scholarly journals From Adsorbent to Photocatalyst: The Sensitization Effect of SnO2 Surface towards Dye Photodecomposition

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7123
Author(s):  
Kinga Michalec ◽  
Anna Kusior
Keyword(s):  
Structural Changes ◽  
Photocatalytic Performance ◽  
Organic Dyes ◽  
Indigo Carmine ◽  
Dye Adsorption ◽  
Chemical Conversion ◽  
Photocatalytic Properties ◽  
Hydrodynamic Diameter ◽  
Micro Structure ◽  
Adsorption Desorption

Semiconductor photocatalysis is considered one of the most promising technologies for water purification from toxic organic dyes. However, to reliably evaluate the possibility of using a given material as a photocatalyst, it is crucial to investigate not only the photocatalytic activity but also its affinity towards various dyes and reusability. In this work, we studied the adsorptive/photocatalytic properties of hollow-spherical raspberry-like SnO2 and its SnO2/SnS2 heterostructures that were obtained via a chemical conversion method using three different concentrations of a sulfide precursor (thioacetamide). The adsorptive/photocatalytic properties of the samples towards cationic rhodamine B (RhB) and anionic indigo carmine (IC) were analyzed using uncommon wall zeta potential measurements, hydrodynamic diameter studies, and adsorption/photodecomposition tests. Moreover, after conducting cyclic experiments, we investigated the (micro)structural changes of the reused photocatalysts by scanning electron microscopy and Fourier-transform infrared spectroscopy. The obtained results revealed that the sensitization of SnO2 resulted not only in the significantly enhanced photocatalytic performance of the heterostructures, but also completely changed their affinity towards dyes. Furthermore, despite the seemingly best photocatalytic performance, the sample with the highest SnS2 content was unstable due to its (micro)structure. This work demonstrates that dye adsorption/desorption processes may overlap the results of cyclic photodecomposition kinetics.

scholarly journals Chitosan/Zeolite Composite Aerogels for a Fast and Effective Removal of Both Anionic and Cationic Dyes from Water

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1691
Author(s):  
Angela Marotta ◽  
Enrica Luzzi ◽  
Martina Salzano de Luna ◽  
Paolo Aprea ◽  
Veronica Ambrogi ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Broad Spectrum ◽  
Organic Dyes ◽  
Indigo Carmine ◽  
Zeolite 13X ◽  
Industrial Sectors ◽  
Effective Removal ◽  
Composite Aerogels ◽  
Zeolite Composite ◽  
Adsorption Desorption

Organic dyes are extensively used in many industrial sectors, and their uncontrolled disposal into wastewaters raises serious concerns for environmental and human health. Due to the large variety of such pollutants, an effective remediation strategy should be characterized by a broad-spectrum efficacy. A promising strategy is represented by the combination of different adsorbent materials with complementary functionalities to develop composite materials that are expected to remove different contaminants. In the present work, a broad-spectrum adsorbent was developed by embedding zeolite 13X powder (ZX) in a chitosan (CS) aerogel (1:1 by weight). The CS–ZX composite adsorbent removes both anionic (indigo carmine, IC) and cationic (methylene blue, MB) dyes effectively, with a maximum uptake capacity of 221 mg/g and 108 mg/g, respectively. In addition, the adsorption kinetics are rather fast, with equilibrium conditions attained in less than 2 h. The composite exhibits good mechanical properties in both dry and wet state, which enables its handling for reusability purposes. In this regard, preliminary tests show that the full restoration of the IC removal ability over three adsorption–desorption cycles is achieved using a 0.1 M NaOH aqueous solution, while a 1 M NaCl aqueous solution allows one to preserve >60% of the MB removal ability.

scholarly journals Enhanced adsorptive removal of Indigo carmine dye performance by functionalized carbon nanotubes based adsorbents from aqueous solution: equilibrium, kinetic, and DFT study

2019 ◽  
Vol 9 (4) ◽  
pp. 323-334 ◽  
Author(s):  
Zeinab Hoseini Dastgerdi ◽  
Seyyed Salar Meshkat ◽  
Mehdi D. Esrafili
Keyword(s):  
Density Functional ◽  
Indigo Carmine ◽  
Dye Adsorption ◽  
Chemical Vapor ◽  
Density Functional Theory Calculations ◽  
Nitrogen Adsorption ◽  
Adsorptive Removal ◽  
Langmuir Isotherm Model ◽  
Pseudo Second Order ◽  
Adsorption Desorption

AbstractThe present work considers an adsorptive removal of Indigo carmine (IC) dye onto nanotube carbon (CNTs). The pure CNTs were prepared via chemical vapor deposition (CVD) method utilizing methane gas as a carbon source at 1000 °C in a quartz tube. The morphology and surface chemical structure of the adsorbents were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), nitrogen adsorption/desorption technique, and thermal gravity analysis (TGA). The parameters of the IC dye adsorption, such as initial concentration, contact time, pH, and mass-loaded adsorbent, were evaluated. The kinetic study confirmed that a pseudo-second-order model was best fitted to the adsorption data. The removal efficiency of adsorption onto pure and COOH-functionalized CNTs was 84% and 98.7% at 15 min, respectively. The equilibrium results were fitted well to the Langmuir isotherm model. The adsorption capacity of the CNT and COOH–CNT was 88.5 and 136 mg/g, respectively. The reusability of the adsorbents was studied, and after eight cycles, the efficiency decreased to 70%. Moreover, the density functional theory calculations confirmed that the functionalization of CNTs with COOH groups improves the adsorption properties of IC due to the formation of hydrogen-bonding interactions.

