scholarly journals Effect of Activating Agent on the Properties of TiO2/Activated Carbon Heterostructures for Solar Photocatalytic Degradation of Acetaminophen

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 378 ◽  
Author(s):  
Manuel Peñas-Garzón ◽  
Almudena Gómez-Avilés ◽  
Jorge Bedia ◽  
Juan Rodriguez ◽  
Carolina Belver

Several activated carbons (ACs) were prepared by chemical activation of lignin with different activating agents (FeCl3, ZnCl2, H3PO4 and KOH) and used for synthesizing TiO2/activated carbon heterostructures. These heterostructures were obtained by the combination of the activated carbons with a titania precursor using a solvothermal treatment. The synthesized materials were fully characterized (Wavelength-dispersive X-ray fluorescence (WDXRF), X-ray diffraction (XRD), Scanning electron microscopy (SEM), N2 adsorption-desorption, Fourier transform infrared (FTIR) and UV-visible diffuse reflectance spectra (UV-Vis DRS) and further used in the photodegradation of a target pharmaceutical compound (acetaminophen). All heterostructures were composed of anatase phase regardless of the activated carbon used, while the porous texture and surface chemistry depended on the chemical compound used to activate the lignin. Among all heterostructures studied, that obtained by FeCl3-activation yielded complete conversion of acetaminophen after 6 h of reaction under solar-simulated irradiation, also showing high conversion after successive cycles. Although the reaction rate was lower than the observed with bare TiO2, the heterostructure showed higher settling velocity, thus being considerably easier to recover from the reaction medium.

2021 ◽  
Vol 1162 ◽  
pp. 65-73
Author(s):  
Rakhmawati Farma ◽  
Ona Lestari ◽  
Erman Taer ◽  
Apriwandi ◽  
Minarni ◽  
...  

Heavy metal such as Cu, Fe, and Zn are the most serious contributers to environmental problems. The removal of heavy metal from the environment is the research interest nowdays. The adsorption of Cu, Fe and Zn from wastewater was investigated with various activated carbons as adsorbents. The activated carbons were produced from oil palm leaves by using multi-activation methods. The H3PO4, NaOH, ZnCl2 and KOH were chosen as chemical activating agents. Batch adsorption experiment was used to test the ability of activated carbon to remove Cu, Fe, and Zn from wastewater. The surface characteristics of activated carbon were evaluated using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), Fourier transform infrared spectroscopy (FTIR), and nitrogen adsorption-desorption isotherms. The Activated carbons were able to purify wastewater with a maximum turbidity level of 2.83 NTU. The AC-H3PO4 activated carbon showed the highest absorbability of Cu metal as 91.540%, while the highest absorbabilities of Zn and Fe metals were indicated by AC-KOH activated carbon of 22.853% and 82.244% absorption respectively. Therefore, these results enable the oil palm leaves to become a high potential for activated carbon as removal the heavy metals.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
N. Mojoudi ◽  
N. Mirghaffari ◽  
M. Soleimani ◽  
H. Shariatmadari ◽  
C. Belver ◽  
...  

AbstractThe purpose of this study was the preparation, characterization and application of high-performance activated carbons (ACs) derived from oily sludge through chemical activation by KOH. The produced ACs were characterized using iodine number, N2 adsorption-desorption, Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The activated carbon prepared under optimum conditions showed a predominantly microporous structure with a BET surface area of 2263 m2 g−1, a total pore volume of 1.37 cm3 g−1 and a micro pore volume of 1.004 cm3 g−1. The kinetics and equilibrium adsorption data of phenol fitted well to the pseudo second order model (R2 = 0.99) and Freundlich isotherm (R2 = 0.99), respectively. The maximum adsorption capacity based on the Langmuir model (434 mg g−1) with a relatively fast adsorption rate (equilibrium time of 30 min) was achieved under an optimum pH value of 6.0. Thermodynamic parameters were negative and showed that adsorption of phenol onto the activated carbon was feasible, spontaneous and exothermic. Desorption of phenol from the adsorbent using 0.1 M NaOH was about 87.8% in the first adsorption/desorption cycle and did not decrease significantly after three cycles. Overall, the synthesized activated carbon from oily sludge could be a promising adsorbent for the removal of phenol from polluted water.


2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Nurgul Ozbay ◽  
Adife Seyda Yargic

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.


Abstract: The photocatalytic composite Fe doped AC/TiO2 has been prepared by sol-gel method. The prepared Fe doped AC/TiO2 composite were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD).The SEM analysis showed that Fe and TiO2 were attached to the Activated Carbon surfaces. The X-Ray Diffraction data showed that Fe doped AC/TiO2 composite mostly contained anatase phase.


2021 ◽  
Vol 2049 (1) ◽  
pp. 012067
Author(s):  
Rakhmawati Farma ◽  
Ramadani Putri Anakis ◽  
Irma Apriyani

Abstract Biomass converted into activated carbon (AC) by using physical activation method can form micro-meso pore structure and maintain the interconnected natural pore network of biomass. AC is prepared from the biomass of Parsea Americana seeds (PAS) through a process of pre-carbonization, chemical activation, carbonization and physical activation which is activated at temperatures of 700°C, 800°C, and 900°C. Characterization of physical properties of AC electrodes consisted of X-ray diffraction, Scanning Electron Microscope-Energy Dispersive X-ray and characterization of electrochemical properties of supercapacitor cells using Cyclic Voltametry. The results showed that the microstructure of the AC electrode has a semicrystalline structure characterized by the presence of two sloping peaks at an angle of 2θ around 24° and 44° which corresponded to the hkl (002) and (100) planes, where the lowest Lc value was produced by the PAS-900 sample. The PAS-900 sample had aggregates or lumps with smaller size in small amounts in the presence of micro-mesopores and had the highest carbon content of 94.50% with the highest capacitance value of 203.12 F/g. The temperature of 900°C is the best activation temperature in the process of manufacture AC electrodes from Parsea Americana seeds biomass for supercapacitor cell applications.


