With resurgent interest in green hydrogen as a key element in the transition to a renewable-energy economy, developing efficient, earth-abundant, and low-cost catalysts for hydrogen evolution reaction (HER) is becoming increasingly important but is still very challenging. Herein, we report the synthesis of Co-doped Ni3C nanoparticles encapsulated in ultrathin carbon layers (CNCC) by in-situ thermal decomposition of organic-inorganic hybrid as high-performance HER electrocatalysts. Experimental and density functional theory studies evidence that the substantial high-index (113) surfaces in synergy with a few atomic carbon layers contribute significantly to the activity and stability, while the electronic structure of Ni3C is optimized through tuning the Co content to enhance the intrinsic kinetics for HER. The CNCC exhibits excellent HER activities with overpotentials at 10 mA cm−2 (η10) of 102 and 69 mV and Tafel slopes of 74 and 43 mV dec-1 in respective neutral and alkaline media along with a superior stability without noticeable decay up to 100 h. More importantly, the CNCC outperforms the benchmark Pt/C catalyst under high current density (> 38 mA cm-2) in an alkaline electrolyte, showing great potential for practical hydrogen production.
Oxidization and Chain‐Branching Reaction for Recycling HDPE and Mixed HDPE/PP with In‐situ Compatibilization by Ozone‐Induced Reactive Extrusion
High-density polyethylene (HDPE) and isotactic polypropylene (iPP) are widely used in industrial and residential applications due to their low cost and chemical stability, thus their recycling process can contribute to a circular economy. However, both polymers are non-polar materials, and the incompatibility with most other materials leads to substantially inferior properties of blends. In this work, we propose a flexible compatibilization strategy to improve the compatibility of HDPE/iPP blends. Ozone was adopted to induce reactive extrusion for rapid oxidation of HDPE and chain-branching reactions for both HDPE and HDPE/iPP blends. During extrusion process, ozone oxidizes HDPE effectively in a short time and introduces oxygen-containing groups such as carbonyl and ester group, which improves the hydrophilicity. The addition of trimethylolpropane triacrylate (TMPTA) could promote branching reaction and facilitate the formation of HDPE-g-iPP copolymers, which improved the compatibility for HDPE/iPP. As a result, the impact strength of ozone-modified HDPE and HDPE/iPP blends increased by 22% and 82%, respectively, and the tensile strength also increased. This strategy would have potential applications in the field of sorting-free and solvent-free recycling of waste polyolefin plastics.
Machine learning-assisted methods for prediction and optimization of oxidative desulfurization of gas condensate via a novel oxidation system
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The Underlying Catalytic Role of Oxygen Vacancies in Fatty Acid Methyl Esters Ketonization over TiOx Catalysts
Recently, interest in converting bio-derived fatty acid methyl esters (FAMEs) into added-value products has significantly increased. The selectivity of ketonization reaction in the conversion of the FAMEs has significantly hampered the efficiency of this process. Herein, we prepared catalysts with different levels of oxygen vacancies while the crystal phase remained unchanged. The catalyst with the highest level of oxygen vacancy exhibited the maximum selectivity. The density functional theory (DFT) simulation showed an increase in interatomic distances leading to the formation of frustrated Lewis pairs (FLPs) upon the creation of oxygen vacancies. The surface measurements, type and density of acid sites of the catalysts, showed that the Lewis acid sites enhanced the selectivity for ketone production; while Bronsted acid sites increased the formation of by-products. Moreover, the ketone formation rate was directly proportional to acid density. The findings of this research provide a different approach for catalyst design, based on defects engineering and their effect on the surface activity, which could be used for enhancing the catalytic performance of novel metal oxides.
