ChemSusChem最新文献

Elevating the long-wavelength activation of photocatalysts represents a formidable approach to optimizing sunlight utilization. Polythiophene (PTh), although renowned for its robust light absorption and excellent conductivity, is largely overlooked for its potential as a photocatalyst due to the swift recombination of photogenerated charge carriers. Herein, we unveil that the strategic introduction of an aromatic ring containing varying nitrogen content into PTh instigates polarized charge distribution and facilitates the narrowing of the band gap, thereby achieving efficient photocatalytic activities for both hydrogen and hydrogen peroxide generation. Notably, the best sample, PTh-N2, even demonstrates photocatalytic activity in the red light region (600-700 nm). This study offers a promising avenue for the development of polymer photocatalysts with efficient photocatalytic performance for red light-induced photocatalysis.

Life cycle assessment (LCA) was used, next to green chemistry concepts, to compare the full environmental impacts of the epoxidation of a bio-based monomer, which can be used for the synthesis of vitrimers. On a laboratory scale, the synthesis of the monomer can either be done via a petrochemical route or via an enzymatic reaction pathway. Both reaction pathways were initially optimized to minimize the impact of suboptimal routes on the sustainability evaluation. The subsequent assessment of the enzymatic routes shows lower impact factors for most criteria compared to the petrochemical routes. A significant drawback of the enzymatic reaction, however, is its electricity consumption. The yields of the respective reactions also proved to be crucial; realistic changes in yields revealed the petrochemical reaction to be more sustainable in some cases. LCA is therefore a valuable tool for the preliminary evaluation of the developed synthesis pathways and to identify the critical adjustments needed to increase the sustainability of each reaction.

The first successful synthesis of 1,2,3-triazoles using Cyrene^TM as a biodegradable and non-toxic solvent in click chemistry has been developed. In contrast to previous methods, this sustainable approach allows product isolation by simple precipitation in water, eliminating the need for organic solvent extractions and column chromatography purifications, thus minimizing waste consumption while reducing operational costs. The protocol, performed also at gram scale, has broad applicability and versatility, as shown with complex substrates like biologically active coumarins or triazole-linked bifunctional molecules. Finally, this protocol is also amenable to a three-component reaction involving organic halides, terminal acetylenes and sodium azide, thus avoiding the isolation of organic azides, difficult-to-handle species known for their environmental sensitivity.

Inverted perovskite solar cells (IPSCs) utilizing nickel oxide (NiO_x) as hole transport material have made great progress, driven by improvements in materials and interface engineering. However, challenges remain due to the low intrinsic conductivity of NiO_x and inefficient hole transport. In this study, we introduced MoS₂ nanoparticles at the indium tin oxide (ITO) /NiO_x interface to enhance the ITO surface and optimize the deposition of NiO_x, resulting in increased conductivity linked to a ratio of Ni³⁺:Ni²⁺. This interface modification not only optimized energy level but also promoted hole transport and reduced defects. Consequently, IPSCs with MoS₂ modified at ITO/NiO_x interface achieved a champion power conversion efficiency (PCE) of 21.42 %, compared to 20.25 % without modification. Additionally, unencapsulated IPSCs with this interface modification displayed improved stability under thermal, light, humidity and ambient conditions. This innovative strategy for ITO/NiO_x interface modification efficiently promotes hole transportation and can be integrated with other interface engineering approaches, offering valuable insights for the development of highly efficient and stable IPSCs.

Cross-coupling reactions are indispensable for the construction of complex molecular scaffolds. In this work, we developed a sustainable methodology for the cross-coupling reaction of arene thianthrenium salts with aryl boronic acids, which can be effectively realized under mechanochemical conditions. Liquid-assisted grinding (LAG) enabled fast and high-yielding synthesis of a range of biaryls via Pd/RuPhos-catalyzed cross-coupling. The transformation works under ambient temperature and on air. Environmentally friendly solvent 2-methyltetrahydrofurane (Me-THF) was used as a LAG additive. Moreover, the major by-product of the cross-coupling reaction, thianthrene, can be recovered and reused.

Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) based electrolyte is a promising alternative to liquid electrolytes in lithium metal batteries. However, its commercial application is limited by high crystallinity and low Li⁺ ion conductivity. In this study, we synthesized a fluorinated Li-based metal-organic framework (Li-MOF-F) and used it as a filler to address these limitations. The strategy for the Li-MOF-F filler stands out in two main aspects: framework structure for rapid Li⁺ ion transport and F-functional group with electronegativity. The LiO₄ with π-π conjugated dicarboxylate enables the reversible Li intercalation in the lattice structure. The fluorine atoms with electronegativity transform the polymer matrix from non-polar to polar phase and immobilize TFSI^- anions by electrostatic interaction. As a result, the PVDF-HFP electrolyte with Li-MOF-F (LMF-PE) achieves the highest polarity and Li transference number. In Li/Li symmetric cell tests, LMF-PE demonstrates stable Li plating/stripping behavior without dendrites. Additionally, we applied lithium nickel manganese cobalt oxide (NCM) with 94 % Ni content as a cathode material in cell test. LMF-PE cell delivers a high initial discharge capacity of 226.9 mAh g^-1 and 80 % capacity retention after 150 cycles, highlighting its superior cycling performance. These enhancements are attributed to the structural and electrostatic benefits of Li-MOF-F.

