scholarly journals Synthesis and characterization of graphene layers from rice husks

2018 ◽  
pp. 12-18
Author(s):  
Makpal Seitzhanova ◽  
Dmitry Chenchik ◽  
Mukhtar Yeleuov ◽  
Zulkhair Mansurov ◽  
Roberto Di Capua ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Rice Husk ◽  
Renewable Resources ◽  
Large Scale ◽  
Low Cost ◽  
Chemical Activation ◽  
Raw Material ◽  
Graphene Layers ◽  
Naoh Solution

In this work, a method of obtaining graphene layers from natural source specifically from rice husk was developed. A rice husk (RH) was used as a raw material, and potassium hydroxide was used as activation agent. The graphene layers were obtained after four successive stages: pre-carbonization, desilication in 1M NaOH solution, chemical activation and exfoliation of the carbonized rice husk (CRH). The obtained samples were studied using Raman spectroscopy, TEM and SEM; the Raman peaks evidenced the presence of graphene multilayers in the sample. A detailed observation of Raman spectroscopy showed that the obtained samples with ratio of 1/4 and 1/5 (RH/KOH) consisted of graphene layers with a high content of amorphous component. The yield of the product was ~ 3% by weight. This study can provide a new way to the large-scale synthesis of low-cost single and multi-layered graphene using rice husk or other renewable resources.

Empirical Equilibrium Study on Rice Husk and Eggshells as Low Cost Bioadsorbent for the Methylene Blue Removal

2014 ◽  
Vol 699 ◽  
pp. 221-226
Author(s):  
Nurul Hanim Razak ◽  
Md. Razali Ayob ◽  
M.A.M. Zainin ◽  
M.Z. Hilwa
Keyword(s):  
Methylene Blue ◽  
Rice Husk ◽  
Low Cost ◽  
Agricultural Waste ◽  
Textile Wastewater ◽  
Blue Dye ◽  
Rice Husks ◽  
Equilibrium Study ◽  
Porosity Characterization

Eggshells and rice husk, two types of notable agricultural waste were used as bioadsorbent to remove Methylene Blue dye (MBD) in aqueous solution. This study was to investigate the performance of these two bioadsorbents in removing MBD. The removal percentage, adsorption capacity, and porosity characterization were examined. The method applied was a physical filtration. UV-VIS Spectrophotometer was used to determine the efficiency of the bioadsorbents in MBD adsorption. The highest removal percentage at the most concentrated MBD were 51% and 98% for eggshells and rice husks respectively. Meanwhile the characterization of rice husks pore size and volume proves that higher adsorptivity towards dye compares to eggshells porosity. It was concluded that the eggshells and rice husks bioadsorbents was successful to treat industrial textile wastewater with rice husks as the most efficient bioadsorbent in removing MBD.

Adsorptive Removal of Pb(II) Ion from Aqueous Solution Using Rice Husk-Based Activated Carbon

2014 ◽  
Vol 875-877 ◽  
pp. 196-201 ◽  
Author(s):  
Mohd Faisal Taha ◽  
Ahmad S. Rosman ◽  
Maizatul S. Shaharun
Keyword(s):  
Aqueous Solution ◽  
Activated Carbon ◽  
Rice Husk ◽  
Low Cost ◽  
Chemical Activation ◽  
Textural Properties ◽  
Activation Process ◽  
Adsorption Studies ◽  
Three Samples ◽  
Equilibrium Data

The potential of rice husk-based activated carbon as an alternative low-cost adsorbent for the removal of Pb (II) ion from aqueous solution was investigated. Rice husk-based activated carbon was preparedviachemical activation process using NaOH followed by the carbonization process at 500°C. Morphological analysis was conducted using field-emission scanning electron microscope /energy dispersive X-ray (FESEM/EDX) on three samples, i.e. raw rice husk, rice husk treated with NaOH and rice husk-based activated carbon. These three samples were also analyzed for their C, H, N, O and Si contents using CHN elemental analyzer and FESEM/EDX. The textural properties of rice husk-based activated carbon, i.e. surface area (253 m2/g) and pore volume (0.17 cm2/g), were determined by N2adsorption. The adsorption studies using rice husk-based activated carbon as an adsorbent to remove Pb (II) ion from aqueous solution were carried out at a fixed initial concentration of Pb (II) ion (150 ppm) with varying adsorbent dose as a function of contact time at room temperature. The concentration of Pb (II) ion was determined by atomic absorption spectrophotometer (AAS). The removal of Pb (II) ion from aqueous solution increased from 35 % to 82 % when the amount of rice husk-based activated carbon was increased from 0.05 g to 0.30 g. The equilibrium data obtained from adsorption studies was found to fit both Langmuir and Freundlich adsorption isotherms.

