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Chemistry of Materials : a Publication... Nov 2023Lead-free perovskite nanocrystals are of interest due to their nontoxicity and potential application in the display industry. However, engineering their optical...
Lead-free perovskite nanocrystals are of interest due to their nontoxicity and potential application in the display industry. However, engineering their optical properties is nontrivial and demands an understanding of emission from both self-trapped and free excitons. Here, we focus on tuning silver-based double perovskite nanocrystals' optical properties via two iso-valent dopants, Bi and Sb. The photoluminescence quantum yield of the intrinsic CsAgNaInCl perovskite increased dramatically upon doping. However, the two dopants affect the optical properties very differently. We hypothesize that the differences arise from their differences in electronic level contributions and ionic sizes. This hypothesis is validated through absorption and temperature dependence photoluminescence measurements, namely, by employing the Huang-Rhys factor, which indicates the coupling of the exciton to the lattice environment. The larger ionic size of Bi also plays a role in inducing significant microstraining verified via synchrotron measurements. These differences make Bi more sensitive to doping concentration over antimony which displays brighter emission (QY ∼40%). Such understanding is important for engineering optical properties in double perovskites, especially in light of recent achievements in boosting the photoluminescence quantum yield.
PubMed: 37982006
DOI: 10.1021/acs.chemmater.3c01771 -
Journal of Environmental Management Oct 2023The spread of antimony from mine wastes to the environment represents a matter of great concern due to its adverse effects on impacted ecosystems. There is an urgent...
The spread of antimony from mine wastes to the environment represents a matter of great concern due to its adverse effects on impacted ecosystems. There is an urgent need for developing and adopting sustainable and inexpensive measures to deal with this type of wastes. In this study the Sb leaching behavior of mine waste rocks and mine tailings derived from the exploitation of Sb ore deposits was characterized using standard batch leaching tests (TCLP and EN-12457-4) and column leaching essays. Accordingly, these mine wastes were characterized as toxic (>0.6 mg Sb L) and not acceptable at hazardous waste landfills (>5 mg Sb kg), showing also an ongoing Sb release under prolonged leaching conditions. Two industrial by-products were evaluated as amendments to stabilize them, namely deferrisation sludge (DFS) and a by-product derived from the treatment of aluminum salt slags (BP-Al). Mine wastes were amended with different doses (0-25%) of DFS or BP-Al and the performance of these treatments was evaluated employing also batch and column leaching procedures. The effectiveness of DFS to immobilize Sb was much higher than that exhibited by BP-Al. Thus, treatments with 25% BP-Al showed Sb immobilization levels of approximately 33-53%, whereas treatments with 5 and 25% DFS already attained Sb immobilization levels up to approximately 80-90 and 90-99%, respectively. Mine tailings amended with 5% DFS and mine waste rocks amended with 25% DFS decreased their leachable Sb contents below the limit for non-hazardous waste landfill acceptance (<0.7 mg Sb kg). Likewise, these DFS treatments were able to revert their toxic characterization. Moreover, the 25% DFS treatment showed to be a long-lasting stabilizing system, efficient at least during a leaching period equivalent to 10-year rainfall with a great Sb leaching reduction (close to 98%). After this long-term leaching process, DFS-treated mine wastes kept their non-hazardous and non-toxic characterization. The amorphous Fe (oxyhydr)oxides composing DFS were responsible for the important Sb removal capacity showed by this by-product. Thus, when DFS was applied to mine wastes mobile Sb was importantly fixed as non-desorbable Sb, showing also a considerable Sb removal capacity in presence of strong competing anions such as phosphate. The application of DFS as amendment presents a great potential to be used as a sustainable long-term stabilizing system of Sb mine wastes.
Topics: Antimony; Ecosystem; Hazardous Waste
PubMed: 37247551
DOI: 10.1016/j.jenvman.2023.118218 -
ACS Applied Materials & Interfaces Sep 2023The rapidly expanding demand for photovoltaics (PVs) requires stable, quick, and easy to manufacture solar cells based on socioeconomically and ecologically viable...
