Search Results (65)

The development of efficient and biocompatible sorbent nanomaterials for cesium removal is critical for environmental and biomedical decontamination. Here, hybrid composites based on ultra-small Prussian blue or Zn Prussian blue-type nanoparticles confined within porous chitosan beads are proposed for Cs⁺ extraction. Nanoparticle confinement ensures homogeneous dispersion and improved accessibility of ion-exchange sites, while preserving the porous polymeric network, as confirmed by physicochemical characterization. Cs⁺ adsorption was investigated under neutral and acidic conditions (pH 7.2 and 1.2), at concentrations of 0–9 mmol/L and contact times of 0–50 h, showing efficient uptake and favorable kinetics, with confirmed stability in simulated gastric fluid. In vivo performance was assessed in a mouse model of cesium contamination (70 mg Cs⁺/kg). Treatment with nanocomposites (225 mg/kg) was compared to bulk Prussian blue (75 mg/kg), revealing enhanced detoxification efficiency. Histological analysis of liver, spleen, and kidney tissues showed no detectable structural damage, consistent with unchanged systemic biomarkers. Overall, the proposed chitosan-confined Prussian blue-type nanocomposites combine high Cs⁺ removal efficiency, kinetic accessibility, and in vivo safety, highlighting their potential for decorporation applications. Full article

All-inorganic cesium lead iodide (CsPbI₃) has been investigated for more than a decade as an absorber for perovskite photovoltaics thanks to its attractive bandgap, thermal robustness compared with hybrid perovskites, and compatibility with tandem concepts. Yet, despite remarkable efficiency progress, CsPbI₃ remains far from widespread commercialization. The core roadblock is the metastability of the photoactive black perovskite phases (α/γ/β) against transformation to the photoinactive yellow δ-phase under realistic conditions, amplified by defect chemistry, ion migration, and interfacial reactions. Additional barriers arise from scale-up constraints (film uniformity, throughput, solvent management), long-term operational stability (humidity, heat, UV, bias), and environmental/safety requirements, especially lead containment, sequestration, and end-of-life strategies. This review critically analyzes the intertwined physical, chemical, and engineering factors that still limit CsPbI₃ deployment, with emphasis on how solutions in one domain can fail without co-design in others. This review summarizes state-of-the-art stabilization strategies (size/strain engineering, additive/doping routes, surface/interface passivation, and encapsulation), highlight scalable manufacturing pathways including solvent-minimized and vacuum-assisted approaches, and discuss lead-mitigation technologies such as Pb-adsorbing functional layers. Finally, I argue that artificial intelligence (AI)—from machine-learning stability models to process monitoring, robotic optimization, and digital twins—has become essential to navigate the enormous parameter space of CsPbI₃ materials and manufacturing. It concludes with actionable recommendations and future directions toward bankable, scalable, and sustainable CsPbI₃ photovoltaics. Full article

The selective removal of radioactive cesium-137 and strontium-90 from high-salinity radioactive wastewater remains a critical challenge, as competing ions reduce adsorption efficiency and selectivity. In this study, high-performance granulated adsorbents were developed based on alkali-activated geopolymer matrices to enhance sorption performance. The adsorbents were synthesized by inorganic polymerization, and mechanically robust granules with controlled porosity and surface chemistry were obtained. Batch sorption experiments conducted in simulated seawater demonstrated greater than 99% removal efficiencies for cesium and strontium. Isotherm modeling confirmed high maximum sorption capacities (up to 0.41 meq/g for Cs⁺ and 5.07 meq/g for Sr²⁺). Continuous fixed-bed column tests demonstrated sustained removal efficiencies for the optimized adsorbents. Structural analyses, including scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, and X-ray diffraction, confirmed uniform elemental distribution and crystalline phases consistent with selective sorption mechanisms. Assessment of mechanical strength revealed sufficient compressive strengths to ensure operational durability under hydraulic stress. These findings demonstrate that the synthesized geopolymer-based granules are a potentially effective and versatile solution for the comprehensive treatment of radioactive wastewater. Full article

