ABSTRACT
In this study, natural Algerian kaolin was used as a support and impregnated with nickel at different loading amounts (2 wt.%, 5 wt.%, and 7 wt.%) in order to prepare a supported catalyst. The wet impregnation technique was used in this preparation; nickel oxide (NiO) was the active phase precursor of the catalyst, and the catalysts were designated as follows: 2%, 5%, and 7% Ni/kaolin. These catalysts were put to the test in catalytic wet peroxide oxidation (CWPO) for degrading the organic contaminant malachite green dye (MG). Analytical techniques such as FTIR spectroscopy, X-ray diffraction, BET, and X-fluorescence were used to examine the structure, morphology, and chemical composition of the support and the produced catalysts. Several parameters, including temperature, catalytic dose, metal loading, hydrogen peroxide volume, and kinetic model were systematically investigated. The combination of improved parameters resulted in a significant increase in the catalytic activity, achieving a high removal rate of MG dye of 98.87%.
Subject(s)
Kaolin , Rosaniline Dyes , Catalysis , Oxidation-Reduction , Coloring Agents/chemistryABSTRACT
Organophosphorus chemistry is a broad field with multi-dimensional applications in research area of organic, biology, drug design and agrochemicals. Conventional methods have been adopted extensively to access phosphorylated compounds that rely on the use of toxic, moisture sensitive phosphorylating agents and occur in the presence of oxidants, catalysts, as well as high temperatures and harsh conditions are required for complete transformations. However, recent progress has been made for phosphorylation reactions using electricity to introduce green and sustainable synthetic procedures. These reactions can be performed at mild conditions and proceed with excellent atom economy. Herein, we targeted electrochemical phosphorylation reactions with generation of new bonds such as C(sp3 ) -P, C(sp2 ) -P, O-P, N-P, S-P and Se-P. This review is aimed to offer an overview of recent developments in the synthetic methodology to easy access of organophosphorus compounds using electrochemistry.
ABSTRACT
Numerous applications in the realm of biological exploration and drug synthesis can be found in heterocyclic chemistry, which is a vast subject. Many efforts have been developed to further improve the reaction conditions to access this interesting family to prevent employing hazardous ingredients. In this instance, it has been stated that green and environmentally friendly manufacturing methodologies have been introduced to create N-, S-, and O-heterocycles. It appears to be one of the most promising methods to access these types of compounds avoiding use of stoichiometric amounts of oxidizing/reducing species or precious metal catalysts, in which only catalytic amounts are sufficient, and it represent an ideal way of contributing toward the resource economy. Thus, renewable electricity provides clean electrons (oxidant/reductant) that initiate a reaction cascade via producing reactive intermediates that facilitate in building new bonds for valuable chemical transformations. Moreover, electrochemical activation using metals as catalytic mediators has been identified as a more efficient strategy toward selective functionalization. Thus, indirect electrolysis makes the potential range more practical, and less side reactions can occur. The latest developments in using an electrolytic strategy to create N-, S-, and O-heterocycles are the main topic of this mini review, which was documented over the last five years.
ABSTRACT
Calcium (Ca) batteries are attractive post-lithium battery technologies, due to their potential to provide high-voltage and high-energy systems in a sustainable manner. We investigated herein 1,5-poly(anthraquinonylsulfide) (PAQS) for Ca-ion storage with calcium tetrakis(hexafluoroisopropyloxy)borate Ca[B(hfip)4 ]2 [hfip=OCH(CF3 )2 ] electrolytes. It is demonstrated that PAQS could be synthesized in a cost-effective approach and be processed environmentally friendly into the electrodes. The PAQS cathodes could provide 94â mAh g-1 capacity at 2.2â V vs. Ca at 0.5C (1C=225â mAh g-1 ). However, cycling of the cells was severely hindered due to the fast degradation of the metal anode. Replacing the Ca metal anode with a calcium-tin (Ca-Sn) alloy anode, the PAQS cathodes exhibited long cycling performance (45â mAh g-1 at 0.5C after 1000â cycles) and superior rate capability (52â mAh g-1 at 5C). This is mainly ascribed to the flexible structure of PAQS and good compatibility of the alloy anodes with the electrolyte solutions, which allow reversible quinone carbonyl redox chemistry in the Ca battery systems. The promising properties of PAQS indicate that further exploration of the organic cathode materials could be a feasible direction towards green Ca batteries.