The rapidly expanding demand for photovoltaics (PVs) requires stable, quick, and easy to manufacture solar cells based on socioeconomically and ecologically viable earth-abundant resources. SbS has been a potential candidate for solar PVs and the efficiency of planar SbS thin-film solar cells has witnessed a reasonable rise from 5.77% in 2014 to 8% in 2022. Herein, the aim is to bring new insight into SbS solar cell research by investigating how the bulk and surface properties of the SbS absorber and the current-voltage and deep-level defect characteristics of solar cells based on these films are affected by the ultrasonic spray pyrolysis deposition temperature and the molar ratio of thiourea to SbEX in solution. The properties of the SbS absorber are characterized by bulk- and surface-sensitive methods. Solar cells are characterized by temperature-dependent current-voltage, external quantum efficiency, and deep-level transient spectroscopy measurements. In this paper, the first thin-film solar cells based on a planar SbS absorber grown from antimony ethyl xanthate (SbEX) by ultrasonic spray pyrolysis in air are demonstrated. Devices based on the SbS absorber grown at 200 °C, especially from a solution of thiourea and SbEX in a molar ratio of 4.5, perform the best by virtue of suppressed surface oxidation of SbS, favorable band alignment, Sb-vacancy concentration, a continuous film morphology, and a suitable film thickness of 75 nm, achieving up to 4.1% power conversion efficiency, which is the best efficiency to date for planar SbS solar cells grown from xanthate-based precursors. Our findings highlight the importance of developing synthesis conditions to achieve the best solar cell device performance for an SbS absorber layer pertaining to the chosen deposition method, experimental setup, and precursors.
PubMed: 37640298
DOI: 10.1021/acsami.3c08547 -
Journal of Hazardous Materials Jun 2024Arsenic (As) and antimony (Sb) often co-occur in floodplain depositional environments that are contaminated by legacy mining activities. However, the distribution of As...
Arsenic (As) and antimony (Sb) often co-occur in floodplain depositional environments that are contaminated by legacy mining activities. However, the distribution of As and Sb throughout floodplains is not uniform, adding complexity and expense to management or remediation processes. Identifying floodplain morphology predictor variables that help quantify and explain As and Sb spatial distribution on floodplains is useful for management and remediation. We developed As and Sb risk maps estimating concentration and availability at a coastal floodplain wetland impacted by upper-catchment mining. Significant predictors of As and Sb concentrations included i) distance from distributary channel-wetland intersection and ii) elevation. Distance from channel explained 53 % (P < 0.01) and 28 % (P < 0.01), while elevation explained 42 % (P < 0.01) and 47 % (P < 0.01) of the variability in near-total Sb and As respectively. As had a higher extractability than Sb across all tested soil extractions, suggesting that As is more environmentally available. As and Sb dry mass estimates to a depth of 0.1 m scaled to the lower coastal Macleay floodplain ranged from 113-192 tonnes and 14-24 tonnes respectively. Landscape-scale modelling of metalloid distribution, informed by morphology variables, presented here may be a useful framework for the development of risk maps in other regions impacted by contaminated upper-catchment sediments.
PubMed: 38925052
DOI: 10.1016/j.jhazmat.2024.135013 -
PLoS Neglected Tropical Diseases Feb 2024Visceral leishmaniasis (VL) resolution depends on a wide range of factors, including the instauration of an effective treatment coupled to a functional host immune...
BACKGROUND
Visceral leishmaniasis (VL) resolution depends on a wide range of factors, including the instauration of an effective treatment coupled to a functional host immune system. Patients with a depressed immune system, like the ones receiving methotrexate (MTX), are at higher risk of developing VL and refusing antileishmanial drugs. Moreover, the alarmingly growing levels of antimicrobial resistance, especially in endemic areas, contribute to the increasing the burden of this complex zoonotic disease.
PRINCIPAL FINDINGS
To understand the potential links between immunosuppressants and antileishmanial drugs, we have studied the interaction of antimony (Sb) and MTX in a Leishmania infantum reference strain (LiWT) and in two L. infantum clinical strains (LiFS-A and LiFS-B) naturally circulating in non-treated VL dogs in Spain. The LiFS-A strain was isolated before Sb treatment in a case that responded positively to the treatment, while the LiFS-B strain was recovered from a dog before Sb treatment, with the dog later relapsing after the treatment. Our results show that, exposure to Sb or MTX leads to an increase in the production of reactive oxygen species (ROS) in LiWT which correlates with a sensitive phenotype against both drugs in promastigotes and intracellular amastigotes. LiFS-A was sensitive against Sb but resistant against MTX, displaying high levels of protection against ROS when exposed to MTX. LiFS-B was resistant to both drugs. Evaluation of the melting proteomes of the two LiFS, in the presence and absence of Sb and MTX, showed a differential enrichment of direct and indirect targets for both drugs, including common and unique pathways.
