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    Synthesis of Boron Nitride Quantum Dots Using a Mechanical Milling- Solvothermal Process

    , M.Sc. Thesis Sharif University of Technology Angizi, Shayan (Author) ; Simchi, Abdolreza (Supervisor)
    Abstract
    Boron Nitride Quantum Dots, as a new member of Heavy-metal-free Quantum dots has attracted many attention due to their unique properties. The hyroxylate functionalized BNQDs was synthesized with two steps fabrication approache which were contained mechanical milling and solvothermal process. It has been shown that 12 hours for mechanical milling and 24 hours for solvothermal process would be the most optimum time that produce well disperse functionalized BNQDs . The characterization results have proved that the as-prepared BNQDs have lateral size at around 5 nm with thickness in range of 4-6 layers. Also, it has been demonstrated that OH functional groups can attache into the surface of... 

    Synthesis and Investigation of Antibacterial Activity of Nanostructures Carbon Nitride g-C3N4 Photocatalyst under Visible Light

    , M.Sc. Thesis Sharif University of Technology Ahmadi, Marzie (Author) ; RoustaAzad, Reza (Supervisor) ; Vosoughi, Manouchehr (Supervisor) ; Padervand, Mohsen (Supervisor)
    Abstract
    Carbon nitride is a compound that has the proper energy gap (2.7 eV) for activities in the visible light. In this research, photocatalysts based on nanoporous Carbon nitride sheets was synthesized with three primary ingredient (urea, melamine and melamine hydrochloride) by pyrolysis method. Ag, Cu, Fe2O3 and Fe3O4 were added to the system to prevent the electron-hole recombination as well as increscent the photocatalytic activity. The chemical bonding state properties and microstructure of the synthesized photocatalysts were investigated by means of XRD, SEM, BET, FTIR, DRS and PL methods. In the first step of the research, the activity of prepared compounds was analyzed by visible light for... 

    Photocatalytic Properties of Heat-treated Carbon Nitride to Reduce Cyanide Pollutant from Aqueous Solution

    , M.Sc. Thesis Sharif University of Technology Mahtabpour, Hossein (Author) ; Sadrnezhad, Khatiboleslam (Supervisor)
    Abstract
    Cyanide ion is one of the materials used in various industries related to metallurgy, the release of which in the environment causes water, air and soil pollution. Numerous researchers have used different methods to remove this pollutant from the environment. Comparing these methods with each other, photocatalytic processes have attracted a lot of attention due to the use of sunlight as a sustainable energy source, good efficiency, low cost, etc. Therefore, in the present study, first the heat-treated graphite carbon-nitride photocatalyst was synthesized and then characterized by X-ray diffraction (XRD) tests, infrared spectroscopy (FT-IR), scattered reflectance spectroscopy (DRS),... 

    Synthesis, Characterization, and Enhanced Optical/Electronic Properties of g-C3N4 Nanosheets for Water Remediation

    , Ph.D. Dissertation Sharif University of Technology Yousefi, Mahdieh (Author) ; Moshfegh, Alireza (Supervisor) ; Asgari, Reza (Supervisor) ; Naseri, Naimeh (Co-Supervisor)
    Abstract
    A global concern has arisen owing to rapid industrial development and population growth, resulting in energy scarcity and earth pollution. In this regard, developing green and sustainable methods for producing clean energy and solving environmental pollution problems have absorbed enormous attention. Among various auspicious strategies, semiconductor photocatalysis has been widely studied in recent years owing to its capabilities to obtain hydrogen as an energy carrier, to remove organic pollutants, and to reduce CO2 emission by converting solar energy into chemical energy. Recently, a metal-free semiconductor photocatalyst based on graphitic carbon nitride, g-C3N4, has received much... 

