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The bismuth (Bi)-substituted CuSb1-xBixSe2 chalcostibites were synthesized using the horizontal Bridgman-Stockbarger technique combined with ball milling, at temperatures ranging from 303 to 650 K. The impact of Bi substitution was observed in the thermoelectric transport properties by substituting Bi (x = 0, 0.2, 0.4, 0.6) resulted in a decreased Seebeck coefficient and higher electrical resistivity compared to the pure CuSbSe2 sample. Notably, the higher substitution level (x = 0.6) showed the enhanced properties compared to the lower levels. The pristine sample exhibited a power factor of 550 μWK−2 m−1, while the substituted samples showed the values of 20, 37 and 50 μWK−2 m−1, respectively. However, in accordance with the power factor, the pristine compound demonstrated a higher figure of merit (ZT = 0.47) compared to the existing literature values (ZT = 0.21), indicating the superior thermoelectric performance using this synthesis method. [ABSTRACT FROM AUTHOR]

Dye-sensitized solar cells (DSSCs) have gained recognition as a promising indoor photovoltaic technology, drawing considerable attention for their ability to convert light into electricity. In this study, we present a straightforward one-step hydrothermal synthesis method for producing cobalt sulfide nanoparticles decorated with reduced graphene oxide (CoS2/RGO) nanocomposites, serving as an efficient counter electrode (CE) material for DSSCs. The CoS2/RGO nanocomposites exhibited a chain-like structure formed by RGO nanosheet-decorated spherical particles interconnected with CoS2. Demonstrating excellent electrocatalytic activity with a low Epp (peak-to-peak separation) value, the CoS2/RGO nanocomposites outperformed pristine CoS2 nanoparticles. Moreover, the power conversion efficiency of the CoS2/RGO hybrid structure-based CE surpassed that of the pristine CoS2 nanoparticles. These findings suggest that the facile synthesis of CoS2/RGO nanocomposites holds great promise as an electrode material for effective CEs in DSSC applications. [ABSTRACT FROM AUTHOR]

The Fe2O3/NiO nanocomposite was prepared through facile mixing of pure Fe2O3 and NiO nanoparticles. Pure metal oxides were synthesized by the glycine aided hydrothermal method. The crystal structure was determined by X-ray diffraction (XRD) analysis. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) clearly show that the NiO nanospheres were homogeneously distributed on Fe2O3 nanoplates. Fourier transform infrared (FTIR) spectra reveal that functionalization by glycine induces carboxylic and amino groups on the surface of nanoparticles. The optical properties such as light absorption behavior and band gap of the Fe2O3/NiO nanocomposite were determined by UV-Visible diffuse reflectance spectroscopy (DRS UV-Vis). The roxarsone (ROX) sensing behavior of the Fe2O3/NiO nanocomposite was evaluated by using Fourier transform infrared (FTIR) – photoacoustic spectroscopy (PAS) that allowed quantitative sensing of the ROX@Fe2O3/NiO complex. The photoacoustic signals of ROX were clearly observed in the FTIR-PAS spectra, particularly in the range of 1700 to 1000 cm−1 without spectral interference from the composite. Furthermore, principal component analysis (PCA) and partial least square (PLS) regression models were applied to calibrate and validate ROX quantification. The PLS model exhibited the best performance in predicting the ROX concentration through ROX@Fe2O3/NiO samples. This proof of concept suggests that the Fe2O3/NiO nanocomposite has improved adsorption and spectral features by FTIR-PAS for sensing of organometallic compounds such as ROX. [ABSTRACT FROM AUTHOR]