The fungi
Aureobasidium pullulans
,
Mortierella humilis
,
Trichoderma harzianum and Phoma glomerata
were used to investigate the formation of selenium- and tellurium-containing nanoparticles during ...growth on selenium- and tellurium-containing media. Most organisms were able to grow on both selenium- and tellurium-containing media at concentrations of 1 mM resulting in extensive precipitation of elemental selenium and tellurium on fungal surfaces as observed by the red and black colour changes. Red or black deposits were confirmed as elemental selenium and tellurium, respectively. Selenium oxide and tellurium oxide were also found after growth of
Trichoderma harzianum
with 1 mM selenite and tellurite as well as the formation of elemental selenium and tellurium. The hyphal matrix provided nucleation sites for metalloid deposition with extracellular protein and extracellular polymeric substances localizing the resultant Se or Te nanoparticles. These findings are relevant to remedial treatments for selenium and tellurium and to novel approaches for selenium and tellurium biorecovery.
•The action of RF-07 suggests that it has anti-inflammatory activity.•The action of RF-07 suggests that it reduces the burden of Leishmania.•The action of RF-07 suggests that its toxic activity is ...low.
Tellurium compounds have been described as potential leishmanicides, bearing promising leishmanicidal and antimalarial effects. Therefore, the present study investigated the pharmacological potential of the organotellurane compound RF07 through preADMET parameters, such as absorption, distribution, metabolism and excretion. After studying the pharmacokinetic properties of RF07, studies were carried out on dogs naturally infected with visceral leishmaniasis after the administration of RF07, in order to assess pathophysiological parameters. Thus, dogs were divided into 4 groups with administration of daily intraperitoneal injections for 3 weeks (containing RF07 or placebo). During the trial, hematological parameters, renal and hepatic toxicity were evaluated. Serum urea, creatinine, alkaline phosphatase, transaminases (GOT and GPT), as well as hemogram results, were evaluated before the first administration and during the second and third weeks after the start of the treatment. In dogs with VL, RF07 improved liver damage, regulated GPT levels and significantly decreased leukocyte count, promoting its regularization. These phenomena occurred at the end of the third week of treatment. The administration of RF07 promoted a significant decrease in the average levels of GOT and GPT after the third week of treatment and did not significantly alter the hematological parameters. The application of RF07 in the treatment of visceral leishmaniasis suggests that it is an alternative to the disease, since the reversal of clinical signs in dogs with VL requires the use of 0.6 mg/kg.
The synthesis and reactivity of the heavier group 13 phosphaketene complexes (2,6-Mes
2
C
6
H
3
)
2
EPCO (
1
, E = Ga;
2
, E = In) were reported. The reaction of
1
and
2
with ...1,2,3,4-tetramethylimidazolin-2-ylidene, IMe
4
, gave rise to the formation of (2,6-Mes
2
C
6
H
3
)
2
EP(O)C(IMe
4
) (
3
, E = Ga;
4
E = In; Mes = mesityl). Subsequent addition of elemental tellurium proceeded
via
insertion into the E-P bond and provided (2,6-Mes
2
C
6
H
3
)
2
ETeP(O)C(IMe
4
) (
5
, E = Ga;
6
, E = In) comprising five-membered ETePCO-heterocycles. Compounds
1-6
were fully characterized by X-ray crystallography and heteronuclear NMR spectroscopy. The electronic structures of
1-6
were studied by DFT calculations and analyses of a complementary set of real-space bonding indicators (AIM, ELI-D, NCI) derived from the electron and pair densities, with focus on the bond characteristics of the PCO fragment.
Kinetically stabilized group 13 phosphaketene complexes (2,6-Mes
2
C
6
H
3
)
2
EPCO were used to prepare (2,6-Mes
2
C
6
H
3
)
2
ETeP(O)C(IMe
4
) comprising five-membered ETePCO-heterocycles (E = Ga, In; IMe
4
= 1,2,3,4-tetramethylimidazol-2-ylidene).