Photocatalytic Degradation of Indigo Carmine Dye Using Hydrothermally Synthesized Anatase TiO2 Nanotubes under Ultraviolet Light Emitting Diode Irradiation

2016 ◽  
Vol 855 ◽  
pp. 45-57 ◽  
Author(s):  
Kalithasan Natarajan ◽  
Rukshana I. Kureshy ◽  
Hari C. Bajaj ◽  
Rajesh J. Tayade
Keyword(s):  
Photocatalytic Degradation ◽  
Band Gap ◽  
Organic Dyes ◽  
Light Emitting Diode ◽  
Indigo Carmine ◽  
Order Kinetic ◽  
Light Emitting ◽  
Order Kinetic Model ◽  
Different Temperatures ◽  
Adsorption Desorption

Anatase TiO2 nanotubes (ATNT) was synthesised by hydrothermal method using anatase TiO2 nanoparticles (AT) as precursor and calcined at two different temperatures (250 & 450 °C) for 2 h. The AT and synthesized ATNT photocatalysts were characterized by X-ray diffraction, transmission electron microscopy, N2 adsorption-desorption measurements, UV-vis diffuse reflectance and Fourier Transform Infra-red spectroscopy techniques for their structural, textural and electronic properties. The photocatalytic degradation of Indigo carmine (IC) dye aqueous solution has carried out using ATNT-250 and ATNT-450 photocatalysts under UVLED irradiation. The kinetic analysis has also revealed that the degradation of IC dye solution follows first order kinetic model. The overall study demonstrates the appropriate band gap of the photocatalysts used and the suitable irradiation source which could accelerate the rate of photocatalytic degradation. The band gap of the synthesised ATNT is not much affected due to the change in morphology from nanoparticle to nanotube. The results demonstrated that the irradiation of UV-LED could be utilised for the degradation of organic dyes

An Effect of pH on Radiation Assisted Modification of Oxygen-Rich Activated Carbon by Urea

2021 ◽  
Vol 904 ◽  
pp. 407-412
Author(s):  
Threeraphat Chutimasakul ◽  
Tinutda Phonlam ◽  
Varistha Chobpattana ◽  
Pattra Lertsarawut ◽  
Wilasinee Kingkam ◽  
...  
Keyword(s):  
Gamma Irradiation ◽  
Gas Adsorption ◽  
Activated Carbons ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Urea Solution ◽  
Activation Process ◽  
X Ray Diffraction ◽  
Green Technique ◽  
Adsorption Desorption

Activated carbons (ACs) are a versatile group of adsorbents for water pollution control, especially organic dyes. Harsh chemicals and high temperatures are required for the activation process of ACs, which becomes a significant concern due to their toxicity and harmful effects on human health and the environment. Gamma irradiation, an alternative green technique, is a promising strategy for pretreatment and escalates the nitrogen or oxygen functional group of ACs. The current study provides the modification of ACs by the gamma irradiation in the various pH (5-11) of urea solution. The modified ACs were characterized by scanning electron microscopy (SEM), nitrogen gas adsorption-desorption analysts (BET), temperature program desorption (TPD), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, and X-ray diffraction spectroscopy (XRD). The point of zero charges and dye adsorption capacities were determined. This finding demonstrates that the ACs can be modified by gamma irradiation at 25 kGy in the urea solution media. The degree of graphitization enhanced significantly at pH 11(AC-pH11). The oxygen-rich functional groups created by radiation assists could enhance the electrostatic attraction between acid gases or cationic dyes. AC-pH11 also was able to adsorb methylene blue (160.73 ± 1.70 mg/g) greater than methyl orange (127.57 ± 2.22 mg/g).

In2O3 cubes: synthesis, characterization and photocatalytic properties

RSC Advances ◽  
2014 ◽  
Vol 4 (59) ◽  
pp. 31353-31361 ◽  
Author(s):  
Sheng-qi Guo ◽  
Xiao Zhang ◽  
Zhen-wei Hao ◽  
Guan-dao Gao ◽  
Guang Li ◽  
...  
Keyword(s):  
Photocatalytic Performance ◽  
Organic Dyes ◽  
Photocatalytic Properties

Two-step prepare of In2O3 cubes, which have excellent photocatalytic performance for degeneration of organic dyes.