CONCLUSION
Our results show the potential selection of Sb-MTX cross-resistant parasites in the field, pointing to the possibility to undermine antileishmanial treatment of those patients being treated with immunosuppressant drugs in Leishmania endemic areas.
Topics: Humans; Animals; Dogs; Leishmania infantum; Methotrexate; Antimony; Reactive Oxygen Species; Antiprotozoal Agents; Leishmaniasis, Visceral; Drug Resistance
PubMed: 38422164
DOI: 10.1371/journal.pntd.0012015 -
Environmental Health : a Global Access... Oct 2023Fluoride is ubiquitous in the United States (US); however, data on biomarkers and patterns of fluoride exposure among US pregnant women are scarce. We examined specific...
BACKGROUND
Fluoride is ubiquitous in the United States (US); however, data on biomarkers and patterns of fluoride exposure among US pregnant women are scarce. We examined specific gravity adjusted maternal urinary fluoride (MUFsg) in relation to sociodemographic variables and metal co-exposures among pregnant women in Los Angeles, California.
METHODS
Participants were from the Maternal and Developmental Risks from Environmental and Social Stressors (MADRES) cohort. There were 293 and 490 women with MUFsg measured during first and third trimesters, respectively. An intra-class correlation coefficient examined consistency of MUFsg between trimesters. Kruskal-Wallis and Mann-Whitney U tests examined associations of MUFsg with sociodemographic variables. Covariate adjusted linear regression examined associations of MUFsg with blood metals and specific gravity adjusted urine metals among a subsample of participants within and between trimesters. A False Discovery Rate (FDR) correction accounted for multiple comparisons.
RESULTS
Median (IQR) MUFsg was 0.65 (0.5) mg/L and 0.8 (0.59) mg/L, during trimesters one and three respectively. During both trimesters, MUFsg was higher among older participants, those with higher income, and White, non-Hispanic participants than Hispanic participants. MUFsg was also higher for White, non-Hispanic participants than for Black, non-Hispanic participants in trimester three, and for those with graduate training in trimester one. MUFsg was negatively associated with blood mercury in trimester one and positively associated with blood lead in trimester three. MUFsg was positively associated with various urinary metals, including antimony, barium, cadmium, cobalt, copper, lead, nickel, tin, and zinc in trimesters one and/or three.
CONCLUSIONS
MUFsg levels observed were comparable to those found in pregnant women in Mexico and Canada that have been associated with poorer neurodevelopmental outcomes. Lower urinary fluoride levels among Hispanic and non-Hispanic Black participants in MADRES compared to non-Hispanic White participants may reflect lower tap water consumption or lower fluoride exposure from other sources. Additional research is needed to examine whether MUFsg levels observed among pregnant women in the US are associated with neurodevelopmental outcomes.
Topics: Female; Pregnancy; Humans; Pregnant Women; Fluorides; Los Angeles; Metals; Cadmium
PubMed: 37880740
DOI: 10.1186/s12940-023-01026-2 -
ACS Omega Aug 2023Contamination of water sources by toxic antimony Sb(III) ions poses a threat to clean water supplies. In this regard, we have prepared a mesoporous silica nanoparticle...
Contamination of water sources by toxic antimony Sb(III) ions poses a threat to clean water supplies. In this regard, we have prepared a mesoporous silica nanoparticle (MSN)-derived adsorbent by reverse microemulsion polymerization, using cetyltrimethylammonium chloride (CTAC) and triethanolamine (TEA) as co-templates. The physical and chemical properties were characterized using advanced tools. The MSN exhibits a higher surface area of up to 713.72 m·g, a pore volume of 1.02 cm·g, and a well-ordered mesoporous nanostructure with an average pore size of 4.02 nm. The MSN has a high adsorption capacity for toxic Sb(III) of 27.96 mg·g at pH 6.0 and 298 K. The adsorption data followed the Langmuir isotherm, while the kinetics of adsorption followed the pseudo-second-order model. Interestingly, the effect of coexisting iron showed a promoting effect on Sb(III) uptake, while the presence of manganese slightly inhibited the adsorption process. The recyclability of the MSN adsorbent was achieved using a 0.5 M HCl eluent and reused consecutively for three cycles with a more than 50% removal efficiency. Moreover, the characterization data and batch adsorption study indicated physical adsorption of Sb(III) by mesopores and chemical adsorption due to silicon hydroxyl groups.
PubMed: 37546683
DOI: 10.1021/acsomega.3c01735 -
RSC Advances Nov 2023Lately, double perovskite materials have become well-known in the commercialization area owing to their potential use in optoelectronic applications. Here, double...
