Current Research in Green and Sustainable Chemistry最新文献

Atom-economical, eco-efficient, metal- and chemical oxidant-free formation of C–C and C–N bond from C(sp²)−H and C(sp³)−H of arenes toward the direct synthesis of biaryls and anilides or N-benzylamides under mild electro-oxidative conditions is described. The products of C–C and C–N coupling are obtained in up to 88% yields. Aromatic substrates that are oxidized at potentials less positive than +2 V or have bulky bromine or iodine substituents undergo homo-coupling reactions by anodic oxidation to form biaryls or dimers. Aromatic substrates that are difficult to oxidize (E_ox > +2 V) preferentially form anilides and N-benzylamides upon anodic oxidation. The presence of a chlorine substituent on the aromatic ring leads to the formation of both biaryls and anilides during electro-oxidation.

A green method of producing 1H-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives is shown. It makes use of polyfluorinated alcohol as a reusable catalyst/solvent and the Knoevenagel-Michael cyclic condensation mechanism. This procedure complies with green chemistry guidelines. The reactions can be completed in a lot less time and produce products with exceptional yields. Safe reactions are used in this environmentally friendly approach, which eliminates the requirement for column chromatographic separation. It is also simple to create and work up, inexpensive, and cost-effective. Furthermore, green 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) is highly stable and does not significantly change or lose its effectiveness when utilized four more times. Because of this, it's highly helpful for preserving the environment when doing industrial operations.

The world is currently facing significant challenges in reducing the concentration of atmospheric carbon dioxide (CO₂) through scientific methods, primarily by sequestering the CO₂ in the soil. Biochar is a kind of charcoal that is primarily composed of carbon, hydrogen, and oxygen. Due to its aromatic content, biochar can persist in the environment for an extended period and absorb greenhouse gases (GHG). Each year, biochar effectively captures an estimated amount of CO₂ ranging from 1 to 35 gigatons (GtCO₂) and 78 to 477 GtCO₂ over this century. Biochar helps mitigate climate change by sequestering carbon in the soil for extended periods and consequently reducing GHG emissions. This enhances soil fertility, water retention capacity, and nutrient circulation, which promote higher crop yields. Biochar's by-products of biochar can be harvested and used as a renewable energy source. Besides, biochar integration can be effective in waste management strategies that mitigate the challenges of organic waste disposal. Biochar is also an efficient water purification element that favors climate action. Through the application of biochar alteration can be employed to establish carbon credits, and its methods can effectively reduce carbon emissions to an acceptable level. Biochar's unique properties, wide-spread applicability, cost-effectiveness, and trustworthy development prospects demonstrate great potential towards the Sustainable Development Goals (SDG). This review discusses the properties, diverse applications, and social and technical impacts of biochar in the global carbon cycle towards sustainable development goals.

Herein, Ag/TiO₂ nanocomposite was synthesized via a green chemistry approach, which is an eco-friendly, simple, and cost-effective method involving mangosteen pericarp extract as a reducing agent. The as-prepared nanocomposites were characterized using X-ray powder diffraction (XRD), Fourier transformation infrared spectroscopy (FT-IR), UV-Vis spectrophotometer, Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDS), Transmission electron microscopy (TEM), Zeta potential measurement, and nitrogen (N₂) adsorption-desorption analysis. The performance of Ag/TiO₂ nanocomposite was examined by degradation of methylene blue (MB) dye as a model of organic pollutant. The dye degradation using the Ag/TiO₂ nanocomposite containing 45 mM of Ag revealed the high MB degradation, which is 85.77 % after 30 min under dark condition. Furthermore, complete degradation of 96.76 % was achieved after 2 h under visible light irradiation. In contrast, bare TiO₂ only achieved 41.45 % after 30 min dark and 2 h visible light irradiation. This increase in degradation efficiency can be attributed to the adsorption process and the enhanced light absorption resulting from the localized surface plasmon resonance (LSPR) effect of Ag. Therefore, the green-synthesized Ag/TiO₂ nanocomposite has great potential as an integrated adsorbent photocatalyst materials for remediating organic pollutants in dye effluents.

Deep eutectic solvents (DES) have emerged as a promising class of solvents that offer unique properties and applications in various fields. The oxidation of sulfide with readily available oxidants remains a major challenge. Herein, we report a straightforward and efficient approach for selective oxidation of sulfides to sulfones using only DES as a green solvent and catalyst. A variety of sulfides including dialkyl, aryl-alkyl, and diaryl were selectively oxidized to sulfones using H₂O₂ in good to excellent yields at ambient temperature. This method emphasized, organic solvent-free, and acid-free characteristics making it a new, sustainable, and eco-friendly way to realize direct sulfones. The DES showed a stable catalytic performance through consecutive reuses and were recovered and reused for five times without decrease in the reaction yield.

Optimization of nature friendly and consistent developments of the green synthesis of nanoparticles have engrossed encouraged in nanotechnology since of its marvelous incentive in modifying metals into nano size to its probable use for human welfares. The present report reveals the young leaves of Pancratium telanganense was exposed for extra-cellular bio-synthesis of silver nanoparticles (AgNPs) and its antibacterial actions against bacterial pathogens The eco-friendly biosynthesized AgNps optimized then considered by UV spectrum, FTIR, TEM. Then formed AgNPs were confirmed against bacterial test organisms. The young leaves of Pancratium telanganense were establish to be a noble fabricator of AgNPs. Expansion maximizes exhibited absorbance of 420–425 nm at pH-7, 25 °C with 1 mM AgNO3 concentration and 100 mg of leaves powder crude extract. Auxiliary TEM discovered the types of formation of irregular, fine discrete nanoparticles with size ranging between 20 to 35 nm, the FTIR illustrations the bands at 1644 and 153 8 cm⁻¹ consistent to the necessary ambiances of bands of proteins. Antibacterial activities against bacterial pathogens exhibited good results have shown the maximum inhibition zone about 18 mm and 17 mm respectively at 60 μl of AgNps.