scholarly journals Carbene Ligand-Doped Fe2O3 Composite for Rapid Removal of Multiple Dyes under Sunlight

2021 ◽  
Vol 13 (22) ◽  
pp. 12669
Author(s):  
Siwei Yang ◽  
Yichao Zhuang ◽  
Yuanfang Shen ◽  
Weihang Han ◽  
Liangchen Chen ◽  
...  

Contaminated water due to industrial organic dyes presents a significant challenge to sustainability. As a material of green energy, photocatalysts offer an effective and environmentally friendly way to deal with organic dyes for water treatment. A series of simple and highly efficient iron photocatalysts with carbene ligands were developed, which, under the illumination of sunlight, can rapidly degrade multiple organic dyes in water at room temperature, including rhodamine B (RhB), indigo carmine (IC), methyl blue (MB), and congo red (CR). The field-only surface integral method was carried out to determine the absorption spectrum of photocatalyst particles. Under the optimized experimental conditions which were selected by the orthogonal experiments for four dyes, 0.5a@Fe2O3 and 2c@Fe2O3 demonstrated good stability and photocatalytic activity. These two composite materials not only have the ability to remove 98.0% of the degradation in 10 s, but also maintain high reactivity after a few cycles of repeated use.

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1691
Author(s):  
Angela Marotta ◽  
Enrica Luzzi ◽  
Martina Salzano de Luna ◽  
Paolo Aprea ◽  
Veronica Ambrogi ◽  
...  

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.


Author(s):  
Siwei Yang ◽  
Qiang Sun ◽  
Weihang Han ◽  
Yuanfang Shen ◽  
Zhigang Ni ◽  
...  

A simple and high efficient porous composites via the solvent evaporation method using g-C3N4 and NiSO4 was developed. It can super rapidly remove multiple organic dyes in water including rhodamine...


2014 ◽  
Vol 1061-1062 ◽  
pp. 287-290
Author(s):  
Yin Wang ◽  
Zheng Qin Liu ◽  
Kai Qiang Liu ◽  
Cui Ping Zhang ◽  
Qiu Mei Wang

In order to improve the moisture absorption of the acrylic yarn, the acrylic yarn was firstly hydrolyzed in the caustic soda (NaOH) solution to convert the cyano group molecular into hydrophilic group, then the reticulated coatings was formed on fiber surface by chemical crosslink. Furthermore, the effect of the acrylic hydrolysis temperature, NaOH dosage, ethanol, cross-linking agent (CLA) on acrylic affinity for moisture was discussed through the contrast experiments. The best experimental conditions were investigated by the orthogonal experiments, and the optimum process parameters were obtained. The results indicate that under the condition of NaOH concentration of 6%, hydrolysis time of 15 min, temperature of 80°C, and cross-linking agent concentration of 0.09% on weight the yarn (owf), the moisture regain of modified acrylic yarn has increased by 245.4% as compared with that of untreated acrylic yarn and the water absorption has been improved greatly.


Author(s):  
MONIR Z. SAAD ◽  
ATEF AMER ◽  
KHALED ELGENDY ◽  
BASEM ELGENDY

Objective: Two simple, sensitive and accurate spectrophotometric methods have been developed for the determination of sofosbuvir (SOF) and daclatasvir (DAC) in pure forms and pharmaceutical formulations. Methods: The proposed methods are based on the oxidation of SOF and DAC by a known excess of cerium(IV) ammonium nitrate in sulphuric acid medium followed by determination of unreacted cerium(IV) by adding a fixed amount of indigo carmine (IC) and alizarin red S (ARS) dyes followed by measuring the absorbance at 610 and 360 nm, respectively. The experimental conditions affecting the reaction were studied and optimized. Results: The beer’s law was obeyed in the concentration ranges of 0.2-3.0, 0.2-4.0 for SOF and 0.5-4.5 and 0.5-5.0 μg/ml for DAC using IC and ARS methods, respectively with a correlation coefficient ≥ 0.9991. The calculated molar absorptivity values are 2.354 × 104, 1.933 × 104 for SOF and 1.786 × 104 and 2.015 × 104 L/mol. cm for DAC using IC and ARS methods, respectively u. The limits of detection and quantification are also reported. Intra-day and inter-day precision and accuracy of the methods have been evaluated. Conclusion: The methods were successfully applied to the assay of SOF and DAC in tablets and the results were statistically compared with those of the reference method by applying Student’s t-test and F-test. No interference was observed from the common tablet excipients. The accuracy and reliability of the methods were further ascertained by performing recovery studies using the standard addition method.