Parameters Affecting Dye Adsorption - Using Graphene Coated Sand (GSC)

2018 ◽  
Vol 4 (02) ◽  
Author(s):  
Seroor Atalah Khaleefa Alia ◽  
Dr. Mohammed Ibrahimb ◽  
Hussein Ali Hussein
Keyword(s):  
Heavy Metals ◽  
Contact Time ◽  
Organic Dyes ◽  
Low Cost ◽  
Dye Adsorption ◽  
Contaminated Water ◽  
Maximum Adsorption Capacity ◽  
Engineering Designs ◽  
Heavy Metals Ions ◽  
Coated Sand

Adsorption is most commonly applied process for the removal of pollutants such as dyes and heavy metals ions from wastewater. The present work talks about preparing graphenic material attached sand grains called graphene sand composite (GSC) by using ordinary sugar as a carbon source. Physical morphology and chemical composition of GSC was examined by using (FTIR, SEM, EDAX and XRD). Efficiency of GSC in the adsorption of organic dyes from water was investigated using reactive green dye with different parameters such as (ph, temperature, contact time and dose). Adsorption isotherm was also studied and the results showed that the maximum adsorption capacity of dye is 28.98 mg/g. This fast, low-cost process can be used to manufacture commercial filters to treat contaminated water using appropriate engineering designs.

3D/2D Bi2S3/SnS2 Heterostructures: Superior Charge Separation and Enhanced Solar Light Driven Photocatalytic Performance

CrystEngComm ◽  
2021 ◽  
Author(s):  
Sumana Paul ◽  
Dulal Barman ◽  
Chandra Chowdhury ◽  
Pravat Kumar Giri ◽  
Subodh Kumar De
Keyword(s):  
Charge Separation ◽  
Photocatalytic Performance ◽  
Organic Dyes ◽  
Solar Light ◽  
Toxic Ions

In promoting the application of green and sustainable solution towards the photodegradation of organic dyes and toxic ions, it is urgent to fabricate semiconductor based effective and stable photocatalysts. Constructing...

scholarly journals Pore Modification and Phosphorus Doping Effect on Phosphoric Acid-Activated Fe-N-C for Alkaline Oxygen Reduction Reaction

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1519
Author(s):  
Jong Gyeong Kim ◽  
Sunghoon Han ◽  
Chanho Pak
Keyword(s):  
Phosphoric Acid ◽  
Photoelectron Spectroscopy ◽  
Structural Changes ◽  
Electronic States ◽  
Nitrogen Adsorption ◽  
Reduction Reaction ◽  
Phosphorus Doping ◽  
X Ray ◽  
Precious Metal Catalysts ◽  
Adsorption Desorption

The price and scarcity of platinum has driven up the demand for non-precious metal catalysts such as Fe-N-C. In this study, the effects of phosphoric acid (PA) activation and phosphorus doping were investigated using Fe-N-C catalysts prepared using SBA-15 as a sacrificial template. The physical and structural changes caused by the addition of PA were analyzed by nitrogen adsorption/desorption and X-ray diffraction. Analysis of the electronic states of Fe, N, and P were conducted by X-ray photoelectron spectroscopy. The amount and size of micropores varied depending on the PA content, with changes in pore structure observed using 0.066 g of PA. The electronic states of Fe and N did not change significantly after treatment with PA, and P was mainly found in states bonded to oxygen or carbon. When 0.135 g of PA was introduced per 1 g of silica, a catalytic activity which was increased slightly by 10 mV at −3 mA/cm2 was observed. A change in Fe-N-C stability was also observed through the introduction of PA.

scholarly journals Ultrasound-irradiated synthesis of 3-mercaptopropyl trimethoxysilane-modified hydroxyapatite derived from fish-scale residues followed by ultrasound-assisted organic dyes removal

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Phitchan Sricharoen ◽  
Supalak Kongsri ◽  
Chunyapuk Kukusamude ◽  
Yonrapach Areerob ◽  
Prawit Nuengmatcha ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Textile Industry ◽  
Organic Dyes ◽  
Dye Adsorption ◽  
Ultrasound Irradiation ◽  
Coefficient Of Determination ◽  
Fish Scale ◽  
Transmission Electron ◽  
Endothermic Process ◽  
Langmuir Isotherm Model

AbstractWe report a novel method for the synthesis of 3-mercaptopropyl trimethoxysilane-modified hydroxyapatite (FHAP-SH) derived from fish-scale residues by using ultrasound irradiation. Scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy were used for the FHAP-SH characterization. Then, the organic dye adsorption on the FHAP-SH was monitored through an ultrasound process. After the dye removal optimization, significant improvements were observed in the maximum adsorption capacities for Congo Red (CR, 500 mg g−1), Coomassie Brilliant Blue G 250 (CB, 235 mg g−1), and Malachite Green (MG, 625 mg g−1). The adsorption behaviors of these dyes were fitted by using the Langmuir isotherm model with a high coefficient of determination values ranging from 0.9985 to 0.9969. The adsorption of the three dyes onto FHAP-SH was an endothermic process based on the adsorption thermodynamics model, while the adsorption kinetics analysis of the dyes presented a good alignment with the pseudo-second-order kinetics. The FHAP-SH exhibits a remarkably high adsorption capacity, is inexpensive, and fulfills the ecofriendly requirements of dye wastewater treatment, especially in the textile industry.

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