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Salma Ayadh

Publications and source records attributed to Salma Ayadh.

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Improvement of piezocatalytic performance of Na0.5Bi0.5TiO3 perovskite using K doping for efficient Rhodamine B degradation

Piezocatalysis, based on the piezoelectric properties of catalysts, breaks down the barrier between mechanical energy and chemical energy. It describes the use of charges induced by piezoelectricity to assist typical chemical processes while harvesting various forms of mechanical green energy. The performance of piezocatalysis is predominantly governed by the piezoelectric properties of materials. The main aim of this work is to evaluate and analyze the potential of potassium doped sodium bismuth titanate Na0.5-xKxBi0.5TiO3 abbreviated as NKxBT (0, 0.15, 0.20, and 0.25), as a piezocatalyst in the degradation of the organic dye Rhodamine B RhB under ultrasonic vibration. The synthesis of NKxBT nanopowders was conducted using the sol-gel autocombustion method. Coupled structural analysis reveals the presence of an intermediate Morphotropic Phase Boundary (MPB, where two phases coexist) in the optimal NK15BT composition. The piezocatalytic degradation results showed a total piezo-degradation in only 90 min and a rate constant 8 times higher than the undoped NK0BT. The enhanced piezocatalytic activity results from a synergistic effect of MPB presence, reduced particle size, optimal bandgap and high lattice strain. The NK15BT sample also demonstrated good reusability and good mineralization.

cond-mat.mtrl-sci

Enhancement in Magnetic and Magnetocaloric Properties of CoFe2O4 Nanofibers at Lower Temperatures

This research paper investigates new and first insights into the magnetic and magnetocaloric properties of one-dimensional (1D) cobalt ferrite CoFe2O4 (CFO) nanofibers elaborated by sol gel based electrospinning technique, particularly focusing on their behavior at low temperatures for specific applications. The calcined CFO nanofibers microstructural, structural, magnetic, and magnetocaloric properties were explored. The nanofibers (NFs) microstructure, with an average diameter of 210 nm, was examined by scanning and transmission electron microscopies (SEM, TEM). The X-ray diffraction (XRD) of the CFO nanofibers showed a pure cubic close-packed (c.c.p) spinel crystalline structure with the F d 3 -m space group. The Raman spectroscopic studies further confirm the cubic inverse spinel phase. The Magnetic properties were explored as a function of temperature, ranging from 10 to 300 K, a ferromagnetic behaviour was observed with the highest saturation magnetization of 75.87 emu g(-1) and a coercivity of 723 Oe at room temperature. The variation of the magnetic entropy was measured indirectly using the Maxwell approach with an increasing magnetic field. A maximum of Delta(S)=1.71 J K-1 was reached around 32 K. At 180 K, the associated adiabatic temperature change, Delta (Tmax), was 0.93 K, with a large RCP value of 7.58 J kg-1 was measured, which is reasonably high for the corresponding nanoparticles (NPs). This work may suggest that 1D CFO nanofibers offer a promising route for the production of nanostructured magnetic materials, potentially impacting various electronic and electromagnetic device applications at low temperatures.

cond-mat.mtrl-sci