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The oxygen evolution reaction (OER) holds pivotal importance in sustainable energy conversion, as it forms the critical half-reaction in various electrochemical processes, including water splitting for hydrogen production and rechargeable metal-air batteries. Here, a CoFe2O4@Co3O4 nano-composite was synthesized using a facile hydrothermal process and deposited onto the surface of nickel foam through electrophoresis. Characterization using XRD, Raman spectroscopy, and XPS confirmed the successful synthesis of the composite, exhibiting characteristic peaks of both Co3O4 and CoFe2O4. The nano-composite exhibited a more amorphous phase than pure oxides, benefiting electrocatalytic activity. Scanning and transmission electron microscopy highlighted the composite's morphological characteristics, showcasing a Co3O4 island distribution on the CoFe2O4 surface. Electrochemical evaluations revealed the superior oxygen evolution reaction (OER) performance of CoFe2O4@Co3O4, with low overpotentials, faster kinetics, and enhanced stability compared to pure oxides and the benchmark RuO2 catalyst. A comprehensive analysis was carried out to investigate the dynamic behavior during electrocatalytic oxygen evolution reaction. This study unveils the intricate charge and electron transfer mechanisms between cobalt and iron atoms, providing insights into their collaborative role throughout the OER process. [ABSTRACT FROM AUTHOR]

Olive pomace is generated during the production of olive oil. The disposal of olive pomace presents a serious environmental issue to the agricultural community in Morocco. Among all actions devoted to the reduction of olive pomace waste, their revaluation seems to be the most efficient and advantageous from both environmental and economic points of view. Due to its high moisture content, solar drying constitutes an important and promising solution for a possible bio-fuel conversion of olive pomace. For this purpose, a modified uneven-span greenhouse dryer was designed and installed at the faculty of sciences Semlalia, Marrakech, Morocco. An experimental study of solar drying kinetics of the olive pomace was conducted to test the performances of the modified greenhouse dryer under a hybrid (solar/hot air) forced convection mode. The hot-air blower was supplied by electricity from a PV array installed near the greenhouse. The mean temperatures of air within the greenhouse and of the olive waste during the drying hours reached, respectively, 63 °C and 55 °C (from August 3rd to August 5th). The duration of the drying operation of 300 kg of waste from a moisture content of 50 mass% to 19 mass% was 27 h, which was low compared to the open sun drying. Therefore, hybrid forced mode enabled a considerable reduction in drying time, being an aspect to take into account for its use during low solar radiation. The drying kinetics of thin layer two-phase olive pomace was also investigated. The Two-term Gaussian model was found to be the most suitable model to describe the thin layer drying behavior of the two-phase olive pomace dried under hybrid forced convection greenhouse drying mode. In addition, the Fourier series was used to solve the diffusivity equation inside the two-phase olive pomace. The effective diffusivity was found to be 2.0 10–09 m2 s−1 and 2.3 10–09 m2 s−1 using the linear fit and the slope from two successive points methods, respectively. [ABSTRACT FROM AUTHOR]

We have studied the structural, optical, electrical and thermoelectric properties of radio frequency (RF)-sputtered indium tin oxide (ITO) thin films, synthesized at room temperature on glass substrates. A target, containing 90 wt% of In2O3 and 10 wt% of SnO2, was used. The structure of ITO thin films was analyzed by x-ray diffraction (XRD) and x-ray reflectivity (XRR). Moreover, the electrical and optical properties were characterized by the four-point probe method and UV-Vis-NIR spectrometry, respectively. The effect of the RF power on the structural, optical, electrical, and thermoelectric properties showed that the prepared films are suitable as transparent conducting oxides in many applications. [ABSTRACT FROM AUTHOR]