Metal halide perovskites have appeared as a promising semiconductor for high-efficiency and low-cost photovoltaic technologies. However, their performance and long-term stability are dramatically constrained by defects at the surface and grain boundaries of polycrystalline perovskite films formed during the processing. Herein, we propose a defect-targeted passivation strategy using 2-chlorocinnamic acid (2-Cl) to simultaneously enhance the efficiency and stability of perovskite solar cells (PSCs). The crystallization kinetics, film morphology, and optical and electronic properties of the used formamidinium–cesium lead halide (FA_0.85Cs_0.15Pb(I_0.95Br_0.05)₃, FACs) absorber were modulated and systematically investigated by various characterizations. Mechanistically, the carbonyl group in 2-Cl coordinates with undercoordinated Pb²⁺ ions, while the chlorine atom forms Pb–Cl bonds, effectively passivating the surface and interfacial defects. The optimized FACs perovskite film was incorporated into inverted (p-i-n) PSCs with a typical architecture of ITO/NiO_x/PTAA/Al₂O₃/FACs/PEAI/PCBM/BCP/Ag. The optimal device delivers a champion power conversion efficiency (PCE) of 22.58% with an open-circuit voltage of 1.14 V and a fill factor of 82.8%. Furthermore, the unencapsulated devices retain 90% of their initial efficiency after storage in ambient air for 30 days and 83% of their original PCE after stress under 1 sun illumination with maximum power point tracking at 50 °C in a N₂ environment, demonstrating the practical potential of dual-site molecular passivation for durable perovskite photovoltaics. Full article

The present investigation explores the potential of two synthesized zeolites, derived from coal fly ash (CFA; thermoelectric waste) and sugarcane bagasse ash (SCBA; agro-industrial waste), for the selective adsorption of cesium in wastewater. The synthesized zeolites (ZCFA and ZSCBA) were characterized and compared with a commercial zeolite to evaluate their physicochemical properties and effectiveness in removing cesium ions (Cs⁺) from simulated radioactive wastewater. The results obtained from X-ray diffraction, scanning electron microscopy, and elemental analysis confirmed the successful synthesis of high-purity zeolite from both solid wastes. The impurities present in the ashes impacted the Si/Al ratio and consequently influenced the exchange capacity. After adsorption experiments, neutron activation analysis (NAA) revealed that ZSCBA adsorbed 33.4% of Cs₂O by weight, outperforming both ZCFA (26.0%) and commercial zeolite (27.9%). The superior performance of ZSCBA is attributed to its distinct Si/Al ratio and lower levels of impurities, highlighting the impact of these factors on adsorption selectivity. The findings in this study demonstrate the feasibility of valorizing agro-industrial waste for synthesizing zeolites, offering a sustainable approach for managing these residues while producing valuable materials for environmental remediation. Full article

Recent studies have shown that the geothermal systems in Tibet are rich in rare metal elements such as lithium (Li), boron (B), rubidium (Rb), and cesium (Cs). However, the understanding of the origin of Cs-rich geyserite formed by hot springs remains unclear. In this study, a detailed petrological, elemental geochemical, and strontium–neodymium (Sr–Nd) isotopic investigation on Cs-rich geyserite in the Chabu region revealed that opal was the main mineral component of Chabu geyserite; here, some samples were rich in terrigenous clastic material, and well-developed diatom fossils were also present. Chabu geyserite had high contents of SiO₂ (78.95%–94.72%) and Al₂O₃ (3.02%–8.14%) and low contents of Fe₂O₃ (0.21%–1.94%), TiO₂ (0.01%–0.20%), MnO (0.01%–0.15%); additionally, the Fe/Ti ratio, the Al/(Al + Fe) ratio, and the Al/(Al + Fe + Mn) ratio showed large variations. These results indicated different degrees of participation by the terrigenous materials, hydrothermal deposition, and biogenic processes. Chabu geyserite was depleted in transition metal elements (e.g., Sc, V, and Cr) and high field strength elements (e.g., Nb, Zr, and Hf), relatively enriched in large-ion lithophile elements (e.g., Li, Rb, Sr, and Ba), and strongly enriched in Cs, (by up to 100 times the Cs content in the upper crust); in addition, it had low V/Y (1.30–2.00) and U/Th ratios. Chabu geyserite exhibited a right-dipping rare earth element (REE) distribution pattern and had significant negative Eu anomalies (0.26–0.72) and no or weak positive Ce anomalies (0.97–1.36). These results further indicated the influence of terrigenous clastic materials and nonhydrothermal sedimentation factors. The Sr–Nd isotopic composition of Chabu geyserite was significantly different from that of the mantle, with relatively high ⁸⁷Sr/⁸⁶Sr ratios (0.7070–0.7076) and low ¹⁴³Nd/¹⁴⁴Nd ratios (0.512223–0.512314). These ratios were similar to those of the crust. Combined with previous studies, the results from this study indicated that Chabu geyserite was a Cs-rich geyserite and was formed in an intracontinental post-collisional orogenic environment, mainly from crustal material, with the participation of biological and hydrothermal processes. Full article