    Synthesis and Photocatalytic Performance Study of Ag/Polydopamine Graphitic Carbon Nitride Nanocomposite

    , M.Sc. Thesis Sharif University of Technology Shahsavandi, Faezeh (Author) ; Madaah Hosseini, Hamid Reza (Supervisor)
    Abstract
    Developing an efficient visible-light-driven photocatalyst is believed to be a practical solution for clean energy and environmental remediation. The present study aimed to broaden current knowledge of the graphitic carbon nitride (g-C3N4)-based plasmonic photocatalysts by decorating polydopamine-grafted g-C3N4 (PDA/g-C3N4) with silver nanoparticles (AgNPs). The ternary nanocomposite was prepared using a facile synthesis method, while XPS and electron microscopy measurements confirmed the homogenous dispersion of AgNPs on PDA/g-C3N4. It was revealed that AgNPs successfully reduced the recombination rate of photoinduced electron-hole charge carriers. The calculated bandgap energy was... 

    Fabrication and Evaluation of Anti-Corrosion Properties of Epoxy/Modified Graphitic Carbon Nitride (g-3N4) Nanocomposite on Mild Steel

    , M.Sc. Thesis Sharif University of Technology Hassanzadeh, Abolfazl (Author) ; Ramazani Saadatabadi, Ahmad (Supervisor)
    Abstract
    In order to protect the corrosion of steel, a self-healing epoxy nanocomposite containing modified graphite carbon nitride (g-C3N4) and ZIF-67 was made along with benzotriazole (BTA) and cerium inhibitors. To increase the efficiency and also to increase the duration of use of inhibitors, it is better to load these inhibitors on containers such as MOFs. One of the useful MOFs for this purpose is ZIF-67, which has a high specific surface area that allows the transport of inhibitors with high capacity. But these containers fail after some time, so to improve the physical properties of the coating systems, g-C3N4 was also used as a mineral material, which of course was also used as a filler.... 

    Synthesis of Amine-Functionalized BN Quantum Dots for Active Targeting of SKOV3 Cells and Cell Imaging in a Microfluidics System

    , M.Sc. Thesis Sharif University of Technology Bagheri, Omid (Author) ; Simchi, Abdolreza (Supervisor) ; Mohammadi, Mohammad Reza (Supervisor)
    Abstract
    The biocompatibility and chemical stability of boron nitride nanomaterials surpass those of carbon nanomaterials. In addition, boron nitride nanomaterials share the same structure as graphene materials, making them a suitable replacement for graphene in biological applications. In this study, SKOV3 cancer cells were actively targeted using amine-functionalized boron nitride quantum dots that were covalently modified by CD133 antibody. Under the condition that they are not conjugated with antibody, these nanoparticles were also incorporated into the microfluidic device designed to image MCF7 cancer cells. These nanoparticles were produced via solvothermal synthesis in an organic solvent... 

    Nanorod carbon nitride as a carbo catalyst for selective oxidation of hydrogen sulfide to sulfur

    , Article Journal of Hazardous Materials ; Volume 364 , 2019 , Pages 218-226 ; 03043894 (ISSN) Kamali, F ; Eskandari, M. M ; Rashidi, A ; Baghalha, M ; Hassanisadi, M ; Hamzehlouyan, T ; Sharif University of Technology
    Elsevier B.V  2019
    Abstract
    Two-dimensional mesoporous carbon nitride and its highly efficient nanorod framework were prepared via hard-templating method. The obtained materials were fully characterized. The results showed that the samples structural ordering and morphology were similar to those of the parent silica templates; they had large pore volumes as well as high surface area structures. Carbon nitride carbocatalysts were used for H2S selective oxidation. The catalytic tests were carried out at 190, 210 and 230 °C in a fixed bed reactor. The obtained selectivity values for mesoporous carbon nitride rod and mesoporous carbon nitride toward elemental sulfur at 190 °C were 88.8% and 83%, respectively. Both samples... 

    Microstructure and cutting performance investigation of Ti(C, N)-based cermets containing various types of secondary carbides

    , Article International Journal of Machine Tools and Manufacture ; Volume 47, Issue 5 SPEC. ISS , 2007 , Pages 768-772 ; 08906955 (ISSN) Rahimi Dizaji, V ; Rahmani, M ; Faghihi Sani, M ; Nemati, Z ; Akbari, J ; Sharif University of Technology
    Elsevier Ltd  2007
    Abstract
    In this paper, the effects of type and amount of various secondary carbides on the microstructure and cutting performance of Ti(C0.7N0.3)-12Co system have been investigated. Nine alloys with different amounts of WC, Mo2C and Ta0.7Nb0.3C additives were studied, using scanning electron microscopy (SEM), Vickers hardness (HV), transverse rupture strength (TRS) and continuous turning tests. Alloys including Mo2C and WC presented finer carbonitride grain structure, as well as higher wear resistance resulting from their higher hardness and highly solution hardened binder phase. © 2006 Elsevier Ltd. All rights reserved  

