A novel Mn-based single-atom photocatalyst is disclosed in this study, designed for the dichlorination of alkenes to achieve vicinal dichlorinated products using N-chlorosuccinimide as a mild chlorinating agent, which have widespread applications as pest controlling agents, polymers, flame retardants, and pharmaceuticals. In developing this innovative catalyst, we achieved the atomic dispersion of Mn on aryl-amino-substituted graphitic carbon nitride (f-C3N4). This marks the first instance of a heterogeneous version, offering an operationally simple, sustainable, and efficient pathway for dichlorination of alkenes, including drugs, bioactive compounds, and natural products. This material was extensively characterized by using techniques such as UV-vis spectroscopy, X-ray absorption near-edge structure (XANES), extended X-ray absorption fine structure (EXAFS), high-resolution transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), magic-angle spinning (MAS), and solid-state nuclear magnetic resonance (ssNMR) spectroscopy to understand it at the atomic level. Furthermore, mechanistic studies based on multiscale molecular modeling, combining classical reactive molecular dynamics (RMD) simulations and quantum chemistry (QC) calculations, illustrated that the controlled formation of Cl radicals from the in situ formed Mn-Cl bond is responsible for the dichlorination reaction of alkenes. In addition, gram-scale and reusability tests were also performed to demonstrate the applicability of this approach on an industrial scale.

Lignocellulosics present attractive properties for sustainable water decontamination. Yet, they lack strong interactive functional groups, making their performance low compared to established adsorbents. Previous works generally focused on exhaustive chemical routes aiming at cellulose isolation from lignocellulosics and its functionalization to enhance its adsorption characteristics. Here, we show that the direct functionalization of Giant Reed (Arundo donax L) in benign Diammonium phosphate/urea system affords highly phosphorylated fibers at a high yield. The samples were characterized using SEM, XRD, FTIR, 13C and 31P NMR spectroscopies, conductometric titration, and Zeta-potential measurements to comprehend their morphology, chemistry, and surface properties. The chemical functionalization of Giant Reed (GR) leads to a significant amount of phosphates attached to the fibers, resulting in a charge content of 4.45 mmol·g−1 and a negative surface charge in a wide pH range. Consequently, the adsorption performance of GR increased more than sixtyfold after phosphorylation, reaching adsorption capacities of 365 mg·g−1 for copper ions and 606–1145 mg·g−1 for dyes. Isotherm and kinetic adsorption models identified the mechanisms governing the adsorption process. This study reveals the prospects of a single-step benign chemical functionalization of a fast growing lignocellulosic resource (GR) that yields highly phosphorylated fibers for the removal of wastewater impurities.

A method for the synthesis of benzoic acids from aryl iodides using two of the most abundant and sustainable feedstocks, carbon dioxide (CO₂) and water, is disclosed. Central to this method is an effective and selective electrochemical reduction of CO₂ (eCO₂RR) to CO, which mitigates unwanted dehalogenation reactions occurring when H₂ is produced via the hydrogen evolution reaction (HER). In a 3-compartment set-up, CO₂ was reduced to CO electrochemically by using a surface-modified silver electrode in aqueous electrolyte. The ex-situ generated CO further underwent hydroxycarbonylation of aryl iodides by MOF-supported palladium catalyst in excellent yields at room temperature. The method avoids the direct handling of hazardous CO gas and gives a wide range of benzoic acid derivatives. Both components of the tandem system can be recycled for several consecutive runs while keeping a high catalytic activity.

The transformation of CO₂ into value-added products from an impure CO₂ stream, such as flue gas or exhaust gas, directly contributes to the principle of carbon capture and utilization (CCU). Thus, we have developed a robust iron-based heterogeneous photocatalyst that can convert the exhaust gas from the car into CO with an exceptional production rate of 145 μmol g⁻¹ h⁻¹. We characterized this photocatalyst by PXRD, XPS, ssNMR, EXAFS, XANES, HR-TEM, and further provided mechanistic experiments, and multi-scale/level computational studies. We have reached a clear understanding of its properties and performance that indicates that this highly robust photocatalyst could be used to design an efficient visible-light-mediated reduction strategy for the transformation of impure CO₂ streams into value-added products.

The surface of SBA-15 mesoporous silica was modified by N-hydroxyphthalimide (NHPI) moieties acting as immobilized active species for aerobic oxidation of alkylaromatic hydrocarbons. The incorporation was carried out by four original approaches: the grafting-from and grafting-onto techniques, using the presence of surface silanols enabling the formation of particularly stable O−Si−C bonds between the silica support and the organic modifier. The strategies involving the Heck coupling led to the formation of NHPI groups separated from the SiO₂ surface by a vinyl linker, while one of the developed modification paths based on the grafting of an appropriate organosilane coupling agent resulted in the active phase devoid of this structural element. The successful course of the synthesis was verified by FTIR and ¹H NMR measurements. Furthermore, the formed materials were examined in terms of their chemical composition (elemental analysis, thermal analysis), structure of surface groups (¹³C NMR, XPS), porosity (low-temperature N₂ adsorption), and tested as catalysts in the aerobic oxidation of p-xylene at atmospheric pressure. The highest conversion and selectivity to p-toluic acid were achieved using the catalyst with enhanced availability of non-hydrolyzed NHPI groups in the pore system. The catalytic stability of the material was additionally confirmed in several subsequent reaction cycles.