The growing demand for alkali metals (AMs), such as lithium, cesium, and rubidium, related to their wide application across various industries (e.g., electronics, medicine, aerospace, etc.) and the limited resources of their naturally occurring ores, has led to an increased interest in methods of their recovery from secondary sources (e.g., brines, wastewater, waste leachates). One of the dynamically developing research directions in the field of separation of AMs ions from various aqueous solutions is the search for novel, efficient, and “green” materials that could be used in adsorption processes, also on a larger industrial scale. This review concerns the latest achievements (mainly from 2023 to 2024) in the development of innovative adsorption materials (e.g., ion sieves, aluminum-based adsorbents, mineral adsorbents, composites, resins) for the separation of Li⁺, Cs⁺, and Rb⁺ ions from solutions, with particular emphasis on their most important advantages and limitations, as well as their potential impact on the environment. Full article

Rubidium and cesium are important strategic resources, and West Taijinar Salt Lake is rich in rubidium and cesium reserves, while the concentration is low and the relationship with coexisting potassium and magnesium ions is complex. In order to understand the evaporative enrichment and salt precipitation patterns of rare elements such as lithium, rubidium, cesium, and boron of the brine after potassium precipitation in West Taijinar Salt Lake, the 288.2 K isothermal evaporation experiment was carried out. The experimental results show that during the evaporation process at 288.2 K, the following salts precipitate from the brine after potassium crystallization: halite (NaCl), bischofite (MgCl₂·6H₂O), carnallite (KCl·MgCl₂·6H₂O), hexahydrite (MgSO₄·6H₂O), epsomite (MgSO₄·7H₂O), boric acid (H₃BO₃), and lithium sulfate monohydrate (Li₂SO₄·H₂O). The concentrations of lithium and boron are significantly enriched, the content of Li⁺ was enriched from 1.7 g/L to 5.63 g/L, and the B₂O₃ content was enriched from 6.72 g/L to 50.78 g/L. The isomorphism phenomenon of Rb⁺, Cs⁺, and K⁺ makes Rb⁺ and Cs⁺ enter potassium ore to form solid solution-type carnallite ((K, Rb)MgCl₃·6H₂O, (K, Cs)MgCl₃·6H₂O)) and reduce the content of brine. This study provides data support for the development and comprehensive utilization of lithium, boron, rubidium, and cesium resources in West Taijinar Salt Lake. Full article

