In this study, kaolin waste was functionalized with sulfonic groups to enhance its textural and chemical properties, resulting in a high-performance heterogeneous catalyst. The functionalized material was thoroughly characterized using various techniques, including FTIR, XRD, TGA, BET (N2-physisorption), and TEM-EDX. The incorporation of sulfonic groups introduced active sites that significantly increased the ion exchange capacity, thereby enhancing the catalytic performance. When employed as a catalyst in the acetalization of benzaldehyde, the functionalized kaolin waste achieved a remarkable conversion rate of 98 % under optimized conditions. The successful transformation of kaolin waste into a highly effective catalyst demonstrates its potential for broader applications in green chemistry, particularly in sustainable synthesis. Acetals, the target products, are crucial intermediates in organic synthesis and the pharmaceutical industry. The catalytic process proposed in this study offers an efficient and environmentally friendly approach to acetal formation, advancing the field of heterogeneous catalysis. Additionally, extending the application of this functionalized material to other challenging reactions could further highlight its versatility and potential as a sustainable catalyst in various industrial processes.

Dimorpholinocyclopentenone, being a relevant chemical compound widespread employed in the pharmaceutical industry, can be synthesized by a facile chemically catalyzed conversion reaction between furfural and morpholine. This reaction was investigated in this work by employing a simple, affordable non-noble metal mesoporous Al-SBA-15 with improved catalytic activity and superior product selectivity. The prepared materials shown a mesoporous structure with high pore volume and enlarged surface area, which are impacted by the quantity of aluminium atom incorporated. These differences leading to superior catalytic properties of Al-SBA-15 with a Si/Al ratio of 10.

Addressing the major challenge of global warming by implementing a circular carbon cycle involving CO2 conversion is currently an urgent priority for a more sustainable future. The design of efficient, stable, cheap and eco-friendly systems for such purpose is a remarkable challenge. This study reports an unprecedented metal -free, co -catalyst -free orange peel waste-derived carbon nanodot highly active and selective system for the photoreduction of CO2 into methanol. The waste -derived photocatalyst exhibited a maximum methanol production rate of 416.6 mu molMeOH.gcat -1 .h- 1 and a highly stable methanol production rate of 12.9 mu molMeOH.gcat -1 .h- 1 after 72 h. This work proposes a successful waste -to -fuel strategy that combines the valorization of orange peel waste and CO2 conversion for the synthesis of green methanol.

A simple and efficient synthesis of carbon nanodots (CNDs) was proposed by using hydrochar obtained through hydrothermal carbonization of beer bagasse (BB), a by-product of the beer industry that possesses several appealing advantages as a lignocellulosic source for carbon material synthesis. Raw materials and produced CNDs were characterized by several techniques such as transmission electron microscopy (TEM), X-ray diffraction (XRD), FT-IR, CHNS elemental analysis, diffusion light scattering (DLS), and zeta potential, and the optical properties were studied by spectrofluorophotometry (PL) and UV-vis absorption spectroscopy. The synthesized CNDs exhibited small dimensions, interesting fluorescence behaviour, high stability and remarkable water solubility due to the presence of hydroxyl and carboxyl functional groups. Exploiting these properties, CNDs were employed in the development of highly sensitive fluorimetric and electrochemical probes for heavy metal ions, which are of great concern for human health, aquatic life, and environmental sustainability. Hg2+ and Pb2+ were detected by the fluorimetric probe with a limit of detection of 11.3 nM and 78.8 nM, respectively, while the electrochemical platform allowed the selective and simultaneous detection of heavy metal ions, reaching a detection limit of 124 ng L-1 and 551 ng L-1, respectively for mercury and lead ions with high sensitivity, in the range between 11.4 and 34.1 mu A nM-1 cm-2. Sustainable synthesis of carbon nanodots (CNDs) through a green route - converting beer bagasse, a by-product of the beer industry, into hydrochar via eco-friendly hydrothermal carbonization, and their application for the selective detection of harmful heavy metal ions.

