The development of sustainable and high-performance electrode materials is critical to the advancement of next-generation supercapacitors. In this study, wild neem (Azadirachta indica) seed shells (WNS), an abundantagricultural waste, are utilizedas a renewable precursor for the preparation of porous activated carbon. A two-step synthesis procedure, comprising hydrothermal pre-carbonization followed by eco-friendly potassium carbonate (K2CO3) chemical activation was employed to create N self-doped porous activated carbon (WNS). The resultant carbon material has a high specific surface area of 1010.20 m2·g−1, an interconnected micro/mesoporous structure, and enriched surface functionalities, as validated by Brunauer-Emmett-Teller analysis(BET), X-ray photoelectron spectrometry (XPS), and Fourier-transform infrared (FTIR)spectroscopy. Electrochemical evaluation demonstratesexcellent capacitive performance, delivering a high specific capacitance of 320 F·g−1 at 0.5 A·g−1 and capacitance retention of 101% over 5000 charge-dischargecycles in a three-electrode configuration. These results highlight the potential of WNS-derived activated carbon as a cost-effective and sustainable electrode material for supercapacitor applications, contributing to waste valorisation and the development of environmentally friendly energy storage technologies.

Energy storage and conversion is a subject of great and constant attentions because of industrialization increasing and the fossil resources use and their environmental impacts. Since many years, public policies are oriented towards sustainable development strategies and energy storage and conversion technologies are refocused to play an important role in these strategies. Therefore, low-cost, efficient and environmentally friendly electrochemical energy storage devices are widely developed. As an alternative to traditional batteries, sustainable batteries are emerging. Their particularity is defined by the natural abundance of electrode and electrolyte basic materials, their non-toxicity and their biodegradability ensuring a low environmental impact. Beyond ensuring durability, electrochemical performance optimizing strategies of batteries have recently been the subject of several studies. This ranges from material adaptation to the electrode/electrolyte interface engineering in order to better control degradation processes and the ion transport kinetics. This review provides an analysis of recent advances on sustainable batteries based on bio-materials and redox-active organic materials. Particular attention is paid to bio-based conductive gel electrolytes, sustainable electrode materials and interfacial engineering for ionic kinetics improvement during charging and discharging processes. Finally, some challenges of sustainable batteries are identified and orientations are proposed for future researches to make sustainable batteries more efficient while significantly reducing their environmental impact.

Senegal has adopted a local legislative and regulatory framework to protect the environment and achieve sustainable development goals. Different strategies and legal texts are available. The country has also signed many sub-regional regulations and international conventions. Green Chemistry is taken into account in many laboratories at Cheikh Anta Diop University. In national and international research centers, fundamental and applied researches that follow some principles of Green Chemistry are conducted in agriculture, food technology, and the environment. Some projects are also in progress in these domains. In the industry area, even though some environmental regulations are followed, the practice of green chemistry is rather not widespread, because mainly of unfamiliarity and of routine work. However, Senegal benefits from its membership of IUPAC, and participates in major global forums dealing with green chemistry.

Biomass waste derived from jackfruit (Artocarpus heterophyllus) cores is used to fabricate hierarchical porous activated carbon through chemical activation with Iron(III) chloride (FeCl3) and potassium hydroxide (KOH). Jackfruit is an abundant agricultural by-product in tropical regions, including India, Bangladesh, and Sri Lanka. The activated carbon derived from jackfruit provides a sustainable, low-cost, and high-performance alternative to conventional carbon materials for supercapacitors, thereby aligning with waste valorisation strategies. The prepared carbon displays hierarchical porous structures of both micro and mesopore architectures. They are amorphous and contain functional oxygen groups, as confirmed by X-Ray photoelectron spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy (FTIR). A high surface area (1251m2 g-1) was obtained via Brunauer-Emmett-Teller (BET) analysis. The electrochemical performances, via cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge/discharge (GCD) show high specific capacitance of 310 F g-1 at 0.8 A g-1 from GCD, 331 F g-1 at 10 mV s-1 from CV, and a charge transfer resistance of 0.1410 Omega cm2, in three electrode configuration and showing good cycling stability of 87% over 2500 cycles. These results suggest that the activated carbon offers potential application in low-cost and renewable production of carbon materials for supercapacitors applications.