Developing high-activity and long-term stable electrocatalysts for electrochemical CO₂ reduction reaction (eCO₂RR) to valuable products is still a challenge. An in-depth understanding of reaction mechanisms and the structure-function relationship is required for the development of an advanced catalytic eCO₂RR system. Herein, a coordination polymer of indium(III) and benzenehexathiol (BHT) was developed as an electrocatalyst (In-BHT) for eCO₂RR to HCOO^-, which displayed an outstanding catalytic performance over the entire pH range. However, experimental results revealed significantly different catalytic pathways in the acid and neutral/alkaline solutions, which are attributed to the influence of redox non-innocent ligands on the rate-determining step (RDS). In the acid solution, the RDS is the formation of *OCOH intermediate through the proton transfer that originates from H₂O in the solution, leading to relatively sluggish kinetics. But in the neutral or alkaline solution, the thiolate groups could be protonated during the catalytic process, and such proton can attack on carbon of absorbed CO₂ via an intramolecular proton transfer, promoting the formation of *OCHO intermediate, resulting in faster kinetics. Our findings revealed the pivotal roles of the redox non-innocent ligands of metal active sites for eCO₂RR, providing a new idea for designing highly efficient electrocatalysts.

Solvent-free techniques have gained considerable attention in recent years due to their environmental advantages and potential to enable chemical reactivities beyond the reach of traditional solution-based methods. Mechanochemistry has emerged as a groundbreaking approach to drive sustainable chemical processes. Despite its promise, some challenges still need to be explored, including the overlooked issue of material leaching during grinding, a phenomenon in which components from milling media or reaction vessels, such as stainless steel, unintentionally alter reaction outcomes. This study investigates the role of metal leaching in reducing arylnitrosamines by using a poorly soluble solid reagent, thiourea dioxide (TDO), focusing on stainless steel vessels. By comparing conventional mechanochemical methods with innovative solvent-free vibratory techniques, we assess the extent of metal contamination and its impact on reaction efficiency. These findings provide new insights into how material leaching influences chemical processes and offer valuable guidance for optimizing these forward-looking and green methodologies.

The removal of heavy metal ions, such as lead (Pb²⁺), from aqueous systems is critical due to their high toxicity and bioaccumulation in living organisms. This study presents a straightforward approach for the synthesis and surface modification of iron oxide nanoparticles (IONPs) for the magnetic removal of Pb²⁺ ions. IONPs were produced via electrosynthesis at varying voltages (10-40 V), with optimal magnetic properties achieved at 40 V resulting in highly crystalline and magnetic IONPs in the gamma-maghemite (γ-Fe₂O₃) phase. IONPs were characterized using various techniques including X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, vibrating sample magnetometry (VSM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). A novel electrochemical method was developed for the silanization of IONPs using tetraethoxysilane (TEOS), (3-mercaptopropyl)trimethoxysilane (MPTMS) and (3-aminopropyl)triethoxysilane (APTES). The resulting silane-modified IONPs were evaluated for the magnetic removal of Pb²⁺ ions, with TEOS-modified IONPs demonstrating superior performance. This material exhibited a high adsorption capacity of 519 mg/g at a Pb²⁺ ion concentration of 300 ppm, and high removal efficiency across a range of Pb²⁺ ion concentrations, attributed to its Fe₂O₃@SiO₂ core-shell structure. This study highlights the potential of the electrochemical synthesis and silanization of nanoparticles for heavy metal remediation in water.

Ultrathin atomic layer deposited ceria films (<20 nm) are capable of H₂ heterolytic activation at room temperature, undergoing a significant reduction regardless of the absolute pressure, as measured under in-situ conditions by near ambient pressure X-ray photoelectron spectroscopy. ALD-ceria can gradually reduce as a function of H₂ concentration under H₂/O₂ environments, especially for diluted mixtures below 10 %. At room temperature, this reduction is limited to the surface region, where the hydroxylation of the ceria surface induces a charge transfer towards the ceria matrix, reducing Ce⁴⁺ cations to Ce³⁺. Thus, ALD-ceria replicates the expected sensing mechanism of metal oxides at low temperatures without using any noble metal decorating the oxide surface to enhance H₂ dissociation. The intrinsic defects of the ALD deposit seem to play a crucial role since the post-annealing process capable of healing these defects leads to decreased film reactivity. The sensing behavior was successfully demonstrated in sensor test structures by resistance changes towards low concentrations of H₂ at low operating temperatures without using noble metals. These promising results call for combining ALD-ceria with more conductive metal oxides, taking advantage of the charge transfer at the interface and thus modifying the depletion layer formed at the heterojunction.