Instigation of Low Cost, Non-Toxic and Environmentally Benign Binders for Mild Aqueous Zn/MnO2 Systems

2006 ◽  
Vol 973 ◽  
Author(s):  
Shijun Wang ◽  
M. Stanley Whittingham

ABSTRACTThis study focusses on optimizing the parameters of the hydrothermal synthesis to produce iron phosphates for lithium ion batteries, with an emphasis on pure LiFePO4 with the olivine structure and compounds containing a higher iron:phosphate ratio. Lithium iron phosphate (LiFePO4) is a promising cathode candidate for lithium ion batteries due to its high theoretical capacity, environmentally benign and the low cost of starting materials. Well crystallized LiFePO4 can be successfully synthesized at temperatures above 150 °C. The addition of a reducing agent, such as hydrazine, is essential to minimize the oxidation of ferrous (Fe2+) to ferric (Fe3+) in the final compound. The morphology of LiFePO4 is highly dependent on the pH of the initial solution. This study also investigated the lipscombite iron phosphates of formula Fe1.33PO4OH. This compound has a log-like structure formed by Fe-O octahedral chains. The chains are partially occupied by the Fe3+ sites, and these iron atoms and some of the vacancies can be substituted by other cations. Most of the protons can be ion-exchanged for lithium, and the electrochemical capacity is much increased.


2021 ◽  
Author(s):  
Kaihao Wang ◽  
Shuheng Wang ◽  
Dan Meng ◽  
Dong Chen ◽  
Chenzhong Mu ◽  
...  

Abstract For the sake of direct using on the built wooden buildings, a green flame resistance coating comprising sodium polysilicate (SPS) and boric acid was prepared. With weight gain of only 10 wt.%, the treated wood sample (SPS/B-wood) performed improved limiting oxygen index value of 40.3% and passed the V-0 rating in UL-94 test. Additionally, the total heat release, total smoke production and peak carbon monoxide production of SPS/B-wood sample were decreased by 24.5%, 36.0% and 59.4% respectively, compared with that of control wood sample. The residue of SPS/B-wood sample was increased to 54.0% from 18.4% of control wood sample at 800oC in the thermogravimetry analysis. The flame retardant mechanism was suggested that SPS and boric acid formed Si-O-B and Si-O-Si contained structures, isolating the heat and smoke transfer during wood combustion. Notably, NaOH, introduced by the SPS/B coating, catalyzed the lignin to form compact and high-quality char. To conclude, this low-cost and easily-operated coating has a promising future utilizing in the villages with dense wood buildings.


2020 ◽  
Vol 7 (7) ◽  
pp. 200385
Author(s):  
Maryam Kamalzare ◽  
Mohammad Bayat ◽  
Ali Maleki

The development of simple, practical and inexpensive catalysis systems using natural materials is one of the main goals of pharmaceutical chemistry as well as green chemistry. Owing to the ability of easy separation of nanocatalyst, those goals could be approached by applying heterogeneous bionanocatalyst in combination with magnetic nanoparticles. Starch is one of the most abundant natural polymers; therefore, preparing bionanocatalyst from starch is very valuable as starch is largely available and inexpensive. An ecologically benign and efficacious heterogeneous nanocatalyst was prepared based on a biopolymer, and its attributes and morphology were specified by using Fourier transform infrared spectra, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), thermal analysis and vibrating sample magnetometer measurements; followed by studying catalytic behaviour of bionanocomposite in a multicomponent reaction to synthesize of 4H-pyran derivatives. 4H-pyran is extremely valuable in pharmaceutical chemistry, and the development of methods for synthesis of different derivatives of 4H-pyran is momentous. Revealing environmentally benign nature, mild condition, easy work-up, low cost and non-toxicity are some of the advantages of this protocol. Besides, the bionanocomposite was recovered using an external magnetic bar and could be re-used at least six times with no further decrease in its catalytic activity.


2020 ◽  
Vol 12 (12) ◽  
pp. 5062
Author(s):  
Lulit Habte ◽  
Mohd Danish Khan ◽  
Natnael Shiferaw ◽  
Adeeba Farooq ◽  
Mee-hye Lee ◽  
...  

In present work, environmentally benign green aragonite crystals were synthesized from waste chicken eggshells and bivalve seashells through a simple and low-cost wet carbonation method. This method involves a constant stirring of calcium oxide slurry and magnesium chloride suspension in aqueous solution with constraint carbon dioxide injection at 80 °C. The physicochemical properties of the synthesized aragonite were further compared with the aragonite synthesized from commercial calcium oxide. The morphological analysis, such as acicular shape and optimum aspect ratio (~21), were confirmed by scanning electron microscopy. The average crystal size (10–30 µm) and specific surface area (2–18 m2 g−1) were determined by particle size and Brunauer–Emmett–Teller analysis, respectively. Moreover, a schematic crystal growth mechanism was proposed to demonstrate the genesis and progression of aragonite crystal. Green aragonite can bridge the void for numerous applications and holds the potential for the commercial-scale synthesis with eggshells and bivalve seashells as low-cost precursors.


2015 ◽  
Vol 39 (6) ◽  
pp. 4452-4463 ◽  
Author(s):  
Kapil S. Pandit ◽  
Pramod V. Chavan ◽  
Uday V. Desai ◽  
Makarand A. Kulkarni ◽  
Prakash P. Wadgaonkar

Tris-hydroxymethylaminomethane (THAM): a novel, low cost, green catalyst for the synthesis of medicinally important pyrans and pyran-annulated heterocycles.


1996 ◽  
Vol 426 ◽  
Author(s):  
Shalini Menezes

AbstractElectrochemical deposition of CuInSe2 films has been explored as a low-cost alternative to vacuum deposition. A special feature of this approach is that each element or compound may be selectively deposited or dissolved at a specific potential. This approach could further provide an environmentally benign means to recycle CuInSe2 from spent or defective modules. The paper investigates the reaction mechanisms for co-deposition, as well as, removal of CuInSe2. Rotating ring-disk and photoelectrochemical methods probe the formation and dissolution of Se, Cu2Se, In2Se3 and CuInSe2 films and the corrosion of CuInSe2 single crystal. The results provide important insights into the multiple reaction paths leading to the electrosynthesis of CuInSe2 films and new directions for developing an electrochemical recycling scheme for CuInSe2 modules.


Author(s):  
Boumadiene Benlahreche ◽  
Assya Taleb ◽  
Mokhtar B. Lahrech ◽  
Salih Hacini

An efficient and easy procedure is developed for the synthesis of isatin aldazines or bis-Schiff bases of isatin, catalyzed by a proton exchanged Algerian montmorillonite clay (MMT-H+) as green catalyst. The products were obtained in two catalyzed steps under conventional heating in ethanol. Isatin-3-hydrazone obtained from the reaction of isatin with hydrazine monohydrate reacts in the second step with the appropriate aromatic aldehydes to give the desired products in good yields. The main advantages of using this protonated solid non-toxic catalyst in this synthesis are its availability and low cost, the simplicity of its use, the recycling possibilities without significant loss of its catalytic activity and its environmentally benign process. Copyright © 2019 BCREC Group. All rights reserved


2020 ◽  
Vol 13 (6) ◽  
pp. 1568-1592 ◽  
Author(s):  
Ranjusha Rajagopalan ◽  
Yougen Tang ◽  
Chuankun Jia ◽  
Xiaobo Ji ◽  
Haiyan Wang

Organic materials offer a new opportunity to develop high-performance, low-cost, environmentally benign sodium ion batteries. This review provides insights into the different sodium storage mechanisms in various categories of organic materials.


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