One‑ and two‑dimensional carbon nanomaterials as adsorbents of cationic and anionic dyes from aqueous solutions

E. E. Pérez‑Ramírez,M. de la Luz‑Asunción,A. L. Martínez‑Hernández,G. de la Rosa‑Álvarez,S. Fernández‑Tavizón,P. Salas,C. Velasco‑Santos 한국탄소학회 2019 Carbon Letters Vol.29 No.2

One- and two-dimensional carbon nanomaterials were tested as adsorbents for the elimination of two anionic dyes, reactive red 2 and methyl orange, and the cationic dye methylene blue from aqueous solutions under the same conditions. Carbon nanomaterials performed well in the removal of dyes. Surface oxygenated groups in the nanomaterials improved the cationic dyes’ adsorption, but not the adsorption of the anionic dye. The interactions between nanomaterials and dyes were verified by infrared and Raman spectroscopy. The pseudo-second order kinetic model was better fitted to the kinetic experimental data than the Elovich and pseudo-first order models. The equilibrium adsorption data were best fitted by the Langmuir model. The dimensions and morphology of the carbon nanomaterials play an important role in the adsorption of the three dyes. The main mechanism of adsorption of anionic dyes is by the interactions of the aromatic rings of the dye structures and π delocalized electrons on carbon nanostructures; the adsorption of cationic dye is mainly due to electrostatic interactions.

활성탄에 의한 Brilliant Green과 Quinoline Yellow 염료의 흡착에 대한 등온선, 동력학, 열역학 및 경쟁흡착

이종집 ( Jong Jib Lee ) 한국화학공학회 2021 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.59 No.4

활성탄에 의한 Brilliant Green(BG), Quinoline Yellow(QY) 염료의 흡착에 대한 등온선, 동력학, 열역학적 특성치와 경쟁흡착을 흡착제의 양, pH, 초기농도, 접촉시간 및 온도를 변수로 하여 수행하였다. BG와 QY는 가지고 있는 atomic nitrogen 이온(N⁺)의 영향으로 pH 11에서 92.4%의 최고 흡착율을 나타내었고, QY는 sulfite 이온(SO₃^-)의 영향으로 pH3에서 90.9%의 최고 흡착률을 나타냈다. 등온흡착 데이터로부터, BG의 경우는 Freundlich 등온식에 잘 맞아서 다분자층 흡착이었고, QY는 Langmuir 등온식이 가장 높은 일치도를 나타내어 주로 단분자층흡착이었다. Freundlich 식과 Langmuir 식의 분리계수는 활성탄에 의해 이들 염료를 효과적으로 처리할 수 있는 공정임을 나타냈다. Temkin 등온식에 의해 평가된 흡착 에너지는 활성탄에 의한 BG와 QY의 흡착이 물리 흡착임을 확인시켰다. 동력학적 실험결과는 유사 이차 반응속도식이 유사일차 반응속도식보다 일치도가 높았고 평형흡착량에 대한 오차도 더 작았다. 입자내 확산식을 이용하여 도시한 그래프는 2단계의 직선으로 나타났는데 기울기가 낮은 입자내 확산이 율속단계임을 확인하였다. 흡착공정의 활성화 에너지와 엔탈피 변화는 흡착과정이 비교적 수월하게 일어나며 흡열반응임을 나타냈다. 엔트로피 변화는 활성탄에 대한 BG와 QY 염료의 흡착이 진행됨에 따라 흡착시스템의 무질서도가 증가함을 나타냈고, Gibbs자유 에너지 변화로 부터 흡착반응이 온도가 높아질수록 자발성이 더 커진다는 것을 알았다. 혼합용액의 경쟁흡착 결과는 상대적으로 흡착률이 높은 QY가 BG에 의해 큰 방해를 받아 흡착률이 크게 감소하는 것으로 나타났다. Isotherms, kinetics and thermodynamic properties for adsorption of Brilliant Green(BG), Quinoline Yellow(QY) dyes by activated carbon were carried out using variables such as dose of adsorbent, pH, initial concentration, contact time, temperature and competitive. BG showed the highest adsorption rate of 92.4% at pH 11, and QY was adsorbed at 90.9% at pH 3. BG was in good agreement with the Freundlich isothermal model, and QY was well matched with Langmuir model. The separation coefficients of isotherm model indicated that these dyes could be effectively treated by activated carbon. Estimated adsorption energy by Temkin isotherm model indicated that the adsorption of BG and QY by activated carbon is a physical adsorption. The kinetic experimental results showed that the pseudo second order model had a better fit than the pseudo first order model with a smaller in the equilibrium adsorption amount. It was confirmed that surface diffusion was a rate controlling step by the intraparticle diffusion model. The activation energy and enthalpy change of the adsorption process indicated that the adsorption process was a relatively easy endothermic reaction. The entropy change indicated that the disorder of the adsorption system increased as the adsorption of BG and QY dyes to activated carbon proceeded. Gibbs free energy was found that the adsorption reaction became more spontaneous with increasing temperature. As a result of competitive adsorption of the mixed solution, it was found that QY was disturbed by BG and the adsorption reduced.

