Amal Bouich

Phosphate glasses with the following compositions 60P2O5 – 15ZnO – 15CaCO3 – 10Li2CO3 (PZCL) and 60P2O5 – 15ZnO – 15CaCO3 – 10V2O5 have been synthesized by melt quenching method. The prepared glasses were characterized by using X-ray powder diffraction (XRD), Raman spectroscopy, Scanning Electron Microscopy (SEM) and Electrochemical impedance spectroscopy (EIS). X-ray diffraction indicates that all samples have an amorphous structure. Raman analysis confirms that PZCL behaves as a typical alkali-modified ultraphosphate glass rich in Q2 units, whereas PZCV contains characteristic V–O vibrational modes indicating that vanadate groups are integrated into the phosphate backbone. SEM observations show that both PZCL and PZCV phosphate glasses exhibit predominantly amorphous structures, with PZCL presenting a smooth and homogeneous surface while PZCV displays a slightly rougher morphology characterized by uniformly dispersed granular surface features. EIS analysis reveals that the free charge carrier contribution appears as a step in M′(ω,T) and a peak in M″(ω,T), allowing a clear distinction between conductivity relaxation and interfacial polarization or dipolar effects, with conductivity derived from the M″(ω,T) peak frequency. PZCV shows conductivity approximately one order of magnitude higher than PZCL, reaching values of 1.25×10−9 S·cm−1 at 120 °C. The temperature dependence follows Arrhenius behavior, with activation energies of ~87 kJ·mol−1 for PZCV and up to ~103 kJ·mol−1 for PZCL, confirming more efficient ion transport in the vanadium-containing glass. Capacitance analysis reveals a slight increase with temperature for both samples, with PZCV consistently showing higher values (~7 pF) than PZCL indicating an enhanced dielectric response making PZCV a promising candidate for solid-state electrolyte applications in energy storage devices.

To enhance the photocatalytic performance of TiO₂ nanotubes (NTs) for the degradation of Amido Black as an organic pollutant, electrodeposition of bismuth vanadate (BiVO₄) nanostructures was successfully applied. The effect of electrodeposited BiVO₄ (25 s, 50 s, 150 s, 250 s), followed by a thermal treatment on TiO₂-NTs, was studied. The structures of the as-prepared samples were characterized by X-ray diffraction (XRD). Morphological behavior was investigated using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), both coupled with EDX. Optical characterizations were performed using photoluminescence and diffuse reflectance spectroscopy. The BiVO₄/TiO₂ NTs sample with 50 s deposition time gave the highest photocatalytic performance for Amido Black degradation, 99.4% after 150 min under UV light. This result has been achieved due to the structure and the optical properties of the sample. The heterojunction of both catalysts showed the synergetic effect on the photocatalytic performance where they remained stable after five cycling runs. Furthermore, quenching tests were conducted and proved that superoxide radicals (O₂^•) are the main active species during photodegradation process.

This review provides a comprehensive synthesis of the coupled effect of temperature and solar radiation on photovoltaic (PV) module performance and lifespan. Although numerous investigations have examined these stressors in themselves, this research addresses their interrelationship and evaluates the way climatic conditions affect short-term performance fluctuation and long-term degradation mechanisms. The assessment consolidates outcomes from model strategies, laboratory tests, and field monitoring studies. Through the presentation of these findings in a narrative form, the paper identifies recurring difficulties in terms of the absence of shared assessment metrics and the low level of standardisation of long-term test regimes. Second, it underlines the importance of predictive modelling and live monitoring as important management tools for coupled stressors. Finally, the review points out research gaps and underscores future research avenues, including ongoing work towards the development of a coupling index, a composite measure being piloted in individual studies, and advancements in materials technology, predictive methodology, and durability testing.