ABSTRACT In this study, we have prepared N and O co‐doped porous carbon from walnut shells and significantly improved its physico‐chemical properties by a two‐step chemical activation approach using ZnCl 2 and KOH. The synergistic effect of ZnCl 2 and KOH activation resulted in a well‐developed hierarchical porous architecture with a high specific surface area (901 m 2 .g −1 ) and abundant O and N functional groups, as confirmed by XPS analysis. These features facilitated efficient ion transport and enhanced charge storage capacity. Tested in a three‐electrode supercapacitor configuration using a 1 M H 2 SO 4 electrolyte, the optimized carbon electrode exhibited a high specific capacitance of 520 F·g −1 at 1 A·g −1 , and outstanding cycling stability over 5000 cycles with a capacity retention greater than 99%. This work presents a sustainable and efficient route to designing high‐performance electrode materials from biowaste for next‐generation energy storage devices.

Heptamolybdates can be considered as molecular oxides of molybdenum. They constitute a family of inorganic molecular clusters exhibiting a wide range of properties and applications. These compounds are notably used in various fields such as catalysis, biology, and medicine. This article aims to study the impact of alkylammonium cations on the electrochemical and photochromic properties of heptamolybdates. The electrochemical study was conducted by cyclic voltammetry in an aqueous sulfuric acid solution, while the photochromic properties were examined under UV irradiation at 365 nm. We observed that the hybrid heptamolybdates can accept electrons and that the presence of organic cations lowers the reduction potentials of the POM compared to those of (NH4)6[Mo7O24]center dot 4H2O. In particular, the compounds obtained by ammonium substitution, namely (C5H16N2)2(NH4)2[Mo7O24]center dot 2H2O (1) and (C2H10N2)3[Mo7O24]center dot 7H2O (2), display photochromic behavior, in contrast to (NH4)6[Mo7O24]center dot 4H2O. These hybrid compounds were synthesized by reflux in an aqueous medium, then characterized by single-crystal X-ray diffraction as well as UV-visible and infrared spectroscopies.

Asymmetric carbonohydrazide-derived Schiff bases have attracted increasing attention owing to their versatile coordination behaviour, tunable electronic properties, and potential applications in catalysis and bioactive metal-complex design. In this work, 1-(2'-hydroxy-3-methoxybenzylidene) -5-(1'-pyridylethylidene) -carbonohydrazide (H₃L²), an asymmetric Schiff base obtained by the condensation of carbohydrazide with o-vanillin and 2-acetylpyridine, was synthesised and comprehensively characterised. The crystal structure, determined by X-ray diffraction analysis, reveals a triclinic system (P-1) stabilised by a network of intra- and intermolecular hydrogen bonds. DFT calculations performed using the 6-31+G(d,p) basis set accurately reproduce the experimental geometric parameters and confirm the conjugated planarity of the molecule. Mulliken population analysis highlights the nucleophilic sites (O, N) as well as the polarisation of hydrogen bonds. The investigation of the frontier molecular orbitals HOMO and LUMO reveals an energy gap of 3.93 eV and a pronounced electrophilic character (ω = 25.55 eV). Global reactivity descriptors, particularly chemical hardness (η = 0.95 eV) and the high dipole moment (13.14 D), indicate moderate reactivity and strong electronic polarization favoring intermolecular interactions. FTIR spectroscopic characterisation is in good agreement with the calculated vibrational frequencies. Electrochemical studies performed by cyclic voltammetry reveal quasi-reversible electron transfer processes involving oxygen and nitrogen atoms, accompanied by remarkable stability in solution. Altogether, these structural, electronic, and electrochemical properties confer particular interest to this ligand as a promising candidate for the synthesis of metal complexes with potential biological or catalytic applications.

Heavy metals are among the most toxic pollutants found in soils. Lead, in particular, is one of these metals that exerts harmful effects on living organisms even at very low concentrations. Therefore, the objective of this study is to assess the level of lead contamination in soils from garage areas. In this work, we collected soil samples from eight different garages, including five bus stations and three mechanical workshops. On each site, we collected a composite sample that we analyzed in order to quantify the lead content using X-ray fluorescence spectrometry (XRF). The XRF device provided the elemental analysis results of each sample in parts per million (ppm). These results highlighted the presence of trace metal elements such as lead (Pb), copper (Cu), chromium (Cr), zinc (Zn), and arsenic (As), as well as other less toxic metals like iron (Fe), molybdenum (Mo), zirconium (Zr), sulfur (S), and tin (Sn). The comparative study of the concentrations found shows a heterogeneous distribution of lead in the soils of the garages, with values ranging from 36.62 to 53.26 ppm. Concentrations are higher in the soils of mechanical workshops than in those of bus stations, with a few exceptions. The most concerning site (S4) shows the maximum lead content of 53.26 ppm, which does not exceed the alert level of 400 ppm set by the US EPA for soils. Thus, the soils do not currently present major health risks for adults, but long-term exposure could negatively affect children living near these areas.