Single and binary adsorption of dyes from aqueous solutions using functionalized microcrystalline cellulose from cotton fiber

Hongjuan Bai,Junhang Chen,Xiangyu Zhou,Chengzhi Hu 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.11

Simultaneous removal of dyes in the effluents of printing and dyeing industries is challenging, and the mechanism of the co-adsorption of dyes is still unclear. In this context, a novel adsorbent based on microcrystalline cellulose from cotton fiber through a simplified chemical modification process was prepared. Methylene blue (MB) and neutral red (NR) were selected to investigate their adsorption/co-adsorption on such functionalized microcrystalline cellulose. The experimental adsorption results indicated that the adsorption quantity of both dyes was similar for the single solute. The kinetics of adsorption processes could be better described with the pseudo-second order models for both single and binary dye solutes. The results of the co-adsorption suggested that the extended Langmuir model could well predict equilibrium. The maximum adsorption capacity of MB and NR for the single systems was 115.2 and 83.2mg/g, respectively. Moreover, an antagonistic effect could be found in the binary dye solute. The obtained results revealed that the co-adsorption of dyes might be driven by hydrogen bonding, - stacking interaction as well as electrostatic interaction.

Pseudo First-Order Adsorption Kinetics of N719 Dye on TiO₂ Surface

Lee, Chang-Ryul,Kim, Hui-Seon,Jang, In-Hyuk,Im, Jeong-Hyeok,Park, Nam-Gyu American Chemical Society 2011 ACS APPLIED MATERIALS & INTERFACES Vol.3 No.6

<P>We have investigated the adsorption kinetics of Ru-based N719 dye on TiO<SUB>2</SUB> surface in dye-sensitized solar cell using 0.5 mM and 5 mM dye solutions. The amount of adsorbed dye on TiO<SUB>2</SUB> surface of ca. 5 μm-thick film was measured as a function of immersion (adsorption) time. The amount of adsorbed dye increases with increasing the adsorption time and keeps constant after saturation. Completion of dye adsorption is found to be more than 5 times faster in 5 mM than in 0.5 mM. Since the change of dye concentration is negligible compared to that of number of TiO<SUB>2</SUB> adsorption site, reaction order and rate constant can be estimated from a pseudo reaction. Among the zeroth-, first-, and second-order simulation, the observed data follow first order reaction for both 0.5 mM and 5 mM cases. The rate constant is estimated to be 0.504 min<SUP>–1</SUP> for 5 mM and 0.094 min<SUP>–1</SUP> for 0.5 mM, which indicates that completion of dye adsorption is about 5 times shorter in 5 mM than in 0.5 mM. This is consistent with the observed adsorption time difference. Except for the difference in adsorption kinetics, best cell efficiency is similar regardless of dye solution concentration.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/aamick/2011/aamick.2011.3.issue-6/am2001696/production/images/medium/am-2011-001696_0005.gif'></P>

Wool Fabric Dyeing with Natural Dye Extracted from Cinnamomum verum J. Presl Fruit

Fabricio Leal Ferreira,Élvio Antônio de Campos,Washington Luiz Félix Santos,Márcia Gomes da Silva 한국섬유공학회 2023 Fibers and polymers Vol.24 No.12

Given today’s market requirements and the growing awareness of producers and consumers about problems caused by synthetic dyes, natural dyes are a cost-effective and sustainable alternative for textile dyeing since they are highly biodegradable and pose a low risk to the environment and human health. Cinnamomum verum J. Presl is an evergreen tree whose fruit contains anthocyanin derivatives that can be used as a fabric dye. In this study, wool dyeing using natural dye extracted from the fruit of Cinnamomum verum J. Presl was evaluated to determine optimum dyeing conditions, such as temperature, pH level, and dyeing time and dyed samples through color intensity and the potassium alum mordant influence in the fastness to washing of dyed fabric, based on a colorimetric analysis performed in a spectrophotometer using the CIELab system. The conditions that resulted in the highest color intensity were pH 4, 100 °C, and a dyeing time of 60 min and were used to study the dyeing kinetics and balance of the dyeing process based on adsorption isotherms. It was found that the pseudo-second-order kinetic equation best represents the kinetics of wool dyeing and that it involves the chemical adsorption process. The Langmuir–Freundlich adsorption isotherm best fitted the experimental data, indicating that chemical adsorption significantly contributes to a monolayer. The results showed that the extract of Cinnamomum verum J. Presl fruit is a promising natural dye source for wool.