This work focused on the photocatalytic performance enhancement of titanium dioxide (TiO₂) nanotubes decorated by gold nanoparticles. The surface of the nanotubes synthesized using the anodization technique was modified with subsequent deposition of gold nanoparticles (Au-NPs) via electrophoretic deposition. The impact of electrophoretically deposited gold nanoparticles (Au-NPs) on TiO₂ nanotubes, with varying deposition times (5 min, 8 min and 12 min), was investigated in the degradation of amido black (AB) dye. The morphological analysis using scanning electron microscopy (SEM, TESCAN VEGA3, TESCAN Orsay Holding, Brno, Czech Republic) and transmission electron microscopy (TEM, JEM—100CX2, JEOL Japan). revealed a well-organized nanotubular structure of TiO₂, with a wall thickness of 25 nm and an internal diameter of 75 nm. Optical study, including photoluminescence and diffuse reflectance spectroscopy, provided evidence of charge transfer between the Au-NPs and the TiO₂-NTs. Furthermore, the photocatalytic measurements showed that the enhanced photocatalytic activity of the TiO₂-NTs resulted from successful Au deposition onto their surface, surpassing that of the pure sample. This improvement is attributed to the higher work function of gold nanoparticles, which effectively promoted the separation of photogenerated electron–hole pairs. The sample Au-NPs/TiO₂-NTs with a deposition time of 5 min exhibited the best photocatalytic efficiency, achieving an 85% degradation rate after 270 min under UV irradiation. Moreover, the enhancement obtained was also attributed to the plasmonic effect induced by Au-NPs. Kinetic investigations revealed that the photocatalytic reaction followed apparent first-order kinetics, highlighting the efficiency of Au-NPs/TiO₂-NTs as a photocatalyst for dye degradation.

This study evaluates the valorization potential of cocoa pods, mainly sourced from the Sud-Comoé region of Côte d'Ivoire, through controlled thermal pyrolysis to produce biochar. Two experiments were conducted at final temperatures of 331.29 °C and 357.92 °C, yielding biochars with distinct characteristics. The first trial, with a 55% mass yield, produced a biochar with a Lower Heating Value (LHV) of 14.097 MJ/kg, making it suitable for agronomic applications. The second trial, although yielding only 35%, resulted in a higher-energy biochar with an LHV of 22.158 MJ/kg, positioning it closer to high-performance biomasses such as coconut husks (28-32 MJ/kg) and sawdust (18-22 MJ/kg). Processing one ton of cocoa pods is estimated to yield between 350 and 550 kg of biochar, potentially sequestering between 770 kg and 963 kg of CO2. Compared to direct combustion, this approach avoids approximately 1,063 kg of CO2 emissions per ton of biomass processed. Thermodynamic modeling using the Hirn cycle estimated the energy potential between 3.662 and 5.815 kWh per ton, depending on yield and LHV. These findings highlight the effectiveness of moderate-temperature pyrolysis in producing energy-rich biochar and reinforce the potential for sustainable valorization of cocoa pod residues within Côte d'Ivoire's agro-environmental development framework.

Highly crystalline ZnO nanopillars were successfully synthesized using the mist chemical vapor deposition (Mist-CVD) technique. This environmentally friendly and low-cost method operates under atmospheric pressure and low temperatures. By varying the growth temperature from 300C to 500^∘C, we demonstrated control over the structural, optical and morphological properties of ZnO. X-ray diffraction (XRD) analysis confirmed a transition in the preferential growth orientation from (100) to (002) as the temperature increased, with nanopillars showing a highly c-axis orientation at 450^∘C. SEM and AFM analyses revealed vertically aligned, homogeneously distributed nanopillars with high surface roughness, favorable for photocatalytic applications. Optical transmittance decreased with growth temperature, while the bandgap narrowed due to intrinsic defects. These findings highlight the potential of Mist-CVD for producing high-quality ZnO nanostructures tailored for advanced applications.

This study presents a comparative analysis of anodization and hydrothermal techniques for synthesizing TiO₂ nanotubes directly on titanium foil. It emphasizes its advantages as a substrate due to its superior conductivity and efficient charge transfer. Optimized synthesis conditions enable a thorough evaluation of the resulting nanotubes’ morphology, structure, and optical properties, ultimately assessing their photoelectrochemical and photocatalytic performances. Scanning electron microscopy (SEM) reveals differences in tube diameter and organization. An X-ray diffraction (XRD) analysis shows a dominant anatase (101) crystal phase in both methods, with the hydrothermally synthesized nanotubes exhibiting a biphase structure after annealing at 500 °C. UV–Vis and photoluminescence analyses indicate slight variations in band gaps (around 0.02 eV) and recombination rates. The anodized TiO₂ nanotubes, exhibiting superior hydrophilicity and order, demonstrate significantly enhanced photocatalytic degradation of a model pollutant, amido black (80 vs. 78%), and achieve a 0.1% higher photoconversion efficiency compared to the hydrothermally synthesized tubes. This study underscores the potential advantages of the anodization method for photocatalytic applications, particularly by demonstrating the efficacy of direct TiO₂ nanotube growth on titanium foil for efficient photocatalysis.