A novel one-pot facile economic approach for the mass synthesis of exfoliated multilayered nitrogen-doped graphene-like nanosheets: new insights into the mechanistic study.

The present research focuses on providing a novel facile, cost-effective and eco-friendly method for the mass production of N-doped graphene-like nanosheets (NGLs), in order to industrially benefit the exploitation of N-doped graphene in electronics, which will lead to the remarkable prosperity of graphene-based nanoelectronics. NGLs have been synthesized through a one-pot single-step process involving hydrolysis/hydrothermal treatment of glucose under mild conditions, using cetyltrimethylammonium bromide (CTAB) and ammonia solution (NH4OH) as the structure-directing agents. NGLs of high yield (65 wt%) and fascinating structural features, including low oxidation level, good crystalline structural order, and large laterally sized and well-exfoliated nanosheets, have been produced. The growth mechanism has been deeply investigated. The impressive chemical nature of CTAB has a synergistic effect in controlling the NGL structure. The cationic head of CTAB and anionic OH- ions resulting from NH4OH ionization have formed a passivating layer that played a profound role in hindering the NGL agglomeration and allowing the NGLs to grow into large lateral dimensions. Meanwhile, the polar (mainly H-bonding) and apolar (hydrophobic) interfacial interactions between the passivating layer and the graphitic network can be mainly considered responsible for the mild disturbed structural order inside the sp2 crystals. On the other hand, the excessive decomposition of CTAB that is also accompanied by fair ammonia decomposition during the hydrothermal treatment resulted in plenty of hydrogen and nitrogen gases in the atmosphere. The nitrogen gas N-doped the graphitic structure and the hydrogen gas effectively deoxygenated it. Furthermore, the high evolution rate of gases throughout the synthesis system contributed to the obstruction of NGL agglomeration. These results emphasize the high yield and good quality of the synthesized NGLs, which makes such a strategy promising in trust acquisition for investors in industrial production of N-doped graphene.

Green synthesis of graphene from recycled PET bottle wastes for use in the adsorption of dyes in aqueous solution.

Polyethyleneterephthalate (PET) is an important component of post-consumer plastic waste. This study focuses on the potential of utilizing "waste-treats-waste" by synthesis of graphene using PET bottle waste as a source material. The synthesized graphene is characterized by SEM, TEM, BET, Raman, TGA, and FT-IR. The adsorption of methylene blue (MB) and acid blue 25 (AB25) by graphene is studied and parameters such as contact time, adsorbent dosage were optimized. The Response Surface Methodology (RSM) is applied to investigate the effect of three variables (dye concentration, time and temperature) and their interaction on the removal efficiency. Adsorption kinetics and isotherm are followed a pseudo-second-order model and Langmuir and Freundlich isotherm models, respectively. Thermodynamic parameters demonstrated that adsorption of dye is spontaneous and endothermic in nature. The plastic waste can be used after transformation into valuable carbon-based nanomaterials for use in the adsorption of organic contaminants from aqueous solution.

Construction of attapulgite decorated cetylpyridinium bromide/cellulose acetate composite beads for removal of Cr (VI) ions with emphasis on mechanistic insights.

Eco-friendly and renewable composite beads were constructed for efficient adsorptive removal of Cr (VI) ions. Attapulgite (ATP) clay decorated with cetylpyridinium bromide (CPBr) was impregnated into cellulose acetate (CA) beads, which were formulated through a simple and cost-effective solvent-exchange approach. FTIR, XRD, SEM, Zeta potential, and XPS characterization tools verified the successful formation of ATP-CPBr@CA beads. The composite beads displayed a spherical and porous shape with a positively charged surface (26.6 mV) at pH 2. In addition, higher adsorption performance was accomplished by ATP-CPBr@CA composite beads with ease of separation compared to their components. Meanwhile, equilibrium isotherms pointed out that the Langmuir model was optimal for describing the adsorption process of Cr (VI) with a maximal adsorption capacity of 302 mg/g. Moreover, the D-R isotherm model verified the physical adsorption process, while adsorption data obeyed the pseudo-second-order kinetic model. Further, XPS results hypothesized that the removal mechanism involves adsorption via electrostatic interactions, redox reaction, and co-precipitation. Interestingly, the ATP-CPBr@CA composite beads reserved tolerable adsorption characteristics with a maximum removal present exceeding 70% after reuse for seven successive cycles, proposing its feasible applicability as a reusable and easy-separable candidate for removing heavy metals from aquatic bodies.

