Crystal Structure, Vibrational, Spectroscopic and Thermochemical Properties of Double Sulfate Crystalline Hydrate [CsEu(H2O)3(SO4)2]·H2O and Its Thermal Dehydration Product CsEu(SO4)2

Crystalline hydrate of double cesium europium sulfate [CsEu(H2O)3(SO4)2]·H2O was synthesized by the crystallization from an aqueous solution containing equimolar amounts of 1Cs+:1Eu3+:2SO42− ions. Anhydrous salt CsEu(SO4)2 was formed as a result of the thermal dehydration of the crystallohydrate. The unusual effects observed during the thermal dehydration were attributed to the specific coordination of water molecules in the [CsEu(H2O)3(SO4)2]·H2O structure. The crystal structure of [CsEu(H2O)3(SO4)2]·H2O was determined by a single crystal X-ray diffraction analysis, and the crystal structure of CsEu(SO4)2 was obtained by the Rietveld method. [CsEu(H2O)3(SO4)2]·H2O crystallizes in the monoclinic system, space group P21/c (a = 6.5574(1) Å, b = 19.0733(3) Å, c = 8.8364(2) Å, β = 93.931(1)°, V = 1102.58(3) Å3). The anhydrous sulfate CsEu(SO4)2 formed as a result of the thermal destruction crystallizes in the monoclinic system, space group C2/c (a = 14.327(1) Å, b = 5.3838(4) Å, c = 9.5104(6) Å, β = 101.979(3) °, V = 717.58(9) Å3). The vibration properties of the compounds are fully consistent with the structural models and are mainly determined by the deformation of non-rigid structural elements, such as H2O and SO42−. As shown by the diffused reflection spectra measurements and DFT calculations, the structural transformation from [CsEu(H2O)3(SO4)2]·H2O to CsEu(SO4)2 induced a significant band gap reduction. A noticeable difference of the luminescence spectra between cesium europium sulfate and cesium europium sulfate hydrate is detected and explained by the variation of the extent of local symmetry violation at the crystallographic sites occupied by Eu3+ ions, namely, by the increase in inversion asymmetry in [CsEu(H2O)3(SO4)2]·H2O and the increase in mirror asymmetry in CsEu(SO4)2. The chemical shift of the 5D0 energy level in cesium europium sulfate hydrate, with respect to cesium europium sulfate, is associated with the presence of H2O molecules in the vicinity of Eu3+ ion.

Development of a Fast Simultaneous Analysis Method for Determination of Middle Rare-Earth Elements in Monazite Samples

Rare earth elements are a set of seventeen metallic elements, which is an essential part of many high-tech devices. Hence, analysis and/or separation of the rare earth elements from their mineral become crucial. A novel analysis method combining ultraviolet-visible spectroscopic and multivariate analysis was developed to determine middle rare earth elements quickly and simultaneously. The data collected from ultraviolet-visible spectroscopic were analyzed by multivariate analysis. The results showed that the developed method has good accuracy and precision with a detection limit of 1.375 (± 0.012), 0.332 (± 0.004), 42.117 (± 0.200), 1.767 (± 0.011), and 0.576 (± 0.002) ppm, respectively for samarium, europium, gadolinium, terbium, and dysprosium. The interference effect of ammonium iron(II) sulfate hexahydrate, manganese(III) sulfate hydrate, calcium carbonate, sodium carbonate, and lead(II) nitrate were examined. The reliability of the proposed method was evaluated using monazite samples. Conclusively, the developed method was successfully applied to determine the middle rare earth elements in monazite samples.

Ion-exchange properties of Zn4(OH)6(SO4) 2.5H2O

The aim of the present study is to check the possibilities for ion exchange of a new zinc-hydroxy-sulfate-hydrate phase, Zn4(OH)6SO4·2–2.25H2O. The new zinc hydroxy sulfate hydrate phase was obtained by mixing of 0.5 g of Zn5(OH)8(NO3)2.2H2O and 50 ml of 1M Na2SO4 for 48h at room temperature and pH of the solution between 5–7. Ion-exchange properties were investigated by mixing of 0.2 g Zn4(OH)6(SO4) 2.5H2O with 20 ml water solution of NaCl, CaCl2 or SrCl2 with different concentrations (0.5М, 1М, or 2M) for different time (24h, 48h and 72h) at room temperature. The pH of the solutions varied in the range 6–8. The new phase has exchange properties potentials, like other zinc hydroxy sulfate hydrates composed of octahedral-tetrahedral layers. The results obtained for the kinetics of ion-exchange reactions are additional useful data for the solving of the structure of the new zinc-hydroxy-sulfate-hydrate phase in the future.

Does Application of 'phosphogypsum Organic’ to a Sandy BRIS Soil Has an Impact on Soil-plants-water Systems?