Nitroaromatic compounds (NACs) are a group of organic chemicals containing one or more nitro functional groups attached to an aromatic ring. These compounds are considered emerging pollutants (EPs) in wastewater due to their potential environmental and human health impacts. These NACs can enter wastewater through various sources, including the production and use of explosives, dyes, pesticides, or pharmaceuticals. 4-nitrophenol (4-NP) is considered a priority pollutant due to its toxicity and potential environmental and health hazards. Thus, its removal is crucial. For that purpose, a novel strategy to carry out Zr-MOFs syntheses has been developed employing I-CHEM technology (Impact Continuous flow Heated Mechanochemistry), an improved wet-milling process. The resulting materials have demonstrated efficacy as catalysts in the reduction of 4-NP towards 4-aminophenol (4-AP), a precursor to paracetamol. Notably, the most promising outcomes were achieved with Zr-MOF prepared through continuous flow mechanochemical processes utilizing Zr-methacrylate clusters as precursor (Zr-MOF/2@RL). 4-NP removal was successfully carried out at room temperature, with an outstanding optimal time of removal of 14 min, 30% faster than with synthesized by conventional methodologies. These findings underscore the innovation brought about by the I-CHEM synthetic approach, where more effective collisions are reached, as well as opening avenues for broader applications of MOFs. The wet-mechanochemical procedure not only demonstrates its novelty, but also presents the potential for scalability under continuous flow conditions, further enhancing the feasibility of largescale production.

Carbon dioxide release by human activity is the major cause of global warming. Decreasing the concentration of CO2 in the atmosphere is a challenge that needs to be addressed. In addition to their negative impact on the environment, the availability of petroleum-based fuel is decreasing. The photoconversion of CO2 into so-called green solar fuel is a possible alternative to reduce the quantity of carbon dioxide in the atmosphere aiming the limitation of greenhouse effect. Among the photocatalyst studied for these reactions, the perovskite-based appeared as one of the most promising class of materials. These materials possess unique optoelectronic properties and exhibit significant variability in terms of their dimensionality, structure, morphology, grain size, and tunable band gap, as well as the position of their valence band and conduction band. This review discusses both the classics and innovative perovskite synthesis methods such as solid-state reaction, hydrothermal and solvothermal synthesis, hot injection or chemical precipitation. Then, the use of these materials for the photoreduction of CO2 into fuel such as formic acid, methanol and methane is detailed.

Addressing the CO 2 challenge is mandatory for the well-being of Earth's ecosystem and humanity. CO 2 catalytic hydrogenation is a suitable solution.

Ultradispersed Mo sulfide species on different supports (carbons, SiO2, Al2O3, TiO2) were synthesized via simple preparation techniques. Physical characterizations show that few-atom clusters and single-atom MoSx species are predominant in the catalysts. As compared with MoS2 reference, the coordination numbers of Mo in the ultradispersed catalysts are decreased and the interatomic Mo-S and Mo-Mo distances are shortened. The materials show high specific activity in hydrodesulfurization (HDS), varying in step with MoSx species dispersion, in the sequence: Mo/carbons > Mo/TiO2 > Mo/Al2O3 ≈ Mo/SiO2. Evolution of the Mo species during sulfidation and HDS reaction was studied by means of operando Quick-X-ray absorption spectroscopy (QXAS) at the Mo K edge, assisted by chemometric analysis. The structure of the Mo species and their evolution are different as a function of support. However, the general sulfidation pathway is similar and involves oxysulfide and MoS3-like intermediates, which are further transformed into the MoSx clusters.

