In this study, Sb₂Te₃ films were electrodeposited potentiostatically at room temperature from acidic nitric baths in the presence of a surfactant, cetyltrimethylammonium bromide (CTAB). This resulted in improvements in the surface morphologies of the films. The thus-deposited films also exhibited better adherence to their substrates. In addition, the carrier transport properties of the Sb₂Te₃ films, including their electrical conductivities and Seebeck coefficient values, could be improved by annealing them at 200 °C. This was due to the formation of Te nanodots in the Sb₂Te₃ matrix. The resulting Sb₂Te₃ films with Te nanodots 10–20 nm in size and a dispersion density of 11.4 vol% exhibited a high power factor of 716.0 μW m⁻¹ K⁻², which was about two times higher than that of Sb₂Te₃ films that did not contain Te nanodots. The results of the study suggested that the improvements in the thermoelectric characteristics of the films were due to carrier energy filtering at the Te–Sb₂Te₃ interface.

Heavy-metal-free carbon materials were prepared from spent coffee grounds (SCG) using the coupled KOH–urea and NaOH–urea as activating agents, and these were compared with SCG activation by the alkali salts alone. SCG was impregnated with the activating agents before being pyrolyzed at 800 °C under a N₂ atmosphere. Characterization of the as-pyrolyzed carbon materials was performed by field-emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and measurement of N₂ adsorption–desorption isotherms. The carbon materials were utilized for the adsorption of methylene blue (MB) in aqueous solutions. Combining KOH and urea as activating agents resulted in the generation of pertinent SCG-derived carbon material properties, including a large surface area (1665.45 m² g⁻¹) and excellent MB adsorption capacity. Adsorption efficiencies were studied using adsorption kinetics (pseudo-first-order and pseudo-second-order) and adsorption isotherm (Langmuir, Freundlich, and Temkin) models. The influences of pH and temperature were investigated. The results of this work raise new possibilities for synthesizing carbon materials with high MB adsorption capacities from biowastes, via less-toxic, energy-saving conventional pyrolysis methods for water-treatment applications.

The crystal facet of MAPbI₃ perovskite is purposefully controlled to achieve highly efficient and stable solar cells via nucleation modulation.

The embedding of nanoprecipitates into a semiconducting matrix can lead to improved thermoelectric performances by enhancing the power factor or reducing the thermal conductivity of the system in which they are incorporated. Thus, we herein demonstrate the successive annealing of an electrodeposited amorphous Ag–Sb–Te film for the simple and effective fabrication of a nanocomposite consisting of highly dense (∼6 vol%) β-Ag₂Te nanoprecipitates in an Ag-doped Sb₂Te₃ matrix. During the annealing process, nanoscale (∼40 nm) β-Ag₂Te precipitates were generated spontaneously due to differences in the binding energies of the Ag–Te and Sb–Te bonds. As a result, the electron-transport properties of the p-type Sb₂Te₃ were significantly enhanced in the presence of the β-Ag₂Te nanoprecipitates owing to an energy-dependent carrier-filtering effect at the Ag-doped Sb₂Te₃/β-Ag₂Te interface. Furthermore, a high power factor of 1870 μW m⁻¹ K⁻² was obtained at 300 K due to the increased density of states effective mass (m* ∼1.8m₀) without any significant deterioration in the electrical conductivity being observed.

The substitutional doping approach has been shown to be an effective strategy to improve ZT of Bi₂Te₃-based thermoelectric raw materials. We herein report the Fe-doping effects on electronic and thermal transport properties of polycrystalline bulks of p-type Bi_0.48Sb_1.52Te₃. After a small amount of Fe-doping on Bi/Sb-sites, the power factor could be enhanced due to the optimization of carrier concentration. Additionally, lattice thermal conductivity was reduced by the intensified point-defect phonon scattering originating from the mass difference between the host atoms (Bi/Sb) and dopants (Fe). An enhanced ZT of 1.09 at 300 K was obtained in 1.0 at% Fe-doped Bi_0.48Sb_1.52Te₃ by these synergetic effects.