Lately, double perovskite materials have become well-known in the commercialization area owing to their potential use in optoelectronic applications. Here, double perovskite CsAgSbCl single crystals (SCs) with cubic crystal structure and 3̄ space group were successfully synthesized the slow cooling technique. This paper investigates the dielectric relaxation and charge transfer mechanism within CsAgSbCl using electrochemical impedance spectroscopy (EIS) in the 273-393 K temperature range under light. The dielectric response in CsAgSbCl has been explained by the space charge polarization and the ionic motion. The '() study at different temperatures shows a remarkable frequency transition at which d'/d changes from a positive to a negative coefficient. Based on Stevels approach, the density of traps diminishes with the temperature increase, which improved conduction. However, this approach proves the polaronic conduction in CsAgSbCl. 0.42 and 0.21 eV are the binding () and polaron hopping () energy values, respectively. Contrary to free-charge carrier motion, polaron hopping was proposed as the principal conduction process since the ambient-temperature thermal energy was lower than . Moreover, the analysis of ''() and -''() as a function of temperature shows the thermally-activated relaxation from the non-Debye to Debye type model in CsAgSbCl. This scientific research offers an essential understanding of the dielectric relaxation behavior, which is required for improving dielectric switches. Also, this paper provides a deep insight into the conduction mechanism within double perovskite materials.
PubMed: 38035244
DOI: 10.1039/d3ra05857c -
Molecules (Basel, Switzerland) Jan 2024Two types of isostructural iron-cobalt/nickel-antimony-oxo tartrate cluster-based compounds, namely (HO)(MeNH)[(HO)][FeSb(-O)(-O)(tta)]·6HO ( = Co (); Ni ()),...
Two types of isostructural iron-cobalt/nickel-antimony-oxo tartrate cluster-based compounds, namely (HO)(MeNH)[(HO)][FeSb(-O)(-O)(tta)]·6HO ( = Co (); Ni ()), H[CoFeFe(HO)SbFe(-O)(-O)Sb(-O)(tta)]·2HO () and H[NiFeFe(HO)SbFe(-O)(-O)Sb(-O)(tta)]·2HO () (Htta = tartaric acid) were synthesized via simple solvothermal reactions. All the clusters in the structures adopt sandwich configurations, that is, bilayer sandwich configuration in and and monolayer sandwich configuration in and . Interestingly, the monolayer sandwiched compounds and represent rare examples of cluster-based compounds containing mixed-valence Sb(III, V), whose center of the intermediate layer is the co-occupied [FeSb]. This is different from that of previously reported sandwich-type antimony-oxo clusters in which the center position is either occupied by a transition metal ion or a Sb(V) alone. Thus, the discovery of title compounds and makes the evolution of center metal ion more complete, that is, from , Sb to Sb. All the title compounds were fully characterized, and the photocatalysis, proton conduction and magnetism of compounds and were studied.
PubMed: 38338337
DOI: 10.3390/molecules29030591 -
Molecules (Basel, Switzerland) Oct 2023Forming solid solutions is one of the most effective strategies to suppress the thermal conductivity of thermoelectric materials. However, the accompanying increase in...
Forming solid solutions is one of the most effective strategies to suppress the thermal conductivity of thermoelectric materials. However, the accompanying increase in impurity ion scattering usually results in an undesirable loss in hall mobility, negatively impacting the electrical transport properties. In this work, a tellurium-selenium (Te-Se) solid solution with trace antimony (Sb) doping was synthesized via the high pressure and high temperature method. It was found that slight Se doping into the Te sites not only had no impact on the hall mobility and carrier concentration, but also enhanced the density-of-state effective mass of SbTe, leading to an enhanced power factor near room temperature. Additionally, the presence of Se doping caused a significant reduction in the phonon thermal conductivity of Te due to fluctuations in the mass and strain field. The lowest phonon thermal conductivity was as low as ~0.42 WmK at 600 K for SbSeTe, which approached the theoretical minimum value of Te (~0.28 WmK). The effects of Se doping suppressed thermal conductivity, while Sb doping enhanced the power factor, resulting in a larger of ~0.94 at 600 K. Moreover, these findings demonstrate that Sb and Se doping can effectively modulate the electrical and thermal transport properties of Te in a synergistic manner, leading to a significant increase in the average across a wide temperature range.
PubMed: 37959707
DOI: 10.3390/molecules28217287