Search

The present work deals with developing a method for revalorizing steel residues to create sunlight-active photocatalysts based on iron oxides. Commercial-grade steel leftovers are oxidized under different combinations of pH and temperature (50–90 °C and 3 ≥ pH ≤ 5) in a low energy-intensive setup. The material with the highest production efficiency (yield > 12%) and magnetic susceptibility (χm = 387 × 10−6 m3/kg) was further explored and modified by diffusion of M2+ (Zn and Co) ions within the structure of the oxide using a hydrothermal method to create ZnFe2O4, CoFe2O4 and combined Co–Zn ferrite. (Co–Zn)Fe2O4 displayed a bandgap of 2.02 eV and can be activated under sunlight irradiation. Electron microscopy studies show that (Co–Zn)Fe2O4 consists of particles with diameters between 400 and 700 nm, homogeneous size, even distribution, and good dispersibility. Application of the developed materials in the sunlight catalysis of black liquors from cellulose extraction resulted in a reduction of the Chemical Oxygen Demand (− 15% on average) and an enhancement in biodegradability (> 0.57 BOD/COD) after 180 min of reaction. Since the presented process employs direct solar light, it opens the possibility to large-scale water treatment and chemical upgrading applications. [ABSTRACT FROM AUTHOR]

Quest for efficient and lead-free perovskite absorber layer is the need of the hour. The less explored titanium-based halide perovskites might be the non-toxic answer for the efficient yet toxic, organic, lead-based halide perovskite. It is of great interest to synthesize cesium titanium iodide perovskite and to investigate their novel properties. We have reported the synthesis of vacancy-ordered double perovskite cesium titanium iodide (Cs2TiI6) at room temperature. Structural, electrical and optical properties are investigated. Broad photoluminescence spectrum is observed. Absorbance and stability of this compound are discussed in detail. Using the absorption data, we have simulated solar cells with different transport layers to give an insight into its application. [ABSTRACT FROM AUTHOR]

Nanoparticles can enhance the intensity of susceptible vibrational modes through electromagnetic or chemical enhancement mechanisms responsible for the SERS effect (Surface-enhanced Raman spectroscopy). In the present work, copper nanoparticles (CuNP) with diameters between 3 and 10 nm were obtained by a simple method using rongalite and gelatin. The UV–Vis spectrum showed a well-defined absorption band centered at 570 nm, attributed to the surface plasmon resonance (SPR) of CuNP in a colloidal solution. The SERS effect was analyzed on the pyridine (Py) molecule, observing an enhancement in the radial breathing mode of Py. Complementarily, Cu4n clusters (with n = 1–5) were modeled under the DFT (Density Functional Theory) framework at the B3LYP (Becke, 3-parameter, Lee–Yang–Parr) approximation level in combination with the LANL2DZ base set (Los Alamos National Laboratory 2 Double-Zeta). After analyzing the molecular descriptors, the Cu4n-Py interaction study provided hints of SERS behavior. [ABSTRACT FROM AUTHOR]