As a versatile nanomaterial derived from renewable sources, nanocellulose has attracted considerable attention for its potential applications in various sectors, especially those focused on water treatment and remediation. Here, we have combined atomic force microscopy (AFM) and reactive molecular dynamics (RMD) simulations to characterize the interactions between cellulose nanofibers modified with carboxylate or phosphate groups and the protein foulant model bovine serum albumin (BSA) at pH 3.92, which is close to the isoelectric point of BSA. Colloidal probes were prepared by modification of the AFM probes with the nanofibers, and the nanofiber coating on the AFM tip was for the first time confirmed through fluorescence labeling and confocal optical sectioning. We have found that the wet-state normalized adhesion force is approximately 17.87 +/- 8.58 pN/nm for the carboxylated cellulose nanofibers (TOCNF) and about 11.70 +/- 2.97 pN/nm for the phosphorylated ones (PCNF) at the studied pH. Moreover, the adsorbed protein partially unfolded at the cellulose interface due to the secondary structure's loss of intramolecular hydrogen bonds. We demonstrate that nanocellulose colloidal probes can be used as a sensitive tool to reveal interactions with BSA at nano and molecular scales and under in situ conditions. RMD simulations helped to gain a molecular- and atomistic-level understanding of the differences between these findings. In the case of PCNF, partially solvated metal ions, preferentially bound to the phosphates, reduced the direct protein-cellulose connections. This understanding can lead to significant advancements in the development of cellulose-based antifouling surfaces and provide crucial insights for expanding the pH range of use and suggesting appropriate recalibrations.

Lithium-rich, cobalt-free oxides are promising potential positive electrode materials for lithium-ion batteries because of their high energy density, lower cost, and reduced environmental and ethical concerns. However, their commercial breakthrough is hindered because of their subpar electrochemical stability. This work studies the effect of aluminum doping on Li_1.26Ni_0.15Mn_0.61O₂ as a lithium-rich, cobalt-free layered oxide. Al doping suppresses voltage fade and improves the capacity retention from 46% for Li_1.26Ni_0.15Mn_0.61O₂ to 67% for Li_1.26Ni_0.15Mn_0.56Al_0.05O₂ after 250 cycles at 0.2 C. The undoped material has a monoclinic Li₂MnO₃-type structure with spinel on the particle edges. In contrast, Al-doped materials (Li_1.26Ni_0.15Mn_0.61-xAl_xO₂) consist of a more stable rhombohedral phase at the particle edges, with a monoclinic phase core. For this core-shell structure, the formation of Mn³⁺ is suppressed along with the material's decomposition to a disordered spinel, and the amount of the rhombohedral phase content increases during galvanostatic cycling. Whereas previous studies generally provided qualitative insight into the degradation mechanisms during electrochemical cycling, this work provides quantitative information on the stabilizing effect of the rhombohedral shell in the doped sample. As such, this study provides fundamental insight into the mechanisms through which Al doping increases the electrochemical stability of lithium-rich cobalt-free layered oxides.

The phase evolution of Li-rich Li-Mn-Ni-(Al)-O cathode materials upon heat treatments in the air at 900 °C was studied by X-ray and neutron powder diffraction. In addition, the structures of Li_1.26Mn_0.61−xAl_x Ni_0.15O₂, x = 0.0, 0.05, and 0.10, were refined from neutron powder diffraction data. For two-phase mixtures containing a monoclinic Li₂MnO₃ type phase M and a rhombohedral LiMn_0.5Ni_0.5O₂ type phase R, the structures, compositions, and phase fractions change with heat treatment time. This is realized by the substitution mechanism 3Ni²⁺ ↔ 2Li⁺ + 1Mn⁴⁺, which enables cation transport between the phases. A whole-powder pattern fitting analysis of size and strain broadening shows that strain broadening dominates. The X-ray domain size increases with heat treatment time and is larger than the sizes of the domains of M and R observed by electron microscopy. For heat-treated samples, the domain size is smaller for R than for M and decreases with increasing Al doping.

Tannin, after lignin, is one of the most abundant sources of natural aromatic biomolecules. It has been used and chemically modified during the past few decades to create novel biobased materials. This work intended to functionalize for the first time quebracho Tannin (T) through a simple phosphorylation process in a urea system. The phosphorylation of tannin was studied by Fourier transform infrared spectroscopy (FTIR), NMR, inductively coupled plasma optical emission spectroscopy (ICP-OES), and X-ray fluorescence spectrometry (XRF), while further characterization was performed by scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) and thermogravimetric analysis (TGA) to investigate the morphology, composition, structure, and thermal degradation of the phosphorylated material. Results indicated the occurrence of phosphorylation, suggesting the insertion of phosphate-containing groups into the tannin structure, revealing a high content of phosphate for modified tannin (PT). This elevated phosphorus content serves as evidence for the successful incorporation of phosphate groups through the functionalization process. The corresponding PT and T were employed as adsorbents for methylene blue (MB) removal from aqueous solutions. The results revealed that the Langmuir isotherm model effectively represents the adsorption isotherms. Additionally, the pseudo-second-order model indicates that chemisorption predominantly controls the adsorption mechanism. This finding also supports the fact that the introduced phosphate groups via the phosphorylation process significantly contributed to the improved adsorption capacity. Under neutral pH conditions and at room temperature, the material achieved an impressive adsorption capacity of 339.26 mg·g-1 in about 2 h.

This study presents a sequential fractionation of spruce bark employing a flow-through system that enables continuous extraction without the need to change the chamber during the process. Various bark components such as lipophilic extractives, noncellulosic sugars, and lignin were extracted under mild conditions and within short timeframes compared to the batch process. The utilization of the flow-through system enabled efficient extraction without degradation of products that were observed during the batch process. By recirculating the solvents containing extracted components, the solvent/biomass ratio could be reduced considerably, without degradation of the products. The results demonstrate an energy efficient approach to obtaining valuable components from spruce bark, paving the way for a future biorefinery.