    Growth and characterization of TixNi1-x shape memory thin films using simultaneous sputter deposition from separate elemental targets

    , Article Thin Solid Films ; Volume 491, Issue 1-2 , 2005 , Pages 190-196 ; 00406090 (ISSN) Sanjabi, S ; Sadrnezhaad, S. K ; Yates, K. A ; Barber, Z. H ; Sharif University of Technology
    2005
    Abstract
    The fabrication of TixNi1-x shape memory films using simultaneous magnetron sputtering from two separate, elemental targets was investigated. The films were deposited at room temperature and then annealed at 500 °C to achieve the shape memory effect. The influence of sputtering parameters such as power ratio to the targets (to control the composition) and Ar gas pressure (to control the film structure) were studied. It was found that the Ar gas pressure had a critical influence on the shape memory effect of the films. Characterization of the films was carried out by energy dispersive X-ray spectroscopy in a scanning electron microscope (to measure the film composition and uniformity), in... 

    Nanocarbon-based Nanocatalyst Design & Synthesis for Hydrogen Sulfide Removal from Gas Feed

    , M.Sc. Thesis Sharif University of Technology Kamali, Farnoush (Author) ; Baghalha, Morteza (Supervisor) ; Eskandari, Mohammad Mehdi (Supervisor)
    Abstract
    well known metal-free nanostructure carbon-based catalyst, mesoporous graphitic carbon nitride, with diverse morphologies were synthesized by using ethylendiamine/carbontetrachloride as a precursor, SBA-15 and SBA-15 nanorod as hard templates. We have investigated morphology effect on the catalytic performance. The catalysts were characterized by means of low angle and wide angle XRD, BET, FT-IR, CHNOS, FE-SEM analysis. Because of high surface area, pore volume and high nitrogen content, which acts as lewis basic site, for the first time, carbon nitride is chosen for selective catalytic oxidation of hydrogen sulfide to sulfure. Reaction was taken place in a fixed-bed reactor and at... 

    Photocatalytic Degradation of Organic Pollutants in the Presence of Nanocomposites Based on Graphitic Carbon Nitride under Visible Light Illumination

    , M.Sc. Thesis Sharif University of Technology Hasanvandian, Farzad (Author) ; Hamzehlouyan, Tayebeh (Supervisor) ; Rahman Setayesh, Shahrbanoo (Co-Supervisor)
    Abstract
    The susceptible light-harvesting and tremendous reduction capability along with the potentiality (photo)electrochemical merits of the thiospinels like CuCo2S4 (CCS) bring forth appreciably an advancement in efficacious photocatalytic reactions. However, scant oxidation potential originated from 3p orbitals of sulfur atoms puts a damper on their performance and is even conducive to self-oxidation. In this research, the surfactant/template free of hierarchical CCS thiospinels was synthesized using solvothermal sulfidation of the affordable glycerate-based CuCo-alkoxide and successfully was embedded with Z-scheme V2O5 deposited on wrinkled g-C3N4 lamella (VO-UCN) in the interest of developing... 

    Chromium carbonitride coating produced on DIN 1.2210 steel by thermo-reactive deposition technique: Thermodynamics, kinetics and modeling

    , Article Surface and Coatings Technology ; Volume 225 , 2013 , Pages 1-10 ; 02578972 (ISSN) Khalaj, G ; Nazari, A ; Khoie, S. M. M ; Khalaj, M. J ; Pouraliakbar, H ; Sharif University of Technology
    2013
    Abstract
    A duplex surface treatment on DIN 1.2210 steel has been developed involving nitriding and followed by chromium thermo-reactive deposition (TRD) techniques. The TRD process was performed in molten salt bath at 550, 625 and 700°C for 1-14h. The process formed a thickness up to 9.5μm of chromium carbonitride coatings on a hardened diffusion zone. Characterization of the coatings by means of scanning electron microscopy (SEM) and X-ray diffraction analysis (XRD) indicates that the compact and dense coatings mainly consist of Cr(C,N) and Cr2(C,N) phase. All the growth processes of the chromium carbonitride obtained by TRD technique followed a parabolic kinetics. Activation energy (Q) for the... 

