scholarly journals Production, characterization of Fe3O4@CuO composite photocatalysts and determination of photocatalytic activity on Rhodamine B

2020 ◽  
Vol 1 (4) ◽  
pp. 26-29
Author(s):  
Derya TekinTekinTekinTekin

In this study, the hydrothermal method was used to synthesize the Fe3O4 particles and the Fe3O4@CuO composite photocatalyst. The XRD, SEM-EDS, UV-Vis, and VSM analyzes were used for the characterization of the synthesized particles and composites. The photocatalysts were determined to show typical Fe3O4 and CuO properties by XRD analysis which were used to determine the crystal structure of photocatalyst. The SEM analysis was used to investigate the surface morphology of photocatalysts and it was determined that the photocatalysts completed their spherical formation and showed a homogeneous distribution. In addition, the presences of Fe, Cu, and O elements were determined by EDS analysis. The band gap energies of Fe3O4 and Fe3O4@CuO with UV-Vis measurements were found to be 1.3 and 1.6 eV, respectively. The results of VSM analysis revealed that the Fe3O4 and Fe3O4@CuO photocatalysts showed approximately the superparamagnetic properties. The degradation of Rhodamine B dye on the photocatalysts was investigated in determining the photocatalytic activities of photocatalysts. The Fe3O4@CuO composite photocatalyst showed 76% of dye decomposition.

2018 ◽  
Vol 69 (10) ◽  
pp. 2662-2668
Author(s):  
S. Muthupoongodi ◽  
Liviu Mitu ◽  
T. Linda ◽  
X. Sahaya Shajan ◽  
S. Balakumar

TiO2 and V2O5 added polymer nanocomposites (NCs) were prepared by solution cast method and characterized by UV-Vis-DRS spectroscopy, powder X-ray diffraction, FTIR and SEM analysis. These characterization studies were employed to investigate the structure, optical property, phase formation and morphology of the prepared polymer NCs. The photocatalytic activities of the NCs were studied by observing the degradation of model dyes congo red (CR) and rhodamine B (RhB) under 365 nm of UV-light irradiation. In addition the recyclability and reusability of the catalyst were also examined. The results showed that nearly 95 % congo red and rhodamine B had undergone degradation in 160 and 80 mins of reaction time respectively. The catalyst shows better recyclability and can be reused for at least 6 times. In particular V2O5 added polymer NCs shows better catalytic activity towards the degradation of organic dyes. In the photodegradation process the photo-induced holes were considered to be the dominant active species. The reported catalytic system is found to be a simple, reusable and effective model for the degradation of dye polluted effluent water.


2020 ◽  
Vol 16 (4) ◽  
pp. 578-583
Author(s):  
Muhammad Asif Hussain ◽  
Adnan Maqbool ◽  
Abbas Saeed Hakeem ◽  
Fazal Ahmad Khalid ◽  
Muhammad Asif Rafiq ◽  
...  

Background: The development of new bioimplants with enhanced mechanical and biomedical properties have great impetus for researchers in the field of biomaterials. Metallic materials such as stainless steel 316L (SS316L), applied for bioimplants are compatible to the human osteoblast cells and bear good toughness. However, they suffer by corrosion and their elastic moduli are very high than the application where they need to be used. On the other hand, ceramics such as hydroxyapatite (HAP), is biocompatible as well as bioactive material and helps in bone grafting during the course of bone recovery, it has the inherent brittle nature and low fracture toughness. Therefore, to overcome these issues, a hybrid combination of HAP, SS316L and carbon nanotubes (CNTs) has been synthesized and characterized in the present investigation. Methods: CNTs were acid treated to functionalize their surface and cleaned prior their addition to the composites. The mixing of nano-hydroxyapatite (HAPn), SS316L and CNTs was carried out by nitrogen gas purging followed by the ball milling to insure the homogeneous mixing of the powders. In three compositions, monolithic HAPn, nanocomposites of CNTs reinforced HAPn, and hybrid nanocomposites of CNTs and SS316L reinforced HAPn has been fabricated by spark plasma sintering (SPS) technique. Results: SEM analysis of SPS samples showed enhanced sintering of HAP-CNT nanocomposites, which also showed significant sintering behavior when combined with SS316L. Good densification was achieved in the nanocomposites. No phase change was observed for HAP at relatively higher sintering temperatures (1100°C) of SPS and tricalcium phosphate phase was not detected by XRD analysis. This represents the characteristic advantage with enhanced sintering behavior by SPS technique. Fracture toughness was found to increase with the addition of CNTs and SS316L in HAPn, while hardness initially enhanced with the addition of nonreinforcement (CNTs) in HAPn and then decrease for HAPn-CNT-SS316L hybrid nanocomposites due to presence of SS316L. Conclusion: A homogeneous distribution of CNTs and SPS technique resulted in the improved mechanical properties for HAPn-CNT-SS316L hybrid nanocomposites than other composites and suggested their application as bioimplant materials.


