Al, Sr, Fe, Zn and Cu were weak. In(Ⅲ) adsorption by resin conforms to the second-order kinetic model, and the Langmuir model is more suitable for adsorption. In desorption experiments, 2 mol/L hydrochloric acid was selected as the desorption agent, with a desorption rate of 82.39 %. FT-IR (Fourier-transform infrared spectroscopy), SEM-EDS (Scanning electron microscopy with energy dispersive spectroscopy), XPS (X-ray photoelectron spectroscopy) and elemental analysis results indicated that the adsorption mechanism of indium could be attributed to the formation of an anionic complex between In3+and HSO3-/HSO4-, which could be exchanged with Cl-on the resin to adsorb the metal ions. In addition, the column experiment could efficiently separate indium from simulated indium-containing solution. In(Ⅲ) recovery yield was about 99.6%, indicating its effective separation and recovery from ITO (Indium tin oxide) film.

Metal phosphides are of great recent interest as promoters to precious metal-driven catalytic oxidation of alcohols in direct alcohol fuel cells. In this work, a novel approach for facile and environmentally friendly synthesis of molybdenum phosphide (MoP) nanocrystals anchored on graphitized carbon is developed by one-step pyrolysis of a phosphorus-containing resin exchanged with Mo5+. A significant promotion effect of MoP on Pt in methanol electrooxidation is observed. The Pt–MoP/C catalyst exhibits ultrahigh electroactivity, and compared to commercial Pt/C, this catalyst reaches a −140 mV more negative onset potential and has 10 times the mass activity at 0.4 V vs.SCE and 5.1 times the peak mass activity. In addition, Pt–MoP/C has also excellent stability and CO tolerance, including a peak mass activity retention of 81.4% after 1000 cycles as compared to that of 51.6% on commercial Pt/C and a 140 mV more negative COadoxidation potential. The noteworthy promotion effect of MoP on Pt in methanol electrooxidation is also evaluated by theoretical calculations.