Heavy metallic cations are prevalent in the environment and have detrimental effects on human health and flora. Research into methods for their detection is increasing. Laser-derived graphene electrodes (LDGEs) have gained popularity in electrochemical applications owing to their straightforward preparation, cost-effectiveness, porous structure, high specific surface area, and advantageous electronic properties. In this study, we showed that the fine-tuning of laser beam parameters, such as power and speed, as well as the electrochemical detection parameters, allowed detecting heavy metal ions, specifically Cd2+ and Pb2+, using carefully optimized porous LDGEs, without the need of adding any other metals such as Bi3+. The optimal LDGEs, respectively fabricated with a laser power and speed of 6.4 W and 30 cm s-1 were characterized using electrochemical measurements, digital imaging, scanning electron microscopy, and Raman spectroscopy, confirming the 3D porous structure. The LDGEs were then subjected to square-wave anodic stripping voltammetry for the simultaneous detection of Cd2+ and Pb2+ in a 0.1 M acetate-buffered solution at pH 4. The key metrics for the LDGE-based sensor were as follows: sensitivities of 0.45 (Cd2+) and 0.93 (Pb2+) mu A ppb-1 cm-2, linear ranges spanning from 25 to 1000 ppb (Cd2+) and 10 to 500 ppb (Pb2+), and detection limits of 6.13 ppb (Cd2+) and 2.96 ppb (Pb2+) (at S/N = 3).The electrochemical sensor could simultaneously detect Cd2+ and Pb2+ in real samples, including ore and tap water. This underscores the applicability and versatility of the optimized LDGEs for heavy-metal ion detection in complex environmental matrices.

Biowaste, a plentiful and underutilized resource, has attracted significant attention for its potential application as a sustainable carbon source for application in electrochemical energy storage (EES) devices. This review presents recent progress in biowaste-derived materials for developing carbonaceous electrodes for EES technologies, namely supercapacitors and batteries. The review provides a comprehensive coverage of various biowaste feedstocks and processing methods for transforming biowaste into porous carbons with tailored structures and advantageous properties. Detailed discussions of the electrochemical behaviours of biowaste-derived carbon compounds in EES applications are provided. Biowaste-derived carbon has demonstrated positive results it terms of specific capacitance, rate capability, and cycle life, indicating its viability as a sustainable alternative to conventional carbon sources.

The creation of new conductive organic polymers in novel electrolyte media is needed for technological developments. Although such materials are essential for modern applications, a thorough experimental and theoretical analysis is required to deepen the knowledge of their properties. For the first time, auto-doping and electropolymerization of 4-amino-3-hydroxy naphthalene sulfonic acid (AHNSA) were performed in weakly diluted acetonitrile. Poly(AHNSA) thin films showed electroactivity in the auto-doped state. Density functional theory using the hybrid functional B3LYP was used to compute this molecule's structural, electrical, topological, and vibrational properties. Bond lengths, isotropic Fermi contact couplings, the spin density, as well as steric effects, indicate that the carbon bound to the nitrogen is not the coupling site during electropolymerization. As we proceed from monomer to polymer, the experimental energy band gap (Egap) changes from 0.758 to 0.604, demonstrating the semiconducting behavior of poly(AHNSA). In order to clarify the reaction mechanism and the coupling locations of the radical cations most likely to be involved in polymerization, infrared and NMR spectroscopy measurements were conducted. Poly(AHNSA) is a particularly attractive polymer for the creation of platforms for electronic systems, which need materials that combine the inherent flexibility of polymer materials with high electronic conductivity.

