Layer‐Wise Titania Growth Within Dimeric Organic Functional Group Viologen Periodic Mesoporous Organosilica as Efficient Photocatalyst for Oxidative Formic Acid Decomposition

A bridge dimeric organic functional group viologen PMOs synthesized via layer by layer growth on titania (TiO2) has been unprecedently prepared as stable periodic mesoporous organosilica using surfactant under mild acidic conditions. The layer by layer TiO2 incorporation within the prepared organic functional group viologen‐PMO could successfully develop a new type of hybrid photo‐oxidation system for the mineralization of formic acid under sunlight irradiation conditions.The authors are thankful for financial supports (95849156) from Iran National foundation of Science (INSF). The publication has been prepared with support from RUDN University Program 5–100

Magnetically recoverable graphene oxide supported Co@Fe 3 O 4 /L-dopa for C-C cross-coupling and oxidation reactions in aqueous medium

We report the synthesis of inexpensive and environmentally benign cobalt(0) nanoparticles on L-3,4-dihydroxyphenylalanine (L-dopa) functionalized and magnetite (Fe 3 O 4 ) grafted graphene oxide (Co@GO/Fe 3 O 4 /L-dopa) which was fully characterized with different techniques such as Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HR-TEM), X-Ray Photoelectron Spectroscopy (XPS), X-ray Powder Diffraction (XRD), Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), Vibrating Sample Magnetometer (VSM), Carbon Hydrogen Nitrogen (CHN) analysis, Energy Dispersive X-ray (EDX) and Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Graphene oxide was used as the core material due to its mechanical, electrical and thermal properties. In order to avoid the cumbersome process of separation, magnetite nanoparticles were coated over the graphene oxide. After the successful preparation of graphene oxide based magnetic nanoparticles, L-dopa was grafted over Fe 3 O 4 nanoparticles so as to provide firm anchoring agent for cobalt nanoparticles. Finally, cobalt(0) nanoparticles were immobilized on the developed magnetic support. The catalytic efficiency of the synthesized catalyst was tested for Suzuki cross-coupling and oxidation reactions, usually carried out by precious and expensive second and third row transition metals; products were obtained in good to excellent yields. The synthesized catalyst represents an attractive alternative to conventional catalysts for Suzuki cross-coupling and oxidation reactions, and is recyclable up to five runs

Intensified Pb(II) adsorption using functionalized KCC‑1 synthesized from rice husk ash in batch and column adsorption studies

An attempt to investigate the feasibility of 3-aminopropyltriethoxysilane (3-APTES)-functionalized KCC-1 (NH2/KCC-1) prepared from rice husk ash (RHA) for Pb(II) removal was executed. An effective functionalization of fibrous silica nanospheres (KCC-1) by NH3 was confirmed by FTIR analysis. The optimized condition of Pb(II) adsorption in the batch system was at an initial Pb(II) concentration (X1) of 307 mg/L, adsorbent dosage (X2) of 2.43 g/L, and time (X3) of 114 min, with the Pb(II) removal (Y) of 90.1% (predicted) and 91.2% (actual). NH2/KCC-1 can be regenerated by nitric acid (0.1 M) with insignificant decline of Pb(II) removal percentage (adsorption = 91.2–67.3%, desorption = 77.7–51.9%) during 5 cycles adsorption–desorption study. The examination of column adsorption study at a varying flow rate (1–3 mL/min) and bed height (10–20 cm) showed a good performance at a lower flow rate and higher bed height. Both Adam–Bohalt model and Thomas model displayed a good correlation with experimental data. However, Thomas model was more suitable due to the high correlation coefficient, R2 = 0.91–0.99. This study revealed the intensified Pb(II) adsorption using NH2/KCC-1 synthesized from RHA in batch and column adsorption studies

Intensifed Pb(II) adsorption using functionalized KCC‑1 synthesized from rice husk ash in batch and column adsorption studies