2021 ◽  
Vol 10 (2) ◽  
pp. 59-63
Author(s):  
Hai Pham Viet ◽  
Anh Dao Thi Ngoc ◽  
Viet Nguyen Minh ◽  
Ha Tran Thi Viet ◽  
Dang Do Van ◽  
...  

In this study, direct Z–scheme heterostructure CoWO4/g-C3N4 was synthesized by a facile hydrothermal method. The structural, morphological properties of the prepared samples were characterised by XRD, SEM, UV–Vis and PL measurements. The as-obtained heterostructure CoWO4/g-C3N4 exhibited enhanced photocatalytic activities toward the degradation of Rhodamine B under visible light irradiation with 92% Rhodamine B removal after 80 minutes irritation, which exceeded pristine g-C3N4 and CoWO4. The enhanced photocatalytic performance ascribed to interfacial contact between g-C3N4 and CoWO4, thus further inhibiting the recombination of photogenerated electron/hole pairs. It is anticipated that the construction of Z–scheme heterostructure CoWO4/g-C3N4 is an effective strategy to develop high-performance photocatalysts for the degradation of organic pollutants in water.


2014 ◽  
Vol 1036 ◽  
pp. 164-167 ◽  
Author(s):  
Grzegorz Moskal ◽  
Lucjan Swadźba ◽  
Wacław Supernak ◽  
Marta Mikuśkiewicz ◽  
Adrian Mościcki ◽  
...  

Characterization of microstructure of silicide coatings obtained during diffusion process of pack cementation type was showed in this article. The basic materials were pure Mo sheet and TZM molybdenum alloys as well. The coatings were deposited in out of pack process with three different times of exposure. The temperature of deposition process was constant. In first step the phases compositions of coatings was described by XRD analysis. In each cases the MoSi2 phase was obtained on top surface of the coatings. The morphology of the coatings was very similar as well. All types of coatings were characterized by network of cracks on top surface of the coatings. There was no influence of depositions time on phases constituent and coatings topography. LM and SEM analysis revealed that internal coatings morphology was very similar in all cases. Basic differences was related to the thickness of coatings. All coatings were good quality without deep cracks. Microstructure was a columnar-like type without pores and voids.


2013 ◽  
Vol 587 ◽  
pp. 239-244 ◽  
Author(s):  
Kunjalukkal Padmanabhan Sanosh ◽  
Francesca Gervaso ◽  
Alessandro Sannino ◽  
Antonio Licciulli

In the present work Collagen/Hydroxyapatite microsphere (Col/mHA) scaffold with a multiscale porosity was prepared. Col/mHA composite scaffold was prepared by freeze-drying/dehydrothermal crosslinking method. The HA microspheres (mHA) were obtained by spray drying of nanohydroxyapatite slurry prepared by precipitation technique. XRD analysis revealed that the microspheres were composed only of pure HA phase and EDS analysis revealed that Ca/P ratio was 1.69. The obtained microspheres had an average diameter 6 microns, specific surface area of 40 m2/g by BET analysis and BJH analysis shows meso porous structure having an average pore diameter 16nm. SEM analysis shows that the obtained Col/mHA scaffold had a macro porosity ranging from micron to 200 microns with meso porous mHA embedded in the collagen matrix.


Jurnal MIPA ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 23
Author(s):  
Engellita Maneking ◽  
Hanny Frans Sangian ◽  
Seni Herlina Juita Tongkukut