Poly(acrylamide/laponite) nanocomposite hydrogels: Swelling and cationic dye adsorption properties

Li, Peng,Siddaramaiah,Kim, Nam Hoon,Yoo, Gye-Hyoung,Lee, Joong-Hee Wiley Subscription Services, Inc., A Wiley Company 2009 Journal of applied polymer science Vol.111 No.4

<P>Super adsorbent polyacrylamide (PAAm)/nanoclay (laponite, Lap) hydrogels were prepared by in situ free radical polymerization of AAm in an aqueous solution with clay as a crosslinker. The swelling properties and water-soluble cationic dye adsorption behaviors of the PAAm/laponite (PAAm/Lap) nanocomposite (NC) hydrogels were investigated. The parameters of swelling and diffusion of water in dye solutions were evaluated for the PAAm/Lap NC hydrogels. The adsorption behavior of the monovalent cationic dyes such as Basic Blue 12 (BB 12), Basic Blue 9 (BB 9), and Basic Violet 1 (BV 1), were studied on the NC hydrogels. The effects of the clay content of the hydrogel on its cationic dye uptake behavior were studied. The adsorption studies indicated that the rates of dye uptake by the NC hydrogels increased in the following order: BB 9 > BB 12 > BV 1. This order is similar to the swelling results of the PAAm/Lap NC hydrogel in the dye solutions. The equilibrium uptakes of the different dyes by the PAAm/Lap NC hydrogel were nearly the same. In the dye absorption studies, S-type adsorption in the Giles classification system was found for the BB 12 and BV 1 dyes, whereas L-type was observed for the BB 9 dye. After the heat treatment of PAAm/Lap, the rate of dye uptake and equilibrium dye uptake were increased. The NC hydrogels may be considered as a good candidate for environmental applications to retain more water and to remove dyes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009</P>

Inertial impaction and surface diffusion-assisted rapid dye molecule adsorption on TiO₂ thin films for highly efficient dye-sensitized solar cells

Zhang, Yaojia,Kim, Ji Hoon,Luo, Xiuting,Kim, Soo Hyung Elsevier 2018 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.173 No.-

<P><B>Abstract</B></P> <P>An effective and versatile single-stage aerosol impactor was specially designed to rapidly coat the surface of TiO<SUB>2</SUB> thin films with a controlled amount of dye molecules via inertial impaction and surface diffusion to speed-up the manufacturing process and enhance the photovoltaic performance of dye-sensitized solar cells (DSSCs). By theoretically determining the specific dimensions of the aerosol accelerating nozzle and experimentally controlling the mixing ratio between the sheath gas and dye aerosol flow rates in the single-stage aerosol impactor, the speed and quality of dye adsorption on the TiO<SUB>2</SUB> thin films of the photoelectrodes could be systematically assessed in terms of the photovoltaic performance of the DSSCs, including open-circuit voltage, short-circuit current, fill factor, and power conversion efficiency (PCE). It was found that the aerosol impactor-assisted dye coating method developed in this study significantly reduced the duration of dye adsorption (aerosol coating duration = 20–60 min) and increased the PCE of the DSSCs to 7.28%. Using this methodology, dye-coating was ∼20 times faster and the fabricated device has 23% higher PCE compared to the DSSC fabricated by the conventional dip coating method (dip-coating duration = 1200 min, PCE = 5.92%). These results proved that the single-stage aerosol impactor designed in this study is a very effective and versatile device for rapidly coating the surface of TiO<SUB>2</SUB> thin films with dye molecules using sufficient inertial impaction, which enables the introduced dye molecules to infiltrate and quickly adsorb on the surface of TiO<SUB>2</SUB> nanoparticles accumulated in the DSSC photoelectrodes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An aerosol impactor is designed to deposit dye molecules on TiO<SUB>2</SUB> thin films. </LI> <LI> Inertial impaction and diffusion play the important roles of dye adsorption. </LI> <LI> Speed and quality of dye adsorption on TiO<SUB>2</SUB> thin films are considerably improved. </LI> <LI> Dye aerosol-coating-assisted dye-sensitized solar cells (DSSCs) are fabricated. </LI> <LI> The photovoltaic performance of the DSSCs is enhanced. </LI> </UL> </P>

Fast and highly efficient removal of dye from aqueous solution using natural locust bean gum based hydrogels as adsorbent

Pandey, Sadanand,Do, Jeong Yeon,Kim, Joonwoo,Kang, Misook Elsevier 2020 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.143 No.-