Regulating the Content of Donor Unit in Donor–Acceptor Covalent Triazine Frameworks for Promoting Photocatalytic H2 Production
Using their own triazine groups as natural receptors, the introduction of various donor units to construct donor-receptor configuration in covalent triazine frameworks (CTFs) has been shown to be an effective strategy to improve photocatalytic activity. In this work, the effect of donor unit content (D-content) on the photoelectric properties and photocatalytic activity of CTFs was thoroughly investigated. Four analogous CTFs with different D-content have been rationally designed and synthesized, in which the bithiophene (Btp) as the donor unit and triazine as the acceptor unit. And CTF-Btp with the highest D-content showed the best photocatalytic activity. The experimental and theoretical results indicated this improvement is attributed to stronger visible light absorption capacity and higher photoinduced charge carrier separation efficiency. This study elucidates the relationship between the structural features of CTFs with varying D-content and their photocatalytic activity, offering a promising strategy for developing efficient photocatalysts.
Anthracene appended organotin (IV) compounds: Synthesis, structure elucidation and their cytotoxicity against A549 and RBL cancer cell lines
In vitro, cytotoxicity evaluation of two new anthracene Schiff base triorganotin(IV) compounds are reported. Molecular docking studies suggest their interaction with Hsp90 and NF-κB p65 proteins. One of the compounds demonstrates a notable inhibitory effect on the proliferation of A-549 (lung carcinoma) cells, and has a strong affinity for those proteins.
Two new anthracene Schiff base triorganotin (IV) compounds trimethylstannyl(E)-4-((anthracen-9-ylmethylene)amino)benzoate (1) and triphenylstannyl(E)-4-((anthracen-9-ylmethylene)amino)benzoate (2) were synthesized by mixing trimethylstannyl (or triphenylstannyl) 4-aminobenzoate and 9-anthraldehyde in anhydrous toluene under refluxing conditions. Elemental analysis, FT-IR, 1H-NMR, 119Sn NMR and ESI-MS were used to determine the composition of the compounds. X-ray diffraction analyses revealed the structural details of the compounds. The in vitro cytotoxicity assessment of these compunds was screened against human A-549 (lung carcinoma) and rat RBL (leukemia) cancer cell lines. Both compounds displayed a pronounced in vitro cytotoxic effect on the subjected cancer cell lines. Notably, the proliferation of A-549 cells experienced substantial inhibition in the presence of compound 2. The mode of interaction with Hsp90 and NF-κB p65 proteins responsible for cancer propagation was also assessed by molecular docking. Compounds 1 and 2 bind to the Hsp90 protein with binding energies of −307.65 and −373.45 kcal/mol, respectively, while to NF-κB p65 protein the binding energies are of −329.35 and −395.35 kcal/mol, in the same order. Compound 2 exhibited a significantly high binding affinity to NF-κB p65 and Hsp90 proteins validating our experimental findings from the in vitro experiments.
PolyVinyl alcohol and copper nickel co‐doped titania nanocomposite: Designing, characterization, optical properties, and catalytic application in the synthesis of aryl derivatives of benzothiazole and benzimidazole
This paper reports the design, synthesis, properties, and applications of a nanocomposite material composed of polyvinyl alcohol (PVA) and copper nickel co-doped titanium dioxide (Cu-TiO2-Ni). The material was synthesized using a simple precipitation process, and its properties were characterized using various analytical techniques, including powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry analysis, field emission scanning electron microscopy, and high-resolution tunnelling electron microscopy; BET surface area was investigated. Its application as a catalyst in synthesizing aryl derivatives of benzothiazole and benzimidazoles has been checked.
The paper examines the properties and potential applications of a nanocomposite material composed of polyvinyl alcohol (PVA) and copper nickel co-doped titanium dioxide (Cu-TiO2-Ni). The material was synthesized using a simple precipitation process, and its properties were characterized using various analytical techniques, including powder X-ray diffraction, Fourier transform infrared spectroscopy, thermogravimetry analysis, field emission scanning electron microscopy, and high-resolution tunnelling electron microscopy; Brunauer–Emmett–Teller (BET) surface area was investigated. The results showed that the addition of Cu-TiO2-Ni to PVA improved the material's Ultraviolet–visible spectroscopy (UV) absorption properties. Additionally, the PVA/Cu-TiO2-Ni nanocomposite material exhibited potential for use in a range of applications, including catalysis. Its utility in synthesizing aryl derivatives of benzothiazole and benzimidazoles, which are crucial intermediates in the fine chemical, agrochemical, and pharmaceutical industries and material science, was evaluated. It was found to offer several advantages, including a quick reaction time, simple workup, and good to excellent isolated yields. These characteristics make this protocol both practical and economically intriguing.