Penelitian ini bertujuan untuk membuat dan mengkarakterisasi bioplastik yang memanfaatkan biomassa singkong. Pembuatan bioplastik dilakukan dengan dua variasi campuran yaitu pati singkong sebagai bahan dasar, gliserol + air sebagai plasticizer, asam asetat (cuka) sebagai katalis dan variasi kedua dengan kombinasi yang sama dengan penambahan alkohol sebagai pembanding. Karakterisasi bioplastik meliputi pengamatan permukaan menggunakan SEM; kristalinitas menggunakan XRD; penentuan gugus fungsi menggunakan FTIR; serta menganalisis sifat termal menggunakan TGA dan DSC. Hasil karakterisasi menunjukkan bahwa bioplastik dengan kombinasi pati singkong+ gliserol + air + asam asetat (cuka) + alkohol mempunyai tingkat degradasi yang tinggi. Hal ini sesuai dengan analisis XRD dimana kombinasi ini memiliki nilai kristalinitas rendah. Hasil spektra IR menunjukkan adanya gugus C-H Alkana, C=O ester, dan C-H Alkena. Sementara hasil SEM memperlihatkan permukaan yang rata dan hasil analisis TGA/DSC yang memperlihatkan pengurangan massa sebesar 2,3234 mgThis study aims to create and characterize bioplastics that utilize cassava biomass. The making of bioplastics is carried out for two variations of mixture, namely cassava starch as the material-based, glycerol + water as plasticizer, acetic acid (vinegar) as a catalyst and the second variation with the same combination with the addition of alcohol as a comparison. Characterization of bioplastics includes surface observations using SEM; crystallinity using XRD; determination of functional groups using FTIR; and analyzing of thermal properties using TGA and DSC. The characterization results show that bioplastics with a combination of cassava starch + glycerol + water + acetic acid (vinegar) + alcohol have a high degree of degradation. This is in accordance with the XRD analysis where this combination has a low crystallinity value. IR spectra showed that the presence of C-H Alkana groups, C = O esters, and C-H alkenes. While the SEM results showed a flat surface and the results of the TGA / DSC analysis which showed a mass reduction of 2.3234 mg.This study aims to create and characterize bioplastics that utilize cassava biomass. The making of bioplastics is carried out for two variations of mixture, namely cassava starch as the material-based, glycerol + water as plasticizer, acetic acid (vinegar) as a catalyst and the second variation with the same combination with the addition of alcohol as a comparison. Characterization of bioplastics includes surface observations using SEM; crystallinity using XRD; determination of functional groups using FTIR; and analyzing of thermal properties using TGA and DSC. The characterization results show that bioplastics with a combination of cassava starch + glycerol + water + acetic acid (vinegar) + alcohol have a high degree of degradation. This is in accordance with the XRD analysis where this combination has a low crystallinity value. IR spectra showed that the presence of C-H Alkana groups, C = O esters, and C-H alkenes. While the SEM results showed a flat surface and the results of the TGA / DSC analysis which showed a mass reduction of 2.3234 mg.


2018 ◽  
Vol 72 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Vladan Kasic ◽  
Slavica Mihajlovic ◽  
Dragana Zivotic ◽  
Vladimir Simic ◽  
Jovica Stojanovic ◽  
...  

This study presents investigations of zeolitic tuff samples from the ?Igros- -Vidojevici? deposit. The aim of the research was to determine the quality of samples taken from all deposit parts. Thus, samples were taken from the footwall (?Zeolit 1?), and four samples from the central deposit part (?Zeolit 2?, ?Zeolit 3?, ?Zeolit 4? and ?Zeolit 5?). Characterization of the samples included chemical analysis, determination of the adsorption coefficient for methylene blue dye and cation-exchange capacity (CEC), X-ray powder diffraction analysis (XRPD), differential thermal and thermogravimetric analysis (DTA and TGA), and Fourier transform Infrared spectroscopic analysis (FTIR). Results have shown that the footwall consists mostly of clays, whereas zeolite minerals dominate in the rest of the deposit. XRD analysis of the ?Zeolit 1? sample confirmed presence of smectite and kaolinite clays, while zeolite of analcime type and quartz are present as smaller fractions. Chemical composition analysis and determination of heavy metal contents showed a significant amount (7.58%) of Fe2O3 in this sample. Therefore, further research can be pursued to find a method for removal of magnetic impurities in this deposit portion in order to utilize the clay fraction. On the other hand, according to XRD, FTIR, DTA/TGA and SEM/EDS analyses, samples which belong to the central deposit part (?Zeolit 2?5?) consist of clinoptilolite zeolite type, while clays are present in less than 10%. Thus, clays (smectites and kaolinite) accompanied with analcime and quartz are the most abundant footwall minerals while central deposit parts contain predominantly clinoptilolite accompanied with small amounts of clays. Mineragenetically, zeolites are most abundant in the ?Zeolit 2? and ?Zeolit 3? samples. The smallest value of CEC was determined for the ?Zeolit 1? sample (46.98 mmol/100g). According to CEC values determined for ?Zeolit 2? and ?Zeolit 3? (141.99 and 121.01 mmol/100 g, respectively) these samples are of the best quality, and could be utilized as adsorbents of inorganic pollutants from contaminated waters. Moreover, they could be potentially used for removal of mycotoxins from cattle feed. ?Zeolit 4? and ?Zeolit 5? samples have shown slightly lower CEC values (89.48 and 83.75 mmol/100 g, respectively), which implies lower quality, and, therefore, could be used for soil quality improvement. Finally, determination of the external CEC has revealed a significant difference between ?Zeolit 1? and ?Zeolit 5? samples (17.9 and 5.31 mmol/100 g, respectively).