BackgroundPredominant sandy, Beach Ridges Interspersed with Swales (BRIS) soil is a problematical soil for agriculture. It requires structure and capacity improvement due to its weak composition, low water retention capacity and high leaching of nutrients. However, there are hopes to improve it using different fertilizers in combination with organic matter. Phosphogypsum organic (PG organic) is an agricultural soil conditioner formulated from industrial by-products and organic filler material. This research was carried out to investigate the accumulated levels of heavy metals and radionuclides in water, soil and plants between BRIS soil under PG organic conditioner treatment and normal BRIS soil.ResultsThe result revealed that the PG organic’s particles are as similar to the reported pattern for calcium sulfate hydrate through powder X-ray diffraction (XRD). The heavy metals measured in the surface and borehole water, and soils were below the target values for raw drinking water and in the Dutch list, respectively. The values for biological accumulation coefficients, contamination factors, I-geo index and pollution load index (PLI) showed that there was no accumulation of metals in grain, no contamination and no pollution in the BRIS soil that received from the PG organic. Natural radioactivity concentrations, 226Ra (238U series), 228Ra (232Th series), and 40K in the collected samples were also measured. Naturally occurring radionuclide concentrations, such as 226Ra, 228Ra, and 40K, in soil and plant tissue were found to be lower than the average value reported by several earlier studies in Malaysia. There was no leaching of natural occurring radionuclides to the groundwater, nor was there discharge to the nearest river. The calculated radium equivalent (Raeq) in soil for this study was lower than the recommended value of 370 Bq/kg soil.ConclusionTherefore, the application of PG organic to the studied soil had no impact on the soil, plants and water and suitable as a soil conditioner in BRIS soil.

A durable VO2(M)/Zn battery with ultrahigh rate capability enabled by pseudocapacitive proton insertion

Reversible hydroxyzinc sulfate hydrate deposition/dissolution in electrochemical process could be observed on cathode surface. Good long term stability retention could also be achieved at high current density of 20 A g−1.

Penggunaan Limbah Logam Tembaga yang Didaur Ulang untuk Antibakteri dan Degradasi Metil Merah Secara Fotolisis

<p><em>Metil merah merupakan salah satu zat warna golongan azo yang sering digunakan dalam industri dan laboratorium. Penggunaan metil merah dapat menimbulkan efek terhadap kesehatan dan lingkungan. Oleh sebab itu dilakukan metode fotodegradasi dengan menggunakan semikonduktor dan radiasi sinar tampak. Semikonduktor yang digunakan yaitu berbahan dasar tembaga sulfat hidrat dan perak nitrat. Prekusor tembaga sulfat hidrat dibuat dari pengolahan limbah logam tembaga hasil pemotongan tembaga yang ada di bengkel Lembaga Ilmu Pengetahuan Indonesia (LIPI) Bandung. Bahan semikonduktor juga memiliki kemampuan dalam menghambat pertumbuhan bakteri. Hasil optimum yang didapatkan dalam proses fotodegradasi dan antibakteri merupakan gabungan antara kedua prekusor tembaga sulfat hidrat dan perak nitrat dengan bantuan penyinaran. Kemampuan dalam menghambat pertumbuhan bakteri didapatkan persentase kematian 100 % untuk masing-masing bakteri, yaitu Escherichia coli dan Staphylococcus aureus. Aktifitas fotokatalitiknya dengan konsentrasi semikonduktor 10 ppm untuk mendegradasi zat warna metil merah 5 ppm, selama 23 jam, dimana persentase degradasi yang didapatkan dengan penyinaran lebih tinggi dibandingkan dengan tanpa penyinaran. Pengaruh pH larutan terhadap degradasi metil merah yaitu optimum pada pH 12 (basa).</em></p><p><em><br /></em></p><p><em>Methyl red is one of the azo group dyes that is often used in industry and laboratories. The use of methyl red can have an effect on health and the environment. Therefore photodegradation method is done by using semiconductor and visible light radiation. The semiconductor used is based on copper sulfate hydrate and silver nitrate. The copper sulphate hydrate precursor is made from the processing of copper-cut copper metal waste in the workshop of the Indonesian Institute of Sciences (LIPI) in Bandung. Semiconductor materials also have the ability to inhibit bacterial growth. The optimum results obtained in the photodegradation and antibacterial process are a combination of both copper sulfate hydrate precursor and silver nitrate with the help of irradiation. The ability to inhibit bacterial growth obtained 100% mortality for each bacterium, namely Escherichia coli and Staphylococcus aureus. Photocatalytic activity with 10 ppm semiconductor concentration to degrade methyl red dye 5 ppm, for 23 hours, where the percentage of degradation obtained by irradiation is higher than without irradiation. The effect of pH of the solution on the degradation of methyl red is optimum at pH 12 (base).</em></p>