This review provides a state-of-the-art summary of distributed zeolite technology, as well as identifying strategies to further promote the absorption of these materials in various areas of study. Zeolites are materials that can be synthesized or found in natural rock deposits a with a basic composition consisting in Al, Si, and O. Zeolite's consideration as a future material is due to many facile synthesis methods to obtain different structures with variations in pore size, surface area, pore volume and physical properties. These methods are developed using the control of relevant synthesis parameters that influences structure formation, such as crystallization temperature, time of aging and/or crystallization, stoichiometric relationships between components of synthesis gel, pH of the medium, and in some cases the type of structure-directing agent. Each method will lead to geometric changes in the framework formation, making possible the formation of typical chemical bonds that are the fingerprint of any zeolitic structure (O-Si-O and Al-O-Si), forming typical acid sites that give specificity in zeolite and allows it to act as a nanoreactor. The specificity is a characteristic that in some cases depends on selectivity, a fundamental property derived of the porosity, mostly in processes that occur inside the zeolite. In processes outside the structure, the surface area is the main factor influencing this property. Moreover, there are many natural sources with adequate chemical composition to be used as precursors. Some of these sources are waste, minimizing the deposition of potential hazardous materials that can be recalcitrant pollutants depending on the environment. Besides its uses as a catalyst, zeolite serves as a support for many bioprocesses; therefore, this review aims to explain relevant aspects in chemical nature, physical properties, main methods of synthesis, main precursors used for synthesis, and relevant applications of zeolites in chemical catalysis and biological processes.

Molybdenum sulfide-based catalysts are widely used forhydrotreatment,hydrogen evolution, and many other reactions. Recently, we demonstratedthat not only the edges of MoS2 slabs but few-atom ultradispersedMoS( x ) clusters also possess high intrinsicactivity. However, the structure and genesis of such ultradispersedspecies remain unknown. Herein, we present a comparative study ofMoS( x ) catalysts ultradispersed on differentsupports (carbons, SiO2, Al2O3, andTiO(2)). Evolution of the Mo species during sulfidation andhydrodesulfurization (HDS) reaction was studied by means of operandoquick X-ray absorption spectroscopy at the Mo K-edge, assisted bychemometric analysis (multivariate curve resolution with alternatingleast squares). Significant differences of the structure of Mo speciesand their temperature evolution as a function of support were observed.The sulfidation pathway involves the formation of oxysulfide and sulfur-richMoS(3)-like intermediates, which are further transformedinto the final MoS x clusters. As comparedwith MoS2 nanoslabs, the coordination numbers of Mo inthe ultradispersed clusters are decreased, and the interatomic Mo-Sand Mo-Mo distances are shortened. Other characterizations,in particular, STEM-ADF, confirm that few-atom clusters and single-atomspecies are predominant in all the catalysts. The materials show highactivity per Mo atom in the HDS of thiophene, varying in steps withMoS( x ) dispersion, as determined from XAS,in the sequence: Mo/carbons > Mo/TiO2 > Mo/Al2O3 & AP; Mo/SiO2.

The Cover Feature shows groundwater contaminated by environmental pollutants and how a sensor modified by an improved waste is helpful to estimate the presence of contaminants in it. The electrochemical sensors are crucial in the technology for the detection of contaminants, thanks to their simplicity and reusability. The eco-friendly Carbon Dots obtained from fruit peels waste by a bottomup electrochemical synthesis are chemically perfect for the purpose. Cover design by C. Michenzi. More information can be found in the Research Article by V. Bressi et al.

CO2 to methanol conversion is an important process for an ecologic and energetic shift, which stimulates the development of active catalysts based on noncritical elements. We have recently reported that Mo atoms anchored on rutile titania nanorods exhibit distinctive performance in methanol synthesis, that is higher activity and methanol selectivity than Mo dispersed on anatase and P25 commercial forms. In this work, for deciphering the origin of the higher performance of rutile, this support is compared to other selected oxides of interest, and Mo/TiO2 catalysts are investigated operando at high pressure by synchrotron X-ray absorption spectroscopy at the Mo K edge combined with chemometric treatments. The main structural change occurs during the reductive activation pretreatment, when Mo-VI species convert to more reduced ones. However, while on anatase titania the active species are mostly MoO2-like clusters, on rutile titania, single Mo atoms are not only more abundant but may also replace surface Ti atoms, which would explain the more stable single-atom dispersion and the rutile-like coordination of Mo as well as the low sensitivity of the latter to the chemical environment and the metal loading. As a result, Mo-doped rutile titania acts as a promising atomically dispersed catalyst for the hydrogenation of CO2 to methanol.