2021 ◽  
Vol 1019 ◽  
pp. 194-204
Author(s):  
S. Sudhaparimala ◽  
R. Usha

Graphene, functionalized with the heteroatoms like nitrogen, oxygen and sulphur atoms has been well explored for a wide range of applications but only few reports are available on its adsorption and photocatalytic application in the degradation of chlorophenols and organic dyes. A simple and energy-efficient process to prepare graphene oxide and sulphur doped graphene oxide was developed. The micro structure and surface morphology were confirmed by the analytical techniques of Powder X-ray diffractogram (PXRD), Fourier Transformed Raman Spectroscopy (FT-Raman), Scanning Electron Microscopy. The results were suggestive of the structures suitable for screening their catalytic activity in the degradation of the highly toxic polychlorophenols and organic dyes. The adsorption and photo catalytic properties of the asprepared samples were screened for the degradation process and it was found that sulphur doped graphene oxide showed more positive results for the degradation of chlorophenols than graphene oxide. Under the given experimental conditions the decoloration of dyes were not satisfactory. Ultimately, the study provided an economical and efficient, method for tuning graphene structures for the removal of pollutants in wastewater.


NANO ◽  
2021 ◽  
pp. 2150068
Author(s):  
Zhao Yang ◽  
Zhongwei Zhao ◽  
Xuan Yang ◽  
Zongli Ren

For the treatment of dye wastewater, it is of great significance to develop new adsorbents with high adsorption capacity and good separation effect. In this study, the Fe-Co magnetic activated carbon material (CN-Fe-Co-AC) was first prepared by high-temperature calcination. CN-Fe-Co-AC is physically characterized by various methods. CN-Fe-Co-AC can efficiently and quickly remove the organic dyes methylene blue (MB) and acid blue 80 (AB80). The adsorption of MB and acid blue based on CN-Fe-Co-AC adsorbent is mainly through the specific surface area and the functional groups on the surface. During this recovery process, the adsorption activity of CN-Fe-Co-AC for MB and AB80 decreased slightly. Kinetic data can be described using a Pseudo-second-order model and the data for adsorption equilibrium can be described using the Langmuir isotherm. The theoretical adsorption capacities of MB and AB80 are 104.82[Formula: see text]mg/g and 26.94[Formula: see text]mg/g, respectively. After repeated use of five times, the removal rate of MB exceeded 96%, and the removal rate of AB80 exceeded 75%. The excellent adsorption performance and recyclability of CN-Fe-Co-AC indicate that this material has certain potential application value.


2020 ◽  
Vol 53 (6) ◽  
Author(s):  
Frank Winnefeld ◽  
Gregor J. G. Gluth ◽  
Susan A. Bernal ◽  
Maria C. Bignozzi ◽  
Lorenza Carabba ◽  
...  

AbstractThe RILEM technical committee TC 247-DTA ‘Durability Testing of Alkali-Activated Materials’ conducted a round robin testing programme to determine the validity of various durability testing methods, originally developed for Portland cement based-concretes, for the assessment of the durability of alkali-activated concretes. The outcomes of the round robin tests evaluating sulfate resistance, alkali-silica reaction (ASR) and freeze–thaw resistance are presented in this contribution. Five different alkali-activated concretes, based on ground granulated blast furnace slag, fly ash, or metakaolin were investigated. The extent of sulfate damage to concretes based on slag or fly ash seems to be limited when exposed to an Na2SO4 solution. The mixture based on metakaolin showed an excessive, very early expansion, followed by a dimensionally stable period, which cannot be explained at present. In the slag-based concretes, MgSO4 caused more expansion and visual damage than Na2SO4; however, the expansion limits defined in the respective standards were not exceeded. Both the ASTM C1293 and RILEM AAR-3.1 test methods for the determination of ASR expansion appear to give essentially reliable identification of expansion caused by highly reactive aggregates. Alkali-activated materials in combination with an unreactive or potentially expansive aggregate were in no case seen to cause larger expansions; only the aggregates of known very high reactivity were seen to be problematic. The results of freeze–thaw testing (with/without deicing salts) of alkali-activated concretes suggest an important influence of the curing conditions and experimental conditions on the test outcomes, which need to be understood before the tests can be reliably applied and interpreted.


2016 ◽  
Vol 855 ◽  
pp. 45-57 ◽  
Author(s):  
Kalithasan Natarajan ◽  
Rukshana I. Kureshy ◽  
Hari C. Bajaj ◽  
Rajesh J. Tayade

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


RSC Advances ◽  
2016 ◽  
Vol 6 (79) ◽  
pp. 75347-75358 ◽  
Author(s):  
Bibhutibhushan Show ◽  
Nillohit Mukherjee ◽  
Anup Mondal

Hematite α-Fe2O3 thin films have been deposited on FTO coated glass substrates. The films were found to perform efficiently towards electrochemical sensing of methanol and photodegradation of toxic dyes, viz. Indigo Carmine and Rhodamine B.


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