Synthesis of mesoporous carbons by leaching out natural silica templates of rice husk

Yeletsky, Petr M.; Yakovlev, V. А.; Melgunov, M. S.; Parmon, Valentin N.

doi:10.1016/j.micromeso.2008.12.025

Cited by 62 publications

(34 citation statements)

References 20 publications

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Section: Resultsmentioning

confidence: 99%

“…Besides that, carbon phase is able to interact with carbonates themselves with microporosity developing, especially in the case of molar ratios of carbonates to SiO 2 more than 1:1 [23]. In whole, carbonate activation leads to obtaining carbons with A BET = 800-1400 m 2 g -1 , possessing porosity shifted to mesopore area [23]. In the case of alkalis, porosity development in the carbons is due to interaction of alkalis both with SiO 2 and carbon phases, but the carbon phase seems to undergo significant reconstruction because of interaction of alkalis with carbon via oxygen-containing surface functional groups.…”

Section: Resultsmentioning

confidence: 99%

“…More detailed information on the preparation of C/SiO 2 composites from RH and their alkali and carbonate activation is represented in [21][22][23].…”

Section: Carbonate and Alkali Activation Of Carbonized Rhmentioning

confidence: 99%

“…However, on the other hand, the presence of silica allows to consider RH as template-containing precursor for the preparation of porous carbons with textural characteristics depending on the template phase properties. In our previous publications [21][22][23], two methods of preparation of porous carbons, from RH carbonized in the fluidized catalyst bed reactor, have been described-with the use of alkalis and carbonates of Na and K.…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Micro–mesoporous carbons from rice husk as active materials for supercapacitors

Lebedeva

Ayupov

Kuznetsov

et al. 2015

Mater Renew Sustain Energy

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Activated carbons were prepared from rice husk carbonized in the fluidized catalysts bed reactor. Using the different activating agents, samples with BET surface area in the range from 540 to 3060 m 2 /g were achieved. Using sodium or potassium carbonates results in the BET surface area up to 1400 m 2 /g. Hydroxides of sodium or potassium yield the samples with the higher BET surface area (up to 3060 m 2 /g). Textural peculiarities of the carbons were studied by the adsorption of nitrogen at 77 K and of carbon dioxide at 273 K. As active materials for supercapacitors, the porous carbon samples were examined by cyclic voltammetry and chronopotentiometry in galvanostatic mode in 1 M H 2 SO 4 as the electrolyte using home-made three-electrode electrochemical glass cell. Gravimetric capacitance of the carbons is linearly proportional to the BET surface area and reaches 230 and 196 F/g at discharge current density of 0.2 and 1 A/g, respectively, for the samples with the highest surface area.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…More detailed information on the preparation of C/SiO 2 composites from RH and their alkali and carbonate activation is represented in [21][22][23].…”

Section: Carbonate and Alkali Activation Of Carbonized Rhmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Micro–mesoporous carbons from rice husk as active materials for supercapacitors

Lebedeva

Ayupov

Kuznetsov

et al. 2015

Mater Renew Sustain Energy

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“…Aktivasi dengan kalium hidroksida menghasilkan karbon aktif dengan luas permukaan sekitar 3000 m 2 .g -1 . Yeletsky et al (2009) menggunakan aktivator kalium karbonat dengan suhu aktivasi 900°C menghasilkan karbon aktif dengan luas permukaan maksimum mencapai 1676 m 2 .g -1 . Aktivasi arang sekam juga dapat dilakukan melalui impregnasi dengan seng klorida yang menghasilkan karbon aktif dengan luas permukaan 1555 m 2 .g -1 (Lu et al, 2009).…”