2018 ◽  
Vol 8 (2) ◽  
pp. 115
Author(s):  
Andi Ikhtiar Bakti ◽  
Paulus Lobo Gareso ◽  
Nurlaela Rauf

Activated carbon is produced from the coconut shell through physical and chemical activation. The pyrolysis method was employed in this research for physical activation at an optimum temperature of 600oC and 1,000oC, for chemical activation immersed using 10% Na2CO3 activating agent. This research has produced two samples, namely the physical activation of 1,000oC and the physics-chemical activation of Na2CO3. The X-Ray Diffraction (X-RD) spectrum of activated carbon in the samples 1,000oC and Na2CO3 contained silicate minerals, iron ore and quartz, respectively, and it showed the formation of carbon and graphite structures in the hkl (002) and (100) planes. Through Scherrer’s method, the average size of the Na2CO3 crystals sample is 15.03 nm and the sample crystal sample of 1,000oC is 54.53 nm; the size of the Nano-scale crystals was formed when the temperature increases ≥ 600° C. The X-RD resulted the percentage of elemental content carbon phase volume fraction (Fv) and impurity (I) in the 1,000oC sample of 75.61%, 24.39% and the Na2CO3 sample of 77.87%, 22.13% . These results indicate that the carbon content in chemical activation is much better than the physics activation. SEM results with magnification of 5,000x, it is very clear the porosity formed of the 10 μm picture size are 0.8 μm in Na2CO3 sample and 1.00 μm in 1,000oC sample.


2019 ◽  
Vol 1 (1) ◽  
pp. 54-60
Author(s):  
Awitdrus Awitdrus

Activated carbon was prepared from Terminalia catappa shells using microwave asissted KOH activation. The ratio of mass percentages of Terminalia catappa and KOH were 4:1, 4:2, and 4:3. Terminalia catappa based activated carbon was prepared by KOH activation at the room temperature for 24 hours and followed by microwave irradiation at the out put power of 630 Watt for 20 minutes. The physical properties of activated carbon i.e. surface morphology, micro structure, and BET surface area were characterized by electron scanning microscope, X-ray diffraction and N2 adsorption-desorption isotherm at 77K, respectively. The highest BET surface area was 312 m2/g with adsorption of activated carbon towards methylene blue by 84.4 mg/g. The BET surface area was directly correlated with the stack height (Lc) of the activated carbon.


2014 ◽  
Vol 8 (4) ◽  
pp. 195-202 ◽  
Author(s):  
Marija Milanovic ◽  
Ljubica Nikolic

Pure and lanthanum doped titania nanopowders were synthesized through a room temperature sol-gel method using a template of polyethylene glycol (PEG). The progress of the synthesis in terms of phase formation and size of nanoparticles was monitored by X-ray diffraction, FTIR spectroscopy and SEM analysis. After calcination at 450?C in air, the results have shown the presence of small particles crystallized predominantly in the form of anatase phase, with significant agglomeration. Nitrogen adsorption-desorption measurements confirmed that all prepared powders are mesoporous with an average pore diameter in range 3.1-3.8 nm. The addition of lanthanum ions leads to the nanopowders with the highest specific surface (BET) area (203m2/g). The obtained powders were compared to TiO2 prepared without a template.


2021 ◽  
pp. 73-88
Author(s):  
Hayet Tizi ◽  
Tarek Berrama ◽  
Djamila Hamane ◽  
Fatiha Ferrag-Siagh ◽  
Zoubida Bendjama

This work aims to evaluate the adsorption efficiency of p-nitroaniline (PNA) onto apricot stones activated carbon (ASAC) mixed with treated extract of amorphous SiO2 (TEAS), prepared from Algerian diatomite (AD). The best removal percentage (85%) is obtained for a ratio ASAC/TEAS (1/1). Adsorbent characteristics are investigated by the Brunauer-Emmett-Teller (BET), the scanning electron microscope (SEM), infrared spectroscopy (IR), X-ray fluorescence (XRF) and X-ray diffraction (XRD). The impregnation of TEAS and ASAC produces good adsorbent properties towards PNA especially in the ratio (1/1) and an increase in the specific surface. The isotherm data are well fitted by the Langmuir and Freundlich models. The maximum PNA uptake obtained is 94.34 mg g-1. The performances of ASAC/TEAS for the PNA adsorption were compared with some adsorbents previously studied for the same purpose, and results show that the composite in the present work exhibit better performances. The adsorption behavior of the concerned material is explained on the basis of its chemical nature and porous texture.


2021 ◽  
Vol 2129 (1) ◽  
pp. 012009
Author(s):  
R Nedjai ◽  
N A Kabbashi ◽  
M Z Alam ◽  
M F R Al-Khatib

Abstract Chemical agents have a good influence on the formation of activated carbons, surface characteristic, and its adsorption properties. In this study, the effect of activating agents (ZnCl2, KOH, and H3PO4) on baobab fruit shell (BFS) were evaluated. The characteristics of the baobab fruit shell based activated carbon (BF-ACs) were evaluated through the yield and iodine number. BF-ACs were also characterized by Scanning Electron Microscope (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Diffraction (XRD), and nitrogen (N2) adsorption. SEM analysis illustrates those porous structures formed on the surface of BF-ACs were with different sizes. The XRD analysis show that the main structures of BF-ACs are amorphous. FT-IR data demonstrates the presence of different surface groups on the produced BF-ACs. Among activating agent, the KOH was observed to the most appropriate for the production of activated carbon with a large surface area (1029.44 m2/g) from baobab fruit shell.


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