Unveiling the exceptional synergism-induced design of Co-Mg-Al layered triple hydroxides (LTHs) for boosting catalytic activity toward the green synthesis of indol-3-yl derivatives under mild conditions.

The current study provides a novel insight into the role of synergism of the changes in Mg2+/ Al3+ in the best catalytic activity of indol-3-yl derivatives. A series of Co-Mg-Al layered triple hydroxides (LTHs) catalysts were produced by altering the Al3+/Mg2+ ratio with respect to Co2+. The physicochemical properties of LTHs were well characterized by ICP-AES, XRD, FTIR, FE-SEM, BET, Zeta-sizer, and VSM. The results show that the sample CMA4 (Co2+:Mg2+:Al3+ 2:4:4) is an exception to the physicochemical characteristics of the produced Co-Mg-Al LTHs, which is due to the synergism between the changes in Mg2+ and Al3+. To the best of our knowledge, this is the first study to report the synthesis of indol-3-yl derivatives from indole-3-carbaldehyde using Co-Mg-Al LTHs as highly efficient heterogeneous catalysts, which is an extremely appealing path. The selectivity of the synthesis was studied by condensing various nucleophiles through the one-pot method that established superior reactivity under mild conditions. Notably, the results show that the Co-Mg-Al LTHs system exhibited an extraordinarily catalytic activity, with the highest yield (98%) being obtained under the following optimal conditions: the concentration of Co-Mg-Al LTHs = 5 mol%, 30 min., water/ethanol as solvent. Furthermore, the reusable studies exhibited that the catalysts were found to be stable and reusable for up to six cycles without substantial loss of catalytic activity. Finally, a plausible reaction mechanism of the Co-Mg-Al LTHs system for indol-3-yl derivatives was put forward according to our comprehensive analysis. Our work illuminates a cheap and flexible strategy for the synthesis of indol-3-yl derivatives using Co-Mg-Al LTHs.

Electrospun cellulose acetate nanofiber incorporated with hydroxyapatite for removal of heavy metals.

Due to the negative impact of the heavy metal ions in water, the rejection of these toxic materials is one of the urgent requests for wastewater treatment. This work aims to facile fabrication and characterization of new organic/inorganic hybrid nanofiber membrane composites for removal of Fe (III) and Pb (II) ions using a batch technique. The manufacturing of pure cellulose acetate nanofibers (CA NFs) and its impregnated with hydroxyapatite (CA/HAp) nanocomposite fibers is explored by an electrospinning process. A production process of uniform and bead-free nanofiber is developed by adjusting various electrospinning conditions. The experiments prove that the slight changes in operating parameters may result in significant variations in the fiber morphology. The influence of various adsorption conditions and its effect on the removal efficiency is investigated. High separation efficiency of about 99.7 and 95.46% within 35 and 40 min. for adsorption Pb (II) and Fe (III) ions using hybrid nanofiber composite, respectively are obtained. The adsorption process was found to obey a pseudo-second-order and Freundlich models. The adsorption mechanism on the CA/HAp composite can be established via ion exchange and surface complexation.

Ciprofloxacin removal using magnetic fullerene nanocomposite obtained from sustainable PET bottle wastes: Adsorption process optimization, kinetics, isotherm, regeneration and recycling studies.

Numerous of pollutants threaten our planet, for instance plastic wastes causes a huge potential risk on the environment in addition to many of emergened pollutants as pharmaceutical residue in aquatic environments which affecting ecological balance and in-turn affecting human health. Accordingly, this research proposed an innovative facile, one-step synthesis of functionalized magnetic fullerene nanocomposite (FMFN) via catalytic thermal decomposition of sustainable poly (ethylene terephthalate) bottle wastes as feedstock and ferrocene as a catalyst and precursor of magnetite. Growth mechanism of FMFN was discussed and batch experiments were achieved to examine its adsorption efficiency in relation to Ciprofloxacin antibiotic. Different adsorption parameters including time, initial Ciprofloxacin concentration, and solution temperature were investigated and optimized using Response Surface Methodology (RSM) model. In addition, a study on the antibiotic adsorption process impact on the organisms of an ecosystem was conducted using E. coli DH5α, and results validated method's efficiency in overcoming problem of appearance of antibiotic-resistant microbes.