Section: Pendahuluanunclassified

Aktivasi Arang Sekam Padi Dengan Larutan Natrium Karbonat Dan Karakterisasinya

2015

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Abstrak: Sekam padi merupakan limbah pertanian yang cukup melimpah di daerah penghasil beras sepeti Jawa Barat, sangat potensial untuk dimanfaatkan sebagai sumber karbon karbon aktif yang dapat digunakan untuk adsorben, pendukung katalis dan elektrode. Sampai saat ini telah banyak penelitian pembuatan karbon aktif dari sekam padi namun masih menggunakan metode dan bahan kimia yang kurang ramah lingkungan serta biaya tinggi. Pada penelitian ini aktivasi arang sekam padi dilakukan dengan metode refluks menggunakan larutan natrium karbonat untuk melarutkan silikanya. Tujuan penelitian ini adalah untuk mengetahui pengaruh rasio mol silika dalam arang sekam padi dengan natrium karbonat, waktu refluks, dan suhu kalsinasi terhadap karakteristik karbon aktif yang dihasilkan. Metode yang digunakan adalah pelarutan silika oleh natrium karbonat dengan cara refluks kemudian dikalsinasi. Hasil aktivasi karbon tersebut dikarakterisasi dengan uji kadar abu, XRD, SEM-EDS, dan FTIR. Dari hasil penelitian ini didapatkan kondisi optimum aktivasi arang sekam padi yaitu rasio mol natrium karbonat dengan silika yaitu 1:3, waktu refluks selama 3 jam, dan suhu kalsinasi 900 o C serta karbon yang didapatkan berupa amorf. Keywords: charcoal activation, rice husk charchoal, activated carbon, sodium carbonate PENDAHULUANSalah satu sumber karbon yang melimpah, terbarukan dan murah adalah sekam padi yang merupakan produk samping pada penggilingan padi. Komponen utama dari sekam padi adalah selulosa (38%), hemiselulosa (18%), lignin (22%), dan SiO 2 (19%) (Worasuwannarak et al., 2007). Banyaknya kandungan senyawa karbon dan silika dalam sekam padi sehingga produk kabonisasinya berupa komposit karbon-silika.Bahan karbon berpori telah banyak menarik minat peneliti dalam beberapa tahun terakhir, karena berpotensi untuk digunakan dalam berbagai bidang terutama di sebagai pendukung katalis, elektrode baterai, kapasitor, penyimpan gas dan rekayasa lainnya (Farag et al., 1998; Frackowiak & Beguin, 2001). Karbon aktif dari sekam padi dapat diperoleh melalui proses karbonisasi yang dilanjutkan dengan proses aktivasi. Proses aktivasi arang sekam padi untuk mendapatkan karbon aktif yang luas permukaan tinggi umumnya melalui penghilangan kandungan silika. Guo et al. (2002) (Lu et al., 2009). Pada proses aktivasi tersebut menggunakan basa yang bersifat korosif dan pada suhu tinggi sehingga memerlukan peralatan kualitas khusus sehingga memerlukan biaya tinggi. Karbon aktif dari sekam padi juga dapat diperoleh dengan cara menghilangkan silika yang terkandung dalam sekam padi dengan menggunakan hidrogenfluorida sebelum karbonisasi, kemudian diaktivasi dengan uap air (Deiana et al.,

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The Adhesion of Mica Nanolayers on a Silicon Substrate in Air

Wang

et al. 2020

Adv Materials Inter

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properties render MNLs as a nearly perfect dielectric material that is expected to considerably improve the electron transport properties of Si based microelectronic devices. Previous studies demonstrated that the use of a MNL as the dielectric layer onto a Si substrate doubled the carrier mobility of graphene field effect transistors (FETs) and increased their transconductance several fold. [3] It also improves the gate control capability of carbon nanotubes (CNTs) FETs by suppressing gate leakage current and decreasing subthreshold slope. [4] In particular, MNLs can replace polymers as dielectric media in flexible electronics. [5,6] Compared with polymer insulators, MNLs not only improve the electron transport properties (because of their higher dielectric constant), but also reduce the effect of elastic mismatch because mica and Si have similar mechanical properties. [7] These make MNLs potentially excellent candidates for Si based flexible devices as dielectric components. In most electronic devices, an MNL is mechanically bonded onto a Si substrate. Thus, the adhesion between the MNL and Si substrate determines the reliability and life of the electronic devices. [8] This is especially important for flexible electronic devices with MNLs that frequently experience bending, twisting and stretching. [9] Characterization of the adhesion of MNLs on a flat substrate is challenging. Previous studies often used the atomic force microscopes (AFM) to measure the adhesion. [10] AFM directly measures the adhesive force of a target material with the AFM tip, rather than the adhesion energy that characterizes the adhesion. To evaluate the adhesion energy of graphene on a flat substrate, a blister method was used. [11] However, the sample preparation in the blister method is relatively long, which is not applicable for MNLs because they can be heavily contaminated during a lengthy preparation process. In situ scanning electron microscope (SEM) peeling is a possible alternative, but electron beam irradiation could considerably affect the surface status of MNL samples. [12,13] The peeling method is also inconvenient for characterising the effect of environmental conditions, such as temperature and humidity, on the adhesion that is the important knowledge for MNL based sensor design and development. [14] In our previous work, [15] a bridging method was developed based on nanomanipulation under an optical microscope, with Mica nanolayers (MNL) are a new dielectric material that can improve the electron transport properties of Si based microelectronic devices. However, the mechanical reliability of such devices is not well understood because measurement of the adhesion between an MNL and a Si substrate is insufficiently accurate. The recent work reports a bridging method that is developed based on the linear beam theory and can characterize the adhesion of MNL on a mica substrate in a reasonably accuracy. In this work, the accuracy of the bridging method is improved by using a nonlinear mechanical model. 15 MNL specimens are mea...

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Synthesis of mesoporous carbons by leaching out natural silica templates of rice husk

Cited by 62 publications

References 20 publications

Micro–mesoporous carbons from rice husk as active materials for supercapacitors

Micro–mesoporous carbons from rice husk as active materials for supercapacitors

Aktivasi Arang Sekam Padi Dengan Larutan Natrium Karbonat Dan Karakterisasinya

The Adhesion of Mica Nanolayers on a Silicon Substrate in Air

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