Sulfate-type salt lakes constitute over half of the total salt lakes in China and are rich in rare elements, such as rubidium and cesium. However, the complex interactions between ions make the separation and extraction process quite challenging. To address this, phase equilibrium studies were conducted on the sulfate system containing rubidium, cesium, and magnesium. Specifically, the phase equilibria of the aqueous quaternary system Rb⁺, Cs⁺, Mg²⁺//SO₄²⁻ - H₂O at 323.2 K were investigated using the isothermal dissolution method. The solubility, density, and refractive index of the system were experimentally measured. The results indicate that the system at 323.2 K belongs to a complex type with the formation of one solid solution (Rb, Cs)₂SO₄ and two double salts (Rb₂SO₄·MgSO₄·6H₂O, Cs₂SO₄·MgSO₄·6H₂O). The corresponding phase diagram consists of four quaternary invariant points, nine univariate curves, and six crystallization regions. Among these, the crystalline region for Cs₂SO₄·MgSO₄·6H₂O is the largest, while that for the single salt Cs₂SO₄ is the smallest. Moreover, the crystalline regions for the double salt and solid solutions are significantly larger than those for the single salt, highlighting the difficulty in separation of valuable single salts. A comparison of multi-temperature phase diagrams from 298.2 K to 323.2 K reveals that the crystalline form of MgSO₄ changes from MgSO₄·7H₂O (298.2 K) to MgSO₄·6H₂O (323.2 K). As the temperature increases, the phase regions for Rb₂SO₄, Cs₂SO₄, (Rb, Cs)₂SO₄, and Cs₂SO₄·MgSO₄·6H₂O expand, while the phase region of Rb₂SO₄·MgSO₄·6H₂O contracts, indicating that the single salts (Rb₂SO₄, Cs₂SO₄) are more readily precipitated at higher temperature, which provides theoretical guidance for the future production and separation of Rb, Cs, and Mg from sulfate-type salt lakes. Full article

Rubidium and cesium are critical strategic elements, and their development and utilization are of great significance. In this study, a magnesium ammonium phosphate (MAP) adsorbent was prepared and characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) surface area analysis, and Fourier transform infrared spectroscopy (FTIR). The adsorption performance of the adsorbent for Rb⁺ and Cs⁺ in solution was investigated. The results showed that the adsorbent exhibited high adsorption capacities of 2.83 mol/g for Rb⁺ and 4.37 mol/g for Cs⁺. In simulated brine, the adsorbent demonstrated excellent selectivity for Cs⁺. Kinetic and thermodynamic studies indicated that the adsorption process followed a pseudo-second order kinetic model and Langmuir isotherm model. The primary adsorption mechanism was an ion exchange. The development of this adsorbent holds significant promise for the extraction of rubidium and cesium from liquid resources. Full article

Cesium doped WO₃ (Cs-WO₃) photocatalyst with high and stable oxidation activity was successfully synthesized by a one-step hydrothermal method using Cs₂CO₃ as the doped metal ion source and tungstic acid (H₂WO₄) as the tungsten source. A series of analytical characterization tools and oxygen precipitation activity tests were used to compare the effects of different additions of Cs₂CO₃ on the crystal structure and microscopic morphologies. The UV–visible diffuse reflectance spectra (DRS) of Cs-doped material exhibited a significant red shift in the absorption edge with new shoulders appearing at 440–520 nm. The formation of an oxygen vacancy was confirmed in Cs-WO₃ by the EPR signal, which can effectively regulate the electronic structure of the catalyst surface and contribute to improving the activity of the oxygen evolution reaction (OER). The photocatalytic OER results showed that the Cs-WO₃-0.1 exhibited the optimal oxygen precipitation activity, reaching 58.28 µmol at 6 h, which was greater than six times higher than that of WO₃-0 (9.76 μmol). It can be attributed to the synergistic effect of the increase in the conduction band position of Cs-WO₃-0.1 (0.11 V) and oxygen vacancies compared to WO₃-0, which accelerate the electron conduction rate and slow down the rapid compounding of photogenerated electrons–holes, improving the water-catalytic oxygen precipitation activity of WO₃. Full article

Recently, the utilization of metal halide perovskites in sensing and their application in environmental studies have reached a new height. Among the different metal halide perovskites, cesium lead halide perovskites (CsPbX₃; X = Cl, Br, and I) and composites have attracted great interest in sensing applications owing to their exceptional optoelectronic properties. Most CsPbX₃ nanostructures and composites possess great structural stability, luminescence, and electrical properties for developing distinct optical and photonic devices. When exposed to light, heat, and water, CsPbX₃ and composites can display stable sensing utilities. Many CsPbX₃ and composites have been reported as probes in the detection of diverse analytes, such as metal ions, anions, important chemical species, humidity, temperature, radiation photodetection, and so forth. So far, the sensing studies of metal halide perovskites covering all metallic and organic–inorganic perovskites have already been reviewed in many studies. Nevertheless, a detailed review of the sensing utilities of CsPbX₃ and composites could be helpful for researchers who are looking for innovative designs using these nanomaterials. Herein, we deliver a thorough review of the sensing utilities of CsPbX₃ and composites, in the quantitation of metal ions, anions, chemicals, explosives, bioanalytes, pesticides, fungicides, cellular imaging, volatile organic compounds (VOCs), toxic gases, humidity, temperature, radiation, and photodetection. Furthermore, this review also covers the synthetic pathways, design requirements, advantages, limitations, and future directions for this material. Full article