An attempt to investigate the feasibility of 3-aminopropyltriethoxysilane (3-APTES)-functionalized KCC-1 (NH2/KCC-1) prepared from rice husk ash (RHA) for Pb(II) removal was executed. An effective functionalization of fibrous silica nanospeheres (KCC-1) by NH3 was confirmed by FTIR analysis. The optimized condition of Pb(II) adsorption in the batch system was at an initial Pb(II) concentration (X1) of 307 mg/L, adsorbent dosage (X2) of 2.43 g/L, and time (X3) of 114 min, with the Pb(II) removal (Y) of 90.1% (predicted) and 91.2% (actual). NH2/KCC-1 can be regenerated by nitric acid (0.1 M) with insignificant decline of Pb(II) removal percentage (adsorption=91.2–67.3%, desorption=77.7–51.9%) during 5 cycles adsorption–desorption study. The examination of column adsorption study at a varying flow rate (1–3 mL/min) and bed height (10–20 cm) showed a good performance at a lower flow rate and higher bed height. Both Adam–Bohalt model and Thomas model displayed a good correlation with experimental data. However, Thomas model was more suitable due to the high correlation coefficient, R2=0.91–0.99. This study revealed the intensified Pb(II) adsorption using NH2/KCC-1 synthesized from RHA in batch and column adsorption studies

Green chemistry and coronavirus

The novel coronavirus pandemic has rapidly spread around the world since December 2019. Various techniques have been applied in identification of SARS-CoV-2 or COVID-19 infection including computed tomography imaging, whole genome sequencing, and molecular methods such as reverse transcription polymerase chain reaction (RT-PCR). This review article discusses the diagnostic methods currently being deployed for the SARS-CoV-2 identification including optical biosensors and point-of-care diagnostics that are on the horizon. These innovative technologies may provide a more accurate, sensitive and rapid diagnosis of SARS-CoV-2 to manage the present novel coronavirus outbreak, and could be beneficial in preventing any future epidemics. Furthermore, the use of green synthesized nanomaterials in the optical biosensor devices could leads to sustainable and environmentally-friendly approaches for addressing this crisis. © 202

Electrochemical activity of Samarium on starch-derived porous carbon: rechargeable Li- and Al-ion batteries

Rechargeable metal-ion batteries are considered promising electric storage systems to meet the emerging demand from electric vehicles, electronics, and electric grids. Thus far, secondary Li-ion batteries (LIBs) have seen great advances in terms of both their energy and their power density. However, safety issues remain a challenge. Therefore, rechargeable Al-ion batteries (AIBs) with a highly reliable safety advantage and active electrochemical performances have gathered intensive attention. However, the common issue for these two metal-ion batteries is the lack of cathode materials. Many advanced electrode materials reported provide greatly enhanced electrochemical properties. However, their inherent disadvantages—such as complicated fabrication procedures, restricted manufacturing parameters, and the requirement of expensive instruments—limits their potential for further applications. In this work, we demonstrate the high electrochemical activity of the lanthanide element, Sm, towards storing charges when used in both LIBs and AIBs. Lanthanide elements are often overlooked; however, they generally have attractive electrochemical properties owing to their unpaired electrons. We employed starch as both a low-cost carbon source and as a three-dimensional support for Sm metal nanoparticles. The composite product is fabricated using a one-pot wet-chemical method, followed by a simultaneous carbonization process. As a result, highly improved electrochemical properties are obtained when it is used as a cathode material for both LIBs and AIBs when compared to bare starch-derived C. Our results may introduce a new avenue toward the design of high-performance electrode materials for LIBs and AIBs.This research was supported by Korea Institute of Science and Technology Future Resource Program (2E29400) and was sponsored by China Scholarship Council (201808260042). Furthermore, the fnancial supports of the Future Material Discovery Program (2016M3D1A1027666) and the Basic Science Research Program (2017R1A2B3009135) through the National Research Foun‑ dation of Korea are appreciated

Nitro group reduction and Suzuki reaction catalysed by palladium supported on magnetic nanoparticles modified with carbon quantum dots generated from glycerol and urea

Glycerol and urea were used as green and cheap sources of carbon quantum dots (CQD) for modifying Fe3O4 nanoparticles (NPs). The obtained CQD@Fe3O4 NPs were used for the stabilization of palladium species and the prepared catalyst, Pd@CQD@Fe3O4, was characterized using various techniques. This magnetic supported palladium was applied as an efficient catalyst for the reduction of aromatic nitro compounds to primary amines at room temperature using very low palladium loading (0.008 mol%) and also for the Suzuki–Miyaura cross-coupling reaction of aryl halides as well as challenging heteroaryl bromides and aryl diazonium salts with arylboronic acids and with potassium phenyltrifluoroborate. This magnetically recyclable catalyst was recovered and reused for seven consecutive runs in the reduction of 4-nitrotoluene to p-toluidine and for ten consecutive runs in the reaction of 4-iodoanisole with phenylboronic acid with small decrease of activity. The catalyst reused in the Suzuki reaction was characterized using transmission electron microscopy, vibrating sample magnetometry and X-ray photoelectron spectroscopy. Using experiments such as hot filtration and poisoning tests, it has been shown that the true catalyst works under homogeneous conditions according to the release–return pathway of active palladium species.Iran National Science Foundation, Grant/Award Number: 95844587; the Generalitat Valenciana, Grant/Award Number: PROMETEOII/2014/017; the Spanish Ministerio de Economía, Industria y Competitividad, Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER, EU), Grant/Award Number: CTQ2016‐81797‐REDC and CTQ2016‐76782‐P; the Spanish Ministerio de Economía y Competitividad (MINECO), Grant/Award Number: CTQ2014‐51912‐REDC and CTQ2013‐43446‐P