<P><B>Abstract</B></P> <P>For the first time, stable LBG-cl-Poly(DMAAm) hydrogel is prepared via free radical in situ polymerization of <I>N</I>, <I>N</I>-dimethyl acrylamide by employing <I>N</I>, <I>N</I>′-methylene bis(acrylamide) as cross-linkers. The hydrogel was characterized by different physicochemical techniques like equilibrium swelling percentage, point of zero charges (pH<SUB>PZC</SUB>), FTIR, SEM, and TGA. The LBG-cl-Poly(DMAAm) hydrogel was used in experiments on swelling behavior and adsorption of water-soluble cationic dye-Brilliant green (BG). The influence of pH on the structural change of BG dye was discussed. The swelling of hydrogel was sensitive toward the pH, ionic strength, and temperature stimuli. Adsorption behavior of hydrogel was investigated for the adsorption of BG dye and it was found to highly efficient in removing 97.7% of BG dye in 50 mg L<SUP>−</SUP> <SUP>1</SUP> of dye solution. Adsorption data displayed that the adsorption of BG followed the pseudo-second-order kinetic model (R<SUP>2</SUP> = 0.998) and Langmuir isotherm model (R<SUP>2</SUP> = 0.988) with a maximum adsorption capacity of 142.85 mg g<SUP>−</SUP> <SUP>1</SUP>. The developed LBG-cl-Poly(DMAAm) hydrogel demonstrated efficient separation of BG dye and maintained maximum adsorption capacity after 6th regeneration cycles. The results indicated that LBG-cl-Poly(DMAAm) hydrogel can be used as an alternative and promising adsorbent to be applied in the treatment of effluents containing the BG dye.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Successful synthesis of highly cost effective locust bean gum based hydrogel </LI> <LI> Influence of pH on the structural change of BG dye </LI> <LI> Thermal analysis showed hydrogel as thermally more stable than natural LBG. </LI> <LI> LBG-cl-Poly(DMAAm) hydrogel shows maximum %G and %SR of 318 and 3200, respectively. </LI> <LI> Hydrogel showed a rapid dye adsorption rate and a high absorption capacity at RT. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Effects of introducing functional groups on the performance of phenoxazine-based dye-sensitized solar cells

Bae, Jong Hyuk,Lim, Seung Ju,Choi, Jun,Yuk, Sim Bum,Namgoong, Jin Woong,Ko, Jae Hoon,Lee, Woosung,Kim, Jae Pil Elsevier 2019 Dyes and pigments Vol.162 No.-

<P><B>Abstract</B></P> <P>Phenoxazine dyes with a hexyloxy chain and furan moiety were synthesized and used in dye-sensitized solar cells. The dyes were designed to investigate the effects of these substituents on the photophysical and electrochemical properties of the dyes and on cell photovoltaic performance. The introduced hexyloxy moiety, as an additional donor, improved the short-circuit current and open-circuit voltage of the cell by increasing light absorption and steric hindrance, respectively. The furan moiety introduced in the phenoxazine dye as a bridge unit led to a bathochromic shift of the absorption band and a large amount of dye adsorption, increasing the short-circuit current of the cell. Among the synthesized dyes, those with the furan moiety showed the best conversion efficiency of 6.34%.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Effects on the cell performance by hexyloxy and furan group introduced on the phenoxazine dye. </LI> <LI> Increase of open-circuit voltage current by suppressing charge recombination. </LI> <LI> Increase of short-circuit current by bathochromic shift and a large amount of dye adsorption. </LI> <LI> The best efficiency was shown by a cell based on the dye with a furan unit. </LI> </UL> </P>

활성탄섬유를 이용한 반응성염료의 흡착 및 THM 생성능의 거동

한명호 ( Myung Ho Han ) 한국수처리학회 2011 한국수처리학회지 Vol.19 No.2

This study was carried out to treat the aqueous solutions containing reactive dyes(RB19, RR120 and RY179) by adsorption process using activated carbon fiber(ACF). And the changes of Trihalomethane Formation Potential(THMFP) in the model experimental system was investigated. ACF(A-15) has much larger specific surface area(1,584m2/g-ACF) in comparison with granular activated carbon adsorbent(F400, 1,125m2/g-GAC), which is commonly used, and most of pores were found to be micropores with pore radius of 2nm and below. It was found that RY179 has highest THMFP, and RB19 was most easily adsorbed among the dyes in this study. Increase and decrease of THMFP concentrations were observed before and after adsorption of reactive dyes on ACF(A-15). THMFPs per unit TOC were significantly decreased after adsorption of reactive dyes. And 70% of THMFP was decreased in adsorbed dye(RY179) solution. In the case of PCP(p-chlorophenol) and sucrose, which are single component adsorbate, adsorption capacities of ACF(A-15) were in good agreement with the batch adsorption measurement, and saturation time predicted of ACF columns for these components was also well agreed with practically measured time. But in the case of reactive dyes, which have relatively high molecular weight and aggregated with multi-components, adsorption capacities or saturation time predicted were not agreed with practically measured values.