The side chain alkylation of toluene with methanol was studied on a series of CsX catalysts prepared by varying the Cs species and ion exchange conditions. The effects of various parameters, such as the exchanging temperatures and times on the adsorption/activation properties of different CsX catalysts, were investigated by combining a variety of characterization means for understanding the role of Cs species in the side chain alkylation reaction. On the basis of the various characterization results and their related literature results, it can be proposed that the Cs ions located on the ion-exchanged sites of X zeolites could effectively adsorb and activate toluene molecularly through modifying the basicity of framework oxygen, whereas the cluster of cesium oxide (Cs₂O) could ensure the effective conversion of methanol into formaldehyde. Additionally, Cs ions can promote the production of monodentate formate, which enhances the selectivity of styrene. However, too much Cs₂O will lead to the excessive decomposition of methanol into CO₂, CO, and H₂, thus inhibiting the production of styrene. In summary, the presence of suitable amounts of Cs ions and Cs₂O clusters plays a significant role in the formation of the side chain products of styrene and ethylbenzene. Full article

For the first time, new sorbents based on polyacrylonitrile (PAN) fiber and transition metal ferrocyanides were obtained. The main difference between the obtained sorbents and the existing ones is the stage of preliminary preparation of the initial support by converting it into the forms PAN-Fe(OH)₃ or PAN-MnO₂, due to which additional ion exchange groups (carboxyl, carbonyl, etc.) are formed, which increases the amount of ferrocyanide fixed to the support. The best components and conditions for the synthesis of new sorbents were determined (concentration (0.1–0.2 mol/L), as well as pH (1 for sorbents based on PAN-Fe(OH)₃, and 1–5—PAN-MnO₂) of potassium ferrocyanide solution, concentration of transition metal salts (0.02 mol/L), temperature conditions). The influence of the studied solution composition (pH, concentration of Na⁺, K⁺, NH₄⁺ ions) on the cesium distribution coefficients during its recovery by the obtained sorbents was assessed. The possibility of cesium recovery from solutions with pH 1–9 containing macro quantities of cations was demonstrated. The sorbents derived were characterized by modern structural methods such as infrared spectroscopy, thermogravimetric analysis, and scanning electron microscopy with EDS analysis. A study of the trace amount sorption of ¹³⁷Cs was carried out in comparison with commercially available highly efficient sorbents (FNS-10 and Termoksid-35), and it was shown that the resulting sorbents are not inferior to industrial ferrocyanide sorbents and can be used for ¹³⁷Cs selective sorption from technological solutions and natural waters. Full article

Conditioning of radioactive waste generated from the operation of medical institutions, nuclear cycle facilities, and nuclear facilities is important for the safety of the environment. One of the most hazardous radionuclides is radioactive cesium. There is a need for more effective solutions to contain radionuclides, especially cesium (Cs+). Geopolymers are promising inorganic materials that can provide a large active surface area with adjustable porosity and binding capacity. The existence of nanosized zeolite-like structures in aluminosilicate gels was shown earlier. These structures are candidates for immobilizing radioactive cesium (Cs⁺). However, the mechanisms of their interactions with the aluminosilicate framework related to radionuclide immobilization have not been well studied. In this work, the influence of alkaline cations (Na⁺ or K⁺) and the aluminosilicate framework structure on the binding capacity and mechanism of interaction of geopolymers with Cs⁺ is explored in the example of a sodalite framework. The local structure of the water molecules and alkaline ions in the equilibrium state and its behavior when the Si/Al ratio was changed were studied by DFT. Full article