High-performance and good-stability hollow Sn-based perovskite solar cells using ethylenediammonium and formamidinium cations.

Uranium is important in the nuclear fuel cycle both as an energy source and as radioactive waste. It is of vital importance to recover uranium from nuclear waste solutions for further treatment and disposal. Herein we present the first chalcogenide example, (Me2NH2)1.33(Me3NH)0.67Sn3S7·1.25H2O (FJSM-SnS), in which organic amine cations can be used for selective UO2(2+) ion-exchange. The UO2(2+)-exchange kinetics perfectly conforms to pseudo-second-order reaction, which is observed for the first time in a chalcogenide ion-exchanger. This reveals the chemical adsorption process and its ion-exchange mechanism. FJSM-SnS has excellent pH stability in both strongly acidic and basic environments (pH = 2.1-11), with a maximum uranium-exchange capacity of 338.43 mg/g. It can efficiently capture UO2(2+) ions in the presence of high concentrations of Na(+), Ca(2+), or HCO3(-) (the highest distribution coefficient Kd value reached 4.28 × 10(4) mL/g). The material is also very effective in removing of trace levels of U in the presence of excess Na(+) (the relative amounts of U removed are close to 100%). The UO2(2+)···S(2-) interactions are the basis for the high selectivity. Importantly, the uranyl ion in the exchanged products could be easily eluted with an environmentally friendly method, by treating the UO2(2+)-laden materials with a concentrated KCl solution. These advantages coupled with the very high loading capacity, low cost, environmentally friendly nature, and facile synthesis make FJSM-SnS a new promising remediation material for removal of radioactive U from nuclear waste solutions.

Iodine ( 129 I and 131 I) is one of the radionuclides released in nuclear fuel reprocessing and poses a risk to public safety due to its involvement in human metabolic processes. In order to prevent the release of hazardous radioactive iodine into the environment, its effective capture and sequestration is pivotal. In the context of finding a suitable matrix for capturing radioactive iodine, several sulfidic chalcogels were explored as iodine sorbents including NiMoS 4 , CoMoS 4 , Sb 4 Sn 3 S 12 , Zn 2 Sn 2 S 6 , and K 0.16 CoS x (x = 4−5). All of the chalcogels showed high uptake, reaching up to 225 mass % (2.25 g/g) of the final mass owing to strong chemical and physical iodine−sulfide interactions. Analysis of the iodine-loaded specimens revealed that the iodine chemically reacted with Sb 4 Sn 3 S 12 , Zn 2 Sn 2 S 6 , and K 0.16 CoS x to form the metal complexes SbI 3 , SnI 4 , and, KI, respectively. The NiMoS 4 and CoMoS 4 chalcogels did not appear to undergo a chemical reaction with iodine since iodide complexes were not observed with these samples. Once heated, the iodine-loaded chalcogels released iodine in the temperature range of 75 to 220 °C, depending on the nature of iodine speciation. In the case of Sb 4 Sn 3 S 12 and Zn 2 Sn 2 S 6 , iodine release was observed around 150 °C mainly in the form of SnI 4 and SbI 3 , respectively. The NiMoS 4 , CoMoS 4 , and K 0.16 CoS x released elemental iodine at ∼75 °C, which is consistent with physisorption. Preliminary investigations on consolidation of iodine-loaded Zn 2 Sn 2 S 6 chalcogel with Sb 2 S 3 as a glass forming additive produced glassy material whose iodine content was around 25 mass %.

We report the synthesis of ion-exchangeable molybdenum sulfide chalcogel through an oxidative coupling process, using (NH4)2MoS4 and iodine. After supercritical drying, the MoS(x) amorphous aerogel shows a large surface area up to 370 m(2)/g with a broad range of pore sizes. X-ray photoelectron spectroscopic and pair distribution function analyses reveal that Mo(6+) species undergo reduction during network assembly to produce Mo(4+)-containing species where the chalcogel network consists of [Mo3S13] building blocks comprising triangular Mo metal clusters and S2(2-) units. The optical band gap of the brown-black chalcogel is ∼1.36 eV. The ammonium sites present in the molybdenum sulfide chalcogel network are ion-exchangeable with K(+) and Cs(+) ions. The molybdenum sulfide aerogel exhibits high adsorption selectivities for CO2 and C2H6 over H2 and CH4. The aerogel also possesses high affinity for iodine and mercury.

Unconventional ion exchangers can achieve efficient removal of [UO], Cs, and Sr ions from complex aqueous solutions and are of great interest for environmental remediation. We report two new gallium thioantimonates, [MeNH][GaSbS]·HO (FJSM-GAS-1) and [EtNH][GaSbS]·HO (FJSM-GAS-2), which present excellent ion exchange properties for [UO], Cs, and Sr ions. They exhibit high ion exchange capacities for [UO], Cs, and Sr ions ( q = 196 mg/g, q = 164 mg/g, and q = 80 mg/g for FJSM-GAS-1, q = 144 mg/g for FJSM-GAS-2) and short equilibrium times for [UO] ion exchange (5 min for FJSM-GAS-1 and 15 min for FJSM-GAS-2, respectively). Both compounds display active ion exchange with [UO] in the pH range of 2.9-10.5. Moreover, the sulfide compounds could maintain high distribution coefficients K even in the presence of excess Na, Ca, and HCO. The distribution coefficient K of 6.06 × 10 mL/g exhibited by FJSM-GAS-1 is the highest among the reported U adsorbents. The [UO]-laden products can be recycled by conveniently eluting the uranium with a low-cost method. These advantages combined with facile synthesis, as well as β and γ radiation resistance, make FJSM-GAS-1 and FJSM-GAS-2 promising for selective separations in nuclear waste remediation.

A new microporous Zr4+ MOF combines both extraordinary sorption capability and exceptional luminescence sensing properties for Cr(vi) in aqueous media.

An ion-exchange column of metal organic resin (MOR-1)–alginic acid (HA) composite shows remarkable efficiency and selectivity for sorption of Cr(vi).

The synthesis and crystal structure of K2xSn4–xS8–x (x = 0.65–1, KTS-3) a material which exhibits excellent Cs+, Sr2+ and UO22+ ion exchange properties in varying conditions are reported.