scholarly journals Facile bottom-up synthesis of partially oxidized black phosphorus nanosheets as metal-free photocatalyst for hydrogen evolution

2018 ◽  
Vol 115 (17) ◽  
pp. 4345-4350 ◽  
Author(s):  
Bin Tian ◽  
Bining Tian ◽  
Bethany Smith ◽  
M. C. Scott ◽  
Qin Lei ◽  
...  
Keyword(s):  
Large Scale ◽  
Field Effect Transistors ◽  
Low Cost ◽  
Pure Water ◽  
Black Phosphorus ◽  
Raw Material ◽  
Bottom Up ◽  
Metal Free ◽  
Wet Chemical Synthesis ◽  
Intense Activity

Few-layer black phosphorus (BP) nanosheets were first reported as a 2D material for the application of field-effect transistors in 2014 and have stimulated intense activity among physicists, chemists, and material and biomedical scientists, driving research into novel synthetic techniques to produce BP nanosheets. At present, exfoliation is the main route toward few-layer BP nanosheets via employing bulk BP as raw material. However, this is a complicated and time-consuming process, which is difficult for the large-scale synthesis of BP nanosheets. Moreover, BP degrades rapidly when exfoliated to nanoscale dimensions, resulting in the rapid loss of semiconducting properties. Here, we report the direct wet-chemical synthesis of few-layer BP nanosheets in gram-scale quantities in a bottom-up approach based on common laboratory reagents at low temperature, showing excellent stability due to partial oxidation of surface. Solvent and temperature are two critical factors, controlling not only the formation of BP nanosheets but also the thickness. The as-prepared BP nanosheets can extract hydrogen from pure water (pH = 6.8), exhibiting more than 24-fold higher activity than the well-known C3N4 nanosheets. Our results reporting the ability to prepare few-layer BP nanosheets with a facile, scalable, low-cost approach take us a step closer to real-world applications of phosphorene including next-generation metal-free photocatalysts for photosynthesis.

Fabrication and characterization of low-cost and green vacuum insulation panels with fumed silica/rice husk ash hybrid core material

2016 ◽  
Vol 107 ◽  
pp. 440-449 ◽  
Author(s):  
Cheng-Dong Li ◽  
Muhammad-Umar Saeed ◽  
Ning Pan ◽  
Zhao-Feng Chen ◽  
Teng-Zhou Xu
Keyword(s):  
Rice Husk ◽  
Fumed Silica ◽  
Rice Husk Ash ◽  
Low Cost ◽  
Core Material ◽  
Vacuum Insulation ◽  
Fabrication And Characterization

The Production of Reduced Graphene Oxide by a Low-Cost Vacuum System for Supercapacitor Applications

2018 ◽  
Vol 930 ◽  
pp. 609-612
Author(s):  
Quezia Cardoso ◽  
Franks Martins Silva ◽  
Ligia Silverio Vieira ◽  
Julio Cesar Serafim Casini ◽  
Solange Kazume Sakata ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Large Scale ◽  
Low Cost ◽  
High Vacuum ◽  
Cost Effective ◽  
Practical Method ◽  
Raw Material ◽  
Vacuum System ◽  
X Ray ◽  
Pump Pressure

Graphene has attracted significant interest because of its excellent electrical properties. However, a practical method for producing graphene on a large scale is yet to be developed. Graphene oxide (GO) can be partially reduced to graphene-like sheets by removing the oxygen-containing groups and recovering the conjugated structure. GO can be produced using inexpensive graphite as the raw material via cost-effective chemical methods. High vacuum and temperature (10−7 mbar and 1100°C, respectively) conditions are well-known to enable the preparation of reduced powder at the laboratory scale. However, a large-scale high vacuum reduction system that can be routinely operated at 10−7 mbar requires considerable initial capital as well as substantial operational and maintenance costs. The current study aims at developing an inexpensive method for the large-scale reduction of graphene oxide. A stainless steel vessel was evacuated to backing-pump pressure (10−2 mbar) and used to process GO at a range of temperatures. The reduction of GO powder at low vacuum pressures was attempted and investigated by X-ray diffraction and Fourier transform infrared spectroscopy. The experimental results of processing GO powder at various temperatures (200–1000°C) at relatively low pressures are reported. The microstructures of the processed materials were investigated using scanning electron microscopy and chemical microanalyses via energy dispersive X-ray analysis.