    Mechanochemical green synthesis of exfoliated edge-functionalized boron nitride quantum dots: application to vitamin c sensing through hybridization with gold electrodes

    , Article ACS Applied Materials and Interfaces ; Volume 10, Issue 34 , 2018 , Pages 28819-28827 ; 19448244 (ISSN) Angizi, S ; Hatamie, A ; Ghanbari, H ; Simchi, A ; Sharif University of Technology
    American Chemical Society  2018
    Abstract
    Two-dimensional boron nitride quantum dots (2D BNQDs) with excellent chemical stability, high photoluminescence efficiency, and low toxicity are a new class of advanced materials for biosensing and bioimaging applications. To overcome the current challenge about the lack of facile, scalable, and reproducible synthesis approach of BNQDs, we introduce a green and facile approach based on mechanochemical exfoliation of bulk h-BN particles in ethanol. Few-layered hydroxylated-functionalized QDs with a thickness of 1-2 nm and a lateral dimension of 2-6 nm have been prepared. The synthesized nanocrystals exhibit a strong fluorescence emission at 407 and 425 nm with a quantum efficiency of ∼6.2%.... 

    Effect of severe shot peening and ultra-low temperature plasma nitriding on Ti-6Al-4V alloy

    , Article Vacuum ; Volume 150 , April , 2018 , Pages 69-78 ; 0042207X (ISSN) Unal, O ; Maleki, E ; Varol, R ; Sharif University of Technology
    Elsevier Ltd  2018
    Abstract
    In this study, the fatigue behavior of Ti-6Al-4V alloy is tend to be improved by severe plastic deformation via shot peening and plasma nitriding. Shot peening with sub-branches: Conventional shot peening (A12-14), severe shot peening (A28–30 and A34-36) and repeening (N6-8) are exposed. Besides plasma nitriding is implemented at 500 °C, 550 °C and 600 °C with the durations of 4, 8 and 16 h. Due to utilization of shot peening as prior severe plastic deformation during diffusion of nitrogen, two methods are applied in sequence. Severe shot peening forms ultra-fine crystals and oriented grains by disintegrating of α and β phases just below the surface and increases surface roughness. Plasma... 

    Surface/edge functionalized boron nitride quantum dots: Spectroscopic fingerprint of bandgap modification by chemical functionalization

    , Article Ceramics International ; Volume 46, Issue 1 , 2020 , Pages 978-985 Angizi, S ; Shayeganfar, F ; Hasanzadeh Azar, M ; Simchi, A ; Sharif University of Technology
    Elsevier Ltd  2020
    Abstract
    Promising properties of boron nitride nanomaterials such as their chemical, thermal, and mechanical stability have made them suitable materials in a various range of applications. However, their low electrical conductivity and wide bandgap, particularly in the case of boron nitride quantum dots (BNQDs), have given rise to severe limitations. Efforts on bandgap engineering through doping and surface functionalization have gained little success due to their high thermodynamic stability and inertness. Herein, we present a novel approach to functionalize BNQDs by hydroxyl, methyl, and amine functional groups aiming to adjust the electronic structure. The successful exfoliation is demonstrated by... 

    Sonophotocatalytic degradation of sulfadiazine by integration of microfibrillated carboxymethyl cellulose with Zn-Cu-Mg mixed metal hydroxide/g-C3N4 composite

    , Article Separation and Purification Technology ; Volume 245 , 2020 Gholami, P ; Khataee, A ; Vahid, B ; Karimi, A ; Golizadeh, M ; Ritala, M ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    This research aimed to prepare a recoverable sonophotocatalyst, in which microfibrillated carboxymethyl cellulose (MFC) acted as the Zn-Cu-Mg-mixed metal hydroxide/graphitic carbon nitride (MMH/g-C3N4) carrier. The characteristics of bare and composite sonophotocatalysts were analyzed by the XRD, FT-IR, BET, DRS, PL and FE-SEM equipped with the EDX mapping. The performance of prepared composites (MMH/g-C3N4@MFC) with various weight ratios of the MMH/g-C3N4 was studied for the sonophotocatalytic degradation of sulfadiazine (SDZ) as the model emerging contaminant. 93% of SDZ was degraded using the most effective catalyst (MMH/g-C3N4@MFC3) with 15% weight ratio of the MMH/g-C3N4 under the... 