Zinc ion batteries (ZIBs), generally established on an excessive metallic Zn anode and aqueous electrolytes, suffer from severe dendrites and gassing issues at Zn side, resulting in poor cycling ...life. Substituting Zn metal anode with non‐Zn ones is a promising strategy for solving these problems, whereas this is still restricted by the limited anode alternatives. Herein, by replacing metal Zn with chalcogen element tellurium (Te), a conversion‐type Te‐based ZIB is reported that can work in both mild and alkaline electrolytes. As expected, the as‐assembled mild Te/MnO2 and alkaline Te/Ni(OH)2 cells deliver remarkable capacities up to 106 and 161 mAh g−1anode+cathode, respectively, with a high utilization of anode (50.1% for the Te/MnO2 and 38.9% for the Te/Ni(OH)2), which surpass all ZIBs. Ultralong cycling life (over 75% capacity retention after 5000 cycles) is achieved in the two systems, benefiting from the stable conversion mechanisms (mild: Te to ZnTe2 to ZnTe; alkaline: ZnTe to Te to TeO2) with thoroughly eliminated dendrites and gassing. Moreover, high gravimetric energy density of ZIBs is also achieved, which are 176.3 Wh kg−1anode+cathdoe (Te/Ni(OH)2) and 81 Wh Kg−1anode+cathode (Te/MnO2), respectively. This work sheds light on the development of advanced conversion‐type anode for high‐performance batteries with superior stability.
Tellurium (Te), a new conversion‐type anode for zinc‐ion batteries is developed, which is compatible in both mild and alkaline electrolytes. The as‐assembled mild Te/MnO2 and alkaline Te/Ni(OH)2 cells thoroughly eliminate the dendrites and gassing issues in common zinc batteries, which deliver remarkable capacities, long cycling life, and high energy density with a high utilization of anode.
The emerging potassium‐tellurium (K‐Te) battery system is expected to realize fast reaction kinetics and excellent rate performance due to the exceptional electrical conductivity of Te. However, ...there has been a lack of fundamental knowledge about this new K‐Te system, including the reaction mechanism and cathode structure design. Herein, a two‐step reaction pathway from Te to K2Te3 and ultimately to K5Te3 is investigated in carbonate electrolyte‐based K‐Te batteries by X‐ray diffraction, high‐resolution transmission electron microscopy, and selected area electron diffraction characterizations. Additionally, the atomic layer deposition technique is adopted to deposit an ultrathin aluminum oxide (Al2O3) film on the electrode surface, which induces the generation of a stable solid electrolyte interphase layer and reduces the loss of active materials effectively. Consequently, the rationally fabricated Te/porous carbon cathode with functional Al2O3 coating delivers remarkable long‐term cycling stability over 500 cycles at 1 C with an ultralow capacity decay of only 0.01% per cycle. This interface engineering strategy is validated to stabilize the electrode surface, enhance the structural integrity and ensure reliable electron transfer and K‐ion conduction over repeated potassiation/depotassiation cycles. These findings are expected to promote the development of high‐energy‐density K‐S/Se/Te batteries.
A durable and high‐rate potassium‐tellurium (K‐Te) battery is designed by depositing an ultrathin aluminum oxide layer via the atomic layer deposition technique on the Te cathode surface. The rationally fabricated Te/porous carbon cathode with coating layer delivers remarkable long‐term cycling stability over 500 cycles at 1 C with an ultralow capacity decay of only 0.01% per cycle.
Solid‐state thermoelectric (TE) technology is a promising approach to harvest low‐grade waste heat (<573 K) and converts it to useful electricity in industrial and civilian settings. After decades of ...efforts in improving the figure‐of‐merit (zT) of TE materials, the development of advanced modules has started springing up in recent years. Although high‐performance modules have been largely reported based on the successful material improvement, it remains less investigated how and whether the module‐level designs can further increase the conversion efficiency. Herein, following the recent demonstration of a tellurium (Te)‐free TE generator, an increase is demonstrated in the efficiency by reducing both the electrical and thermal energy losses through simply optimizing geometric factors of filling factor and leg‐pair numbers. These module‐level optimizations enable a record conversion efficiency of 8.2% under a ∆T ≈ 260 K, thus fulfilling 90% of the theoretical efficiency of the materials and solidly exceeding the Bi2Te3 modules. Furthermore, module robustness against > 10 160 thermal cycles while preserving a relative efficiency of 95% is demonstrated. These findings highlight the importance of the optimization strategy at the module level and demonstrate the feasibility of using Te‐free thermoelectric compounds to harvest the omnipresent low‐grade heat.