Magnetically recyclable catalytic carbon nanoreactors

Multifunctional nanoreactors are assembled using hollow graphitized carbon nanofibers (GNFs) combined with nanocatalysts (Pd or Pt) and magnetic nanoparticles. The latter are introduced in the form of carbon‐coated cobalt nanomagnets (Co@Cn) adsorbed on GNF, or formed directly on GNF from ferrocene yielding carbon‐coated iron nanomagnets (Fe@Cn). High‐resolution transmission electron microscopy demonstrates that Co@Cn and Fe@Cn are attached effectively to the GNFs, and the loading of nanomagnets required for separation of the nanoreactors from the solution with an external magnetic field is determined using UV–vis spectroscopy. Magnetically functionalized GNFs combined with palladium or platinum nanoparticles result in catalytically active magnetically separable nanoreactors. Applied to the reduction of nitrobenzene the multifunctional nanoreactors demonstrate high activity and excellent durability, while their magnetic recovery enables significant improvement in the reuse of the nanocatalyst over five reaction cycles (catalyst loss < 0.5 wt%) as compared to the catalyst recovery by filtration (catalyst loss

Magnetite and Metal-Impregnated Magnetite Catalysts in Organic Synthesis: A Very Old Concept with New Promising Perspectives

Magnetite is a well-known material, with the impregnation of transition metals onto its surface being a very old protocol for preparing catalysts. However, only recently, the combination of both, magnetite and impregnation protocols, have been recognized as a powerful methodology to prepare catalysts. The impregnation protocol, of nearly all transition metals in the magnetite surface, has rendered the first generation of catalysts. These simple catalysts have been used in a very broad range of organic transformations. Thus, simple imine derivative formation or unknown reactions such as the direct cross β-alkylation of primary alcohols, through dehydrogenation, oxidation, addition, hydrogen autotransfer, and multicomponent reactions has been accomplished using these catalysts. In most cases, these catalysts could be just isolated by magnetic decantation and reused several times without a detrimental effect on the initial results. In some cases, the study of the surface of the catalyst by means of several surface characterization techniques has permitted to determine the real species involved in the process and their structural changes within the reaction cycles. Furthermore, the post-modification of the catalysts by reduction or oxidation of the immobilized metal, or by the addition of ligands, has enlarged the applicability of this type of catalysts.This work was supported by the current Spanish Ministerio de Economía y Competitividad (CTQ2011-24151) and by the University of Alicante

Magnetically Separable and Sustainable Nanostructured Catalysts for Heterogeneous Reduction of Nitroaromatics

This review is focused on the strategies and designs of magnetic nanostructured catalysts showing the enhanced and sustainable catalytic performances for the heterogeneous reduction of nitoaromatics. Magnetic catalysts have the benefits of easy recovery and reuse after the completion of the reactions and green chemical processes. Magnetic separation, among the various procedures for removing catalysts, not only obviates the requirement of catalyst filtration or centrifugation after the completion of reactions, but also provides a practical technique for recycling the magnetized nanostructured catalysts. Consequently, discussions will address the methodologies and exemplars for the reusable magnetic composite catalysts. Because the synthesis of ideal magnetic nanostructured catalysts is of primary importance in the development of high-quality sustainable processes, the designs, preparation methods and recyclability of various recoverable magnetic nanostructured catalysts are emphasized. The representative methods and strategies for the synthesis of durable and reusable magnetic nanostructured catalysts are highlighted. The advantages, disadvantages, recyclability and the efficiency of the introduced heterogeneous systems have been explored in the reduction of nitrobenzene derivatives