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Functionalization of graphitic C3N5 with Pd nanoparticles: An efficient photocatalyst for Suzuki‐Miyaura coupling reaction
Graphitic-carbon nitride system (C3N5) was functionalized with Pd nanoparticles as a result of in situ reduction of Pd2+ through a prepared N-rich system. The obtained composite demonstrates excellent photocatalytic activity in the Suzuki-Miyaura coupling reaction.
Utilizing sunlight as a driving force in chemical reactions is a great benefit for a sustainable future. Metal-based composites are basic components in various catalytic reactions. However, few researches reported carbon nitride-supported Pd nanoparticles in photocatalytic coupling reactions. This study reports the preparation of a graphitic-carbon nitride system (C3N5) followed by modification with various amounts of Pd nanoparticles. The C3N5 was synthesized by thermal deammoniation of melem hydrazine precursor and then modified by Pd cations to create a metallic composite. Regarding the N-rich surface of C3N5, Pd2+ cations are rapidly reduced to Pd nanoparticles in mild conditions, which is strongly supported by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses. Moreover, field emission scanning electron microscopy (FESEM) and high-resolution transmission electron microscopy (HRTEM) analyses clearly depicted the formation of 20 nm Pd nanoparticles on the surface of C3N5. The obtained Pd/C3N5 composite exhibited prominent photocatalytic performance for Suzuki-Miyaura coupling reactions (91% during 25 min at room temperature). This study also compares the effect of various amounts of Pd cation in the progress of Suzuki-Miyaura coupling reactions.
Stabilization and anchoring of palladium‐copper alloy on murexide modified carbon nanotube as a superb nanocatalyst: Excellent performance in coupling and synthetic reactions
Herein, an environmentally benign approach was developed for immobilizing and anchoring Pd-Cu alloy nanoparticles on Murexide (MX) functionalized carbon nanotubes (CNT). Afterward, the catalytic activity of Pd2-Cu3@MX/CNT was studied in synthesizing 2,3-dihydro quinazoline-4(1H)-ones and carbon-carbon coupling reactions at sustainable reaction conditions under ultrasound irradiation. The results demonstrated that high-affinity MX ligand and porous CNT structures than the adsorption of Pd–Cu had a unique designation in the high-range constancy of the alloy nanoparticles and following catalytic activity.
Sketching a proper catalytic system with supplementary attributes, containing easy separation, wide surface area, supreme loading capacity, and fantastical electronic attributes, proposes an encouraging direction for efficiently using nanostructures for various applications. However, the capability to adjust the nano-measure bimetallic particles is an adjustment for attaining superb performance in the catalytic field. Herein, an environmentally benign approach was developed for immobilizing and anchoring Pd-Cu alloy nanoparticles on murexide (MX)-functionalized carbon nanotubes (CNTs). Afterward, the catalytic activity of Pd2-Cu3@MX/CNT was studied in synthesizing 2,3-dihydro quinazoline-4(1H)-ones and carbon–carbon coupling reactions at sustainable reaction conditions under ultrasound irradiation. The results demonstrated that high-affinity MX ligand and porous CNT structures than the adsorption of Pd–Cu had a unique designation in the high-range constancy of the alloy nanoparticles and following catalytic activity. In addition, ultrasound irradiation got electrons of Pd–Cu alloy nanoparticles agitated, constructing a synergic efficacy between Cu and Pd metals for synthesis and coupling reactions. Our study represents that the designed catalyst is green, recyclable, and most suitable, providing new intuition into in high-range constancy of bimetallic nanoparticles for broad applications.