P-type semiconductor SrZr0.1Mn0.4Mo0.4Y0.1O3-delta (SZMMY) is for the first time composited with n-type ZnO to prepare a solid oxide electrolyte used in fuel cell operable at low temperature. Prepared nanocomposite elec-trolyte material is considered as a novel material owing to the results obtained in terms of improved ionic conductivity, power density, and current density at lower operational temperature. The material has been analyzed as well crystalline material with a dual-phase as confirmed by X-Ray Diffraction (XRD). The structural morphology of designed electrolyte materials was characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM), including high-resolution TEM (HR-TEM). The electrochemical impedance spectra (EIS) showed a remarkably lower charge transfer resistance than conventional electrolyte materials. Obtained results illustrated that ionic conductivity increased, which lead to the acceleration of the electrode reactions. Heterostructure nanocomposite SZMMY-ZnO is beneficial to attain a high ionic conductivity due to the suppression of electronic conduction through the p-n junction. The maximum power density was noted as 841 mW cm-2 at 550 degrees C with a maximum current density of 2287 mA cm-2. Based on optical properties through the p-n junction, the internal electronic current was blocked, which further reduced the short circuit problem in the heterostructure. In addition, the performance and lifetime test indicated good stability of the cell at 550 degrees C with a very small degradation loss. The present study suggests that the SZMMY-ZnO is a promising electrolyte for low-temperature-SOFCs development.

An invasive macroalga biomass was valorised by hydrothermal carbonization. The resultant carbonaceous materials exhibited efficient adsorption of hazardous organic pollutants in water due to their favourable physicochemical and textural properties.

Palladium nanoparticles find extensive applications in catalysis in both homogeneously and heterogeneously catalyzed processes. Supporting metal nanoparticles enhances their stability as compared to their unsupported counterparts. The role of catalytic support is increasingly recognized as crucial in determining the behaviour of these materials. However, controlling the deposition and anchoring of palladium nanoparticles remains a significant challenge. This contribution discusses the preparation of straight lines of palladium particles on zinc oxide by wet impregnation. This phenomenon is attributed to the highly stepped morphology of the employed ZnO that created steric anchoring sites to stabilize the metal particles. Palladium-based catalysts were evaluated for the valuable Suzuki-Miyaura cross-coupling reaction. The dispersed Pd/ZnO catalyst achieved a conversion rate of 86% with 100% selectivity, remarkably superior to that of the Pd/Al2O3 and Pd/TiO2 counterparts.

Abstract Carbon dots (CDs) samples were synthesized from orange peel waste (OPW) via a simple and eco‐friendly hydrothermal carbonization (HTC) and electrochemical (EC) bottom‐up synthesis integrated approach. The comprehensive chemical‐physical characterization of CDs samples, carried out by various techniques such as TEM, EDX, XRD, FT‐IR, underlined their morphological and microstructural features. The CDs exhibited attractive electrochemical properties, and thus an electrochemical sensor by modifying a screen printed carbon electrode (CDs/SPCE) for the detection of nitrobenzene (NB) in water was developed. Electroanalytical performances of CDs/SPCE sensor using differential pulse voltammetry (DPV) demonstrated its high sensitivity (9.36 μA μM−1 cm−2) towards NB in a wide linear dynamic range (0.1–2000 μM) and a low limit of detection (LOD=13 nM). The electrochemical sensor also shown high selectivity, long‐term stability, and repeatability. This paper might open the way to a new synergistic HTC‐EC approach for the synthesis of CDs from waste biomass material and their advanced application in highly efficient electrochemical sensors.

The present manuscript describes the use of silk cocoons as a structuring agent for the formation of an iron-based active phase for the controlled oxidation of benzyl alcohol. Different samples were prepared using different calcination temperatures. X-ray diffraction and transmission electron microscopy showed a higher proportion of alpha-Fe2O3 phase and a higher global crystallinity at superior calcination temperature. In terms of catalytic activity, the sample treated at 500 °C presented the highest conversion reaching 47%, with selectivity in benzaldehyde of 75.9%.

Thermokinetics of Biochar production.