Author(s):  
Priscila Richa ◽  
Roberto Costa Lima ◽  
Ana Paula Santiago de Falco ◽  
Ana Paula da Silva ◽  
Elvia Leal ◽  
...  

Radar-absorbing materials (RAMs) have been used in military applications for several decades to reduce radar detection of vessels and aircrafts. In the present work, the performance of Ni0.35Zn0.35Cu0.3Fe2O4 ferrite as a RAM is investigated. The ferrite was firstly synthesized by combustion reaction and then calcinated at 1200 °C for 1 h. Composites were prepared with 80:20, 70:30 and 60:40 concentrations in weight of ferrite:polychloroprene. The X-ray diffraction (XRD) analysis showed a single phase ferrite formation and the scanning electron microscopy (SEM) analysis of the composites showed a good dispersion of the ferrite in the polychloroprene matrix. The electromagnetic (EM) characterization of the composites revealed that the EM attenuation is mainly attributed to magnetic losses observed in the material. The 80:20 composite achieved the best performance and presented a reflectivity of -26.7 dB at 10.2 GHz.


2018 ◽  
Vol 3 (2) ◽  
Author(s):  
Maria Ulfah ◽  
Sri Aprilia ◽  
Fauzi M. Djuned

<p>Utilization of wood powder is one of the alternative in waste wood prevention which has not been optimally utilized. Utilization of bionanofiller based on wood waste such as wood powder can also reduce dependence on raw materials such as silica, clay, bentonite, zeolite which diminished its existence. The sample used in this study is Meranti wood powder which is then prepared and characterized. The characterization of bionanofiller waste of Meranti wood powder is done by analyzing particle density, XRD, SEM, and FTIR. Particle density analysis showed Meranti wood powder having density of 0,044 gr/cm . XRD analysis shows that the maximum peak at an angle of 2θ = 22,2o 3 indicates the presence of carbon phase. The results of SEM analysis of Meranti wood powder are suitable for use as fillers because they are 1 μm in size. The result of functional group analysis shows the presence of functional groups -OH, -CH3, -CH2, C = C, C-H and C-O.</p>


2021 ◽  
Vol 57 (4) ◽  
pp. 225-235
Author(s):  
Suripto D. Yuwono ◽  
Endah Wahyuningsih ◽  
Noviany ◽  
Agung A. Kiswandono ◽  
Wasinton Simanjuntak ◽  
...  

In this study, carboxymethyl cellulose (CMC) was synthesized from the cellulose of cassava peel using alkalization and etherification reaction, and it was subsequently characterized with various techniques. Microcellulose was obtained by hydrolyzing a;-cellulose from cassava peel using H2SO4 with concentrations of 45%, 47%, and 49%. The experimental results indicate that the varying concentrations of acid affect the particle size of the cellulose, with 49% H2SO4 solution producing a cellulose with particle size of around 0.45-2.42 �m and relative percentage of 11.3% according to PSA analysis. Other analyses conducted included determination of substitution degrees, DTG/DTA/TGA, FTIR, SEM, and XRD. The value of the substitution degree was determined at 0.27. TGA decomposition thermograms at a temperature of 150oC-320oC of 19.60 % indicate CMC compounds. DTA thermograms show that these CMC compounds have endothermic properties at 140oC and exothermic properties at 260oC. FTIR spectra show the presence of absorption band at wave number 1605 cm-1, which is a characteristic absorption of carbonyl group bound to cellulose. The results of SEM analysis indicate that the CMC has a tenuous surface morphology, and the XRD diffractograms are marked by the presence of weak peak at 2e = 20o, implying the existence of CMC as mostly amorphous.


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