scholarly journals Porosity Characteristics of Activated Carbons Derived from Olive Oil Wastes Impregnated with H3PO4

2000 ◽  
Vol 18 (4) ◽  
pp. 373-383 ◽  
Author(s):  
Laila B. Khalil ◽  
Badie S. Girgis ◽  
Tarek A.M. Tawfik
Keyword(s):  
Olive Oil ◽  
Activated Carbons ◽  
Bond Cleavage ◽  
Low Cost ◽  
Chemical Activation ◽  
High Capacity ◽  
Acid Catalyst ◽  
Nitrogen Adsorption ◽  
Raw Material ◽  
Nitrogen Adsorption Isotherms

Locally discarded olive oil waste was tested as a potential raw material for the preparation of activated carbons. Chemical activation by impregnation with H3PO4 was employed using acid solutions of varying concentration in the range 30–70% followed by thermal treatment at 500–700°C. The development of porosity was followed from an analysis of the nitrogen adsorption isotherms obtained at 77 K by applying standard BET and t-plot methods. Carbons with low to moderate surface areas (273–827 m2/g) and total pore volumes (0.27–0.69 ml/g), containing essentially micropores with diameters of 8.2 Å up to 12.4 Å were obtained. Increasing the concentration of impregnant led to the development of porosity with the optimum being attained at 60% H3PO4. Phosphoric acid is visualized as acting both as an acid catalyst promoting bond-cleavage reactions and the formation of new crosslinks and also as a reactant which combines with organic species to form phosphate and polyphosphate bridges which connect and crosslink biopolymer fragments. The present study suggests many applications for environmental pollution control, firstly by utilizing accumulating low-cost agricultural by-products and secondly by producing a multi-purpose high-capacity adsorbent useful in the remediation of micropollutants in various water courses.

scholarly journals Preparation and characterization of activated carbon from Amygdalus Scoparia shell by chemical activation and its application for removal of lead from aqueous solutions

2010 ◽  
Vol 8 (6) ◽  
pp. 1273-1280 ◽  
Author(s):  
Sayed Mohammadi ◽  
Mohammad Karimi ◽  
Daryoush Afzali ◽  
Fatemeh Mansouri
Keyword(s):  
Activated Carbon ◽  
Aqueous Solutions ◽  
Low Cost ◽  
Chemical Activation ◽  
Maximum Adsorption Capacity ◽  
Batch Tests ◽  
Amygdalus Scoparia ◽  
Langmuir And Freundlich Equations ◽  
Characterization Of Activated Carbon

AbstractTwo series of activated carbon have been prepared by chemical activation of Amygdalus Scoparia shell with phosphoric acid or zinc chloride for the removal of Pb(II) ions from aqueous solutions. Several methods were employed to characterize the active carbon produced. The surface area was calculated using the standard Brunauer-Emmet-Teller method. The microstructures of the resultant activated carbon were observed by scanning electron microscopy. The chemical composition of the surface resultant activated carbon was determined by Fourier transform infrared spectroscopy. In the batch tests, the effect of pH, initial concentration, and contact time on the adsorption were studied. The data were fitted with Langmuir and Freundlich equations to describe the equilibrium isotherms. The maximum adsorption capacity of Pb(II) on the resultant activated carbon was 36.63 mg g−1 with H3PO4 and 28.74 mg g−1 with ZnCl2. To regenerate the spent adsorbents, desorption experiments were performed using 0.25 mol L−1 HCl. Here we propose that the activated carbon produced from Amygdalus Scoparia shell is an alternative low-cost adsorbent for Pb(II) adsorption.

Characterization of graphene layers by Kelvin probe force microscopy and micro-Raman spectroscopy

2013 ◽  
Vol 10 (7-8) ◽  
pp. 1172-1175 ◽  
Author(s):  
A. N. Nazarov ◽  
S. O. Gordienko ◽  
P. M. Lytvyn ◽  
V. V. Strelchuk ◽  
A. S. Nikolenko ◽  
...  
Keyword(s):  
Raman Spectroscopy ◽  
Kelvin Probe Force Microscopy ◽  
Kelvin Probe ◽  
Graphene Layers ◽  
Force Microscopy ◽  
Micro Raman Spectroscopy

scholarly journals Pemantapan Proses Sintesis Ligan Dibutilditiokarbamat (DBDTK) Sebagai Pengekstrak Logam Tanah Jarang Berdasarkan Desain Eksperimen