The increasing environmental pollution caused by antibiotics and solid waste presents a dual challenge. Biomassbased remediation strategies offer a promising approach to enhancing the circular economy, yet they remain a significant research challenge. In this study, a biochar with high adsorption capacity and catalytic activity was synthesized from agricultural waste (Guiera senegalensis) for the first time. The resulting biochar (GSBC) was applied in the adsorption and degradation of amoxicillin (AMX) through an advanced oxidation process (AOP) based on peroxymonosulfate (PMS) activation. The combined process (0.9 g/L GSBC/0.01 mM PMS) achieved AMX degradation rates of approximately 95.0 % and 90.0 % within 45 min in distilled and river water, respectively. Mechanistic studies using radical scavengers revealed that AMX removal occurred via both radical (HO center dot, SO4 center dot- and O-2(center dot-)) and non-radical (O-1(2)) pathway. The influence of inorganic salts (Cl-, NO3-, CO32-, SO42- and PO43-) was also evaluated, with SO42- and PO(4)(3-)exerting the greatest inhibitory effects; however, removal efficiency remained around 80 % despite their presence. The GSBC/PMS system was further tested in various real water matrices, including river water, fountain tower water, aquaculture facility water, and tap water, demonstrating comparable efficiency to that observed in pure water, particularly in river water. Phytotoxicity assessments in different matrices also indicated better performance in river water. This study introduces a novel biochar precursor, promotes agricultural waste valorization, and contributes to the development of sustainable wastewater treatment within the framework of the circular economy.

Dimethoate (DMT) is one of the most used organophosphate compounds for plants protection against pests. Because of its toxicity, its trace presence in ecosystems constitutes a threat to the environment. Thus, it becomes more than necessary to develop highly sensitive methods for monitoring dimethoate in food products. On this, a new sensor based on carbon nanotubes modified by diazonium and decorated with copper oxide nanoparticles (f-CNTs@CuO) was chosen for the quantitative detection by Uv–vis spectrophotometry and, at the same time, for the colorimetric recognition of dimethoate. This sensor was characterized using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS). and X-ray Photoelectron Spectroscopy (XPS), which confirmed the formation of f-CNTs@CuO. The presence of copper nanoparticles improves sensitivity and is responsible for the color change during detection. Formal evidence of naked eye detection was confirmed by digital photo images. This sensor presents a unique response and very high selectivity for the analysis of dimethoate compared to other potentially competitive compounds such as malathion, parathion, glucose and calcium ions. The detection limits with the naked eye and by experimental calculation are equal to 50 ppb and 26.1 ppb respectively, and are well below the maximum limit authorized by the EU and China. The applicability of the sensor was successfully verified in cabbage samples with recoveries of 67.8–104.6

Metal trace elements (MTE) are among the most harmful micropollutants of natural waters.Eliminating them helps improve the quality and safety of drinking water and protect human health.In this work, we used mango kernel powder (MKP) as bioadsorbent material for removal of Cr (VI) from water.Uv-visible spectroscopy was used to monitor and quantify Cr (VI) during processing using the Beer-Lambert formula.Some parameters such as pH, mango powder, mass and contact time were optimized to determine adsorption capacity and chromium removal rate.Adsorption kinetics, equilibrium, isotherms and thermodynamic parameters such as ΔG˚, ΔH˚, and ΔS˚, as well as FTIR were studied to better understand the Cr (VI) removal process by MKP.The adsorption capacity reached 94.87 mg/g, for an optimal contact time of 30 min at 298 K.The obtained results are in accordance with a pseudo-second order Freundlich adsorption isotherm model.Finally FTIR was used to monitor the evolution of absorption bands, while Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) were used to evaluate surface properties and morphology of the adsorbent.

This work first investigates the corrosion-inhibiting behavior of montmorillonite K-10 on reinforcing steel. The corrosion-inhibiting power of the clay (Montmorillonite) is determined in a medium HCl (C = 1N) using free corrosion potential monitoring, Tafel potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results of this study showed a satisfactory corrosion-inhibiting efficiency of around 72.665% for the optimum content of 1%. This is due to the presence of a stable oxide layer that protects the metal against corrosion. To validate the concept of montmorillonite as a corrosion inhibitor in repair mortar, we now turn to the influence of montmorillonite on the mechanical properties of mortars in the hardened state. In this part, montmorillonite K-10 is added to the mortar by partial substitution of the cement by 5% and 10% of the cement mass. The aim of this study is to ensure that the addition of this clay to the mortar composition will not have a negative effect on its compressive and flexural strengths. The results of the compression and flexural tests showed that the presence of montmorillonite in the mortar improved flexural and compressive strengths for the different compositions studied.