By optimizing the geometrical configurations of thermoelectric modules based on MgAgSb/Mg3(Sb,Bi)2 including the filling factor and the number of leg pairs, both the electrical and thermal energy losses are reduced. A record conversion efficiency of 8.2% is realized under a temperature difference of 260 K, thus fulfilling 90% of the theoretical efficiency of the materials and transcending the Bi2Te3 modules.
In this work, Te/poly(3,4-ethylenedioxythiophene) (PEDOT):poly(styrenesulfonate) (PSS)/Cu
Te
ternary thermoelectric (TE) nanocomposite films were successfully fabricated by physical mixing and then ...drop casting. An optimum power factor of 65.3 μW/mK
was acquired from a composite film containing 95 wt % PEDOT:PSS-coated Te (PC/Te) nanorods at 300 K, which was about 5 times as large as that of the PC/Cu
Te
nanorod film and about 3 times as large as that of the PC/Te nanorod film. The power factor reached 112.3 μW/mK
when the temperature was 380 K. Scanning transmission electron microscopy (STEM) and high-resolution STEM were used to observe the detailed internal microstructure of the composite film, revealing that the Te nanorods were single crystalline and the Cu
Te
rods polycrystalline. The composite film was in fact a three-dimensional network interconnected with the PC/Te and PC/Cu
Te
nanorods. The enhancement of the TE properties was ascribed to the synergetic effect of the two kinds of nanorods and the double-carrier filtering effect at the two heterointerfaces of Te/PEDOT:PSS and Cu
Te
/PEDOT:PSS. An eight single-leg flexible TE device consisting of the optimized composite film was fabricated, which produced a voltage of 31.2 mV and a maximum output power of 94.7 nW at a temperature gradient of 39 K.
•Improved access to 1,3-benzotellurazoles.•Regiospecific ortho tellurination of ureas via Te-carbonyl coordination.•Preparation of previously inaccessible 1,3-tellurazole derivatives.•Organotellurium ...compounds with high stability to heat, light and moisture.•X-ray crystallographic data for new organotellurium compounds.
A method has been developed to prepare previously inaccessible substituted 1,3-benzotellurazoles following an efficient two-step process, consisting of the tellurination of electron rich phenyl ureas with tellurium tetrachloride and subsequent ring closure of the resulting aryl tellurium trichlorides. Tellurination occurs regiospecifically ortho to the urea moiety due to intramolecular Te–O coordination, producing highly crystalline solids that are readily isolated in yields up to 83 %. Subsequent ring closure, accomplished by heating with phosphorus trichloride and subsequent reduction with hydrazine hydrate, provides access to 1,3-benzotellurazole derivatives. Selected products were characterized by X-ray crystallography.
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Elemental tellurium (Te) nanoparticles are increasingly important in a variety of applications such as thermoelectricity, photoconductivity, and piezoelectricity. However, they have been explored ...with limited success in their biomedical use, and thus a tremendous challenge still exists in the exploration of Te nanoparticles that can treat tumors as an effective anticancer agent. Here, we introduce bifunctional Te nanodots with well-defined nanostructure as an effective anticancer agent for photo-induced synergistic cancer therapy with tumor ablation, which is accomplished using hollow albumin nanocages as a nanoreactor. Under near-infrared light irradiation, Te nanodots can produce effective photothermal conversion, as well as highly reactive oxygen species such as •O2 – and dismutated •OH via a type-I mechanism through direct electron transfer, thereby triggering the potent in vivo hyperthermia and simultaneous intracellular reactive oxygen species at tumors. Moreover, Te nanodots possess perfect resistance to photobleaching, effective cytoplasmic translocation, preferable tumor accumulation, as well as in vivo renal elimination, promoting severe photo-induced cell damage and subsequent synergy between photothermal and photodynamic treatments for tumor ablation. These findings provide the insight of elemental Te nanodots for biomedical research.
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