    One-pot microwave synthesis of hierarchical C-doped CuO dandelions/g-C3N4 nanocomposite with enhanced photostability for photoelectrochemical water splitting

    , Article Applied Surface Science ; Volume 530 , 2020 Hosseini Hosseinabad, S. M ; Siavash Moakhar, R ; Soleimani, F ; Sadrnezhaad, S. K ; Masudy Panah, S ; Katal, R ; Seza, A ; Ghane, N ; Ramakrishna, S ; Sharif University of Technology
    Elsevier B.V  2020
    Abstract
    Cupric oxide (CuO) is a semiconductor of choice for photocathode in photoelectrochemical (PEC) applications due to its great sunlight absorption capability. However, photocorrosion is the main drawback of CuO. Herein, CuO/graphitic carbon nitride (g-C3N4) with a unique microstructure, enhanced PEC performance, and considerable photostability is synthesized under microwave irradiation. A facile, one-pot method is utilized to directly deposit the nanocomposite onto fluorine-doped tin oxide from a solution containing copper precursor and urea. Possible mechanism of CuO/g-C3N4 formation through this novel method is investigated. It is elucidated that controlled amounts of urea critically... 

    α-Helical antimicrobial peptide encapsulation and release from boron nitride nanotubes: A computational study

    , Article International Journal of Nanomedicine ; Pages 4277-4288 , Volume 16 , 2021 ; 11769114 (ISSN) Zarghami Dehaghani, M ; Yousefi, F ; Bagheri, B ; Seidi, F ; Mashhadzadeh, A. H ; Rabiee, N ; Zarrintaj, P ; Mostafavi, E ; Saeb, M. R ; Kim, Y. C ; Sharif University of Technology
    Dove Medical Press Ltd  2021
    Abstract
    Introduction: Antimicrobial peptides are potential therapeutics as anti-bacteria, anti-viruses, anti-fungi, or anticancers. However, they suffer from a short half-life and drug resistance which limit their long-term clinical usage. Methods: Herein, we captured the encapsulation of antimicrobial peptide HA-FD-13 into boron nitride nanotube (BNNT) (20,20) and its release due to subsequent insertion of BNNT (14,14) with molecular dynamics simulation. Results: The peptide-BNNT (20,20) van der Waals (vdW) interaction energy decreased to −270 kcal·mol−1 at the end of the simulation (15 ns). However, during the period of 0.2–1.8 ns, when half of the peptide was inside the nanotube, the... 

    Boron nitride nanotube as an antimicrobial peptide carrier: A theoretical insight

    , Article International Journal of Nanomedicine ; Volume 16 , 2021 , Pages 1837-1847 ; 11769114 (ISSN) Zarghami Dehaghani, M. Z ; Bagheri, B ; Yousefi, F ; Nasiriasayesh, A ; Mashhadzadeh, A. H ; Zarrintaj, P ; Rabiee, N ; Bagherzadeh, M ; Fierro, V ; Celzard, A ; Saeb, M. R ; Mostafavi, E ; Sharif University of Technology
    Dove Medical Press Ltd  2021
    Abstract
    Introduction: Nanotube-based drug delivery systems have received considerable attention because of their large internal volume to encapsulate the drug and the ability to penetrate tissues, cells, and bacteria. In this regard, understanding the interaction between the drug and the nanotube to evaluate the encapsulation behavior of the drug in the nanotube is of crucial importance. Methods: In this work, the encapsulation process of the cationic antimicrobial peptide named cRW3 in the biocompatible boron nitride nanotube (BNNT) was investigated under the Canonical ensemble (NVT) by molecular dynamics (MD) simulation. Results: The peptide was absorbed into the BNNT by van der Waals (vdW)...