2018 ◽  
Vol 14 (1) ◽  
pp. 195
Author(s):  
Diana Hendrati ◽  
Erianti Siska Purnamasari ◽  
Syulastri Effendi ◽  
Santhy Wyantuti
Keyword(s):  
Rare Earth ◽  
Experimental Design ◽  
Rare Earth Elements ◽  
Contrast Agent ◽  
Design Of Experiment ◽  
Large Scale ◽  
Carbon Disulphide ◽  
Raw Material ◽  
Ligand Synthesis

<p>Gadolinium (Gd) merupakan salah satu logam tanah jarang, dimana logam tanah jarang dapat diekstrak dari mineral salah satunya mineral monasit. Logam Gd biasanya digunakan sebagai bahan dasar <em>contrast agent</em> dalam dunia kesehatan. Ligan dibutilditiokarbamat mampu membentuk senyawa kompleks dengan cara mengikat logam sehingga membentuk khelat yang dapat digunakan untuk ekstraksi. Tujuan dari penelitian ini adalah memantapkan sintesis ligan dibutilditiokarbamat berdasarkan desain eksperimen dan karakterisasi kompleks antara Gd(III) dengan ligan dibutilditiokarbamat hasil sintesis. Penelitian ini diawali dengan pembuatan desain eksperimen untuk sintesis ligan dan ekstraksi Gd(III) dengan ligan, kemudian proses sintesis dan ekstraksi dilakukan sesuai dengan desain eksperimen, hasil sintesis dan ekstraksi dikarakterisasi menggunakan metode spektroskopi serta diuji kelarutannya dalam pelarut organik. Data yang diperoleh menunjukkan bahwa sintesis ligan dibutilditiokarbamat optimal pada suhu 4 °C, perbandingan dibutilamin dan karbondisulfida yaitu 1 : 3 dengan perbandingan mol ammonia terhadap dibutilamin yaitu 1 : 4, sedangkan kondisi optimal untuk ekstraksi Gd(III) dengan ligan yaitu pada pH 6, dengan perbandingan mol Gd(III) dan ligan yaitu 1 : 4 dan lama ekstraksi 60 menit. Oleh karena itu ligan dibutilditiokarbamat hasil sintesis berpotensi digunakan sebagai ekstraktan untuk ekstraksi Gd(III). Hasil prediksi ligan berdasarkan desain eksperimen yaitu sebesar 56,12% sedangkan prediksi ekstraksi Gd(III) dengan ligan hasil sintesis diperoleh sebesar 78,41%. Kesimpulan dari penelitian ini bahwa sintesis ligan dibutilditiokarbamat  berdasarkan desain eksperimen dapat dikembangkan untuk sintesis skala besar.</p><p>Gadolinium (Gd) is one of the rare-earth elements, whereas rare-earth elements can be extracted from monazite. Gd is usually used as raw material for synthesizing contrast agent<em> </em>in medicine field. Dibuthyldithiocarbamate ligand can form a complex compound with metal. This ligand will bind a metal and then forming chelate which is used for extraction. The purpose of this research is to ensure procedure of dibuthyldithiocarbamate ligand synthesis based on the design of experiment and to study the characterization of reaction result between Gd(III) and dibuthyldithiocarbamate ligand which this ligand is synthesis result. This research begins with making design of experiment for ligand synthesis and Gd(III) extraction with ligand, then perform the process of synthesis and extraction according to the design of experiment, the result of synthesis and extraction were characterized by spectroscopy method and solubility tested in organic solvent. The data was collected indicate that the optimal condition of dibuthyldithiocarbamate ligan synthesis at 4 °C (temperature), the ratio of di-n-butylamine and carbon disulphide is 1:3 with the mole ratio of ammonia to the di-n-butylamine 1:4, while the optimal conditions for gadolinium extraction with ligand at pH 6, the mol ratio of gadolinium and ligand is 1:4 and 60 minutes extraction time. Hence, dibuthyldithiocarbamate ligand can be used as extractan for extracting Gd(III). The prediction of ligand based on the experimental design is 56.12% while the prediction of Gd(III) extraction with ligand of the synthesis result is obtained equal to 78.41%. The conclusion of this research is that the synthesis of dibuthyldithiocarbamate ligand based on the experimental design can be developed for large-scale synthesis.</p>

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