Mesoporous carbon derived from a biopolymer and a clay: Preparation, characterization and application for an organochlorine pesticide adsorption

doi:10.1016/j.micromeso.2016.01.012

Microporous and Mesoporous Materials

Volume 225, 1 May 2016, Pages 342-354

https://doi.org/10.1016/j.micromeso.2016.01.012 Get rights and content

Highlights

•
A carbonaceous material (PCM) was synthesized based on a clay-starch composite.
•
The mesoporous PCM material presents a total surface area of about 870 m² g⁻¹.
•
The PCM potential as adsorbent was evaluated through Dicamba herbicide adsorption.

Abstract

The production of carbon-based materials is a field of intense scientific research due to the diversity of potential applications that this kind of material presents. In this paper, it is reported the synthesis of porous carbonaceous material (PCM) based on the pyrolysis at 850 °C of a composite made of Laponite (commercially available synthetic clay) and Cassava starch, followed by clay removal through acid digestion. The Laponite presence influenced the structural order and textural properties of the pyrolytic carbon formed. After pyrolysis and acid digestion of clay, it was obtained a material with a partial graphitic structure containing majorly sp² bounded carbon atoms, that has almost twice the specific surface area and up to 20 times more mesopore volume than the carbonaceous material obtained without the clay. The adsorbent potential of PCM was evaluated by adsorption of Dicamba, an organochlorine pesticide, from aqueous solutions. The PCM exhibits a high Dicamba removal efficiency, with a maximum adsorption capacity of 251.9 mg g⁻¹ related to a pseudo-second-order kinetic adsorption model with a strong pH dependence.

Graphical abstract

Introduction

The growing demand for multifunctional materials has encouraged the scientific community to investigate the production of new carbon-based materials such as fullerenes, nanotubes, nanostructured porous carbon and carbon nanofibers [1], [2], [3], [4], [5], [6]. These solids can exhibit high specific surface area, mechanical strength, heat resistance, electrical conductivity, among others properties [7], [8], [9], [10], [11], which allow the application of these materials as catalysts, catalyst supports, modified electrodes, fuel cells, supercapacitors and adsorbents [12], [13], [14], [15], [16], [17], [18], [19], [20], [21]. Some types of carbon materials are obtained by using an inorganic template, which allows the control of the structure. These materials are known as nanostructured porous carbons. By removing the template, by acid digestion for example, after carbonization/graphitization of the organic precursor, it gives rise to a porous carbon structure that is the inverse replica of template, named as carbon replicas [22], [23], [24], [25], [26]. Considering only the universe of inorganic templates, they can be classified in two types of templates: the endotemplates, such as silica particles of defined shape and the exotemplates, composed of porous structures such as zeolites, clays and mesoporous silica [25], [26], [27], [28], [29], [30], [31], [32], [33], [34], [35], [36], [37], [38].

Smectite clays, such as montmorillonite, saponite, and hectorite, are highlighted inorganic templates for the carbon materials synthesis due to theirs structural and chemical properties and lower cost compared to the other porous inorganic templates [30], [35], [36], [37], [38]. Kyotani et al. were the forerunners in producing highly oriented graphite using acrylonitrile as carbon source and the montmorillonite clay as template [35]. The acrylonitrile interleaved in the interlayer spacing of montmorillonite was polymerized to poly(acrylonitrile) by using γ irradiation and then the material was heated to 700 °C under N₂ atmosphere for carbonization. The carbon material was obtained after acid digestion of the template and thermal treatments at different temperatures up to 2800 °C.

Among clays, a synthetic hectorite, known as Laponite, is an interesting material to be used as template for mesoporous carbons synthesis, since it is available on the market at costs lower than mesoporous silicas, has a high phase purity and is composed of small-sized particles that are easy to exfoliate in water medium. The hectorite layered structure is composed of three-sheet layers, wherein each layer consists of two outer sheets built up by tetrahedral -[SiO₄]- units and one internal central sheet built up by -[MgO₆]- octahedral units. The isomorphic substitution of magnesium ions in the internal central sheet by lithium ions results in a positive charge deficiency in the layers; the electrical neutrality is achieved by the intercalation of water solvated cations between adjacent layers. The hectorite general chemical composition is $M_{x / n}^{+} [M g_{6 - x} L i_{x}] [S i_{8}] O_{20} {(O H)}_{4} \cdot n H_{2} O$ , where M⁺ represents a monovalent metal cation and x corresponds to the degree of isomorphic substitution (typically between 0.5 and 1.3). The scheme of the Laponite structure is shown in Fig. 1.

The Laponite used in this work has sodium ions between the layers, x equal to 0.7, estimated surface area of 370 m² g⁻¹, particles with a disk-like shape and dimensions of about 25–30 nm of diameter and 1 nm of thickness [39].

Different organic sources have been used as precursor to carbon materials such as alcohols, ionic surfactants, polymers, disaccharides and biopolymers [40], [41], [42], [43]. Biopolymers are an interesting choice of carbon precursors due to theirs renewable origin [44]. Among the various existing ones, the cassava starch derived from Manihot esculenta crantz stands out as an attractive option because it is produced in large quantities at low cost. Cassava plantations require low treatment of the planted area, have high resistance to pests and the highest yield per acreage, which are particularities usually not seen in other crops [45].

The starch structure consists basically of two types of polysaccharides, amylose and amylopectin [46]. The ratio between these polysaccharides in the structure differs depending on the cassava variety, but it is usually between 20% and 80%, respectively. Amylose (Fig. 2a) is a linear molecule composed of d-glucose units linked by α(1 → 4) glycosidic bonds, while amylopectin (Fig. 2b) is a highly branched molecule composed of d-glucose units linked at α(1 → 4) and α(1 → 6) glycosidic bonds at the branching points.

The present paper deals with the synthesis and characterization of a porous carbonaceous material (abbreviated PCM) produced from sodium hectorite and cassava starch through an easily applied procedure. The materials produced were characterized by a series of techniques, among which were powder X-ray diffraction (XRD), thermogravimetry coupled with and mass spectrometry (TGA-MS) photoelectron spectroscopic analysis (XPS), scanning and transmission electron microscopies (SEM, TEM), medium-sized pore distribution and zeta potential analysis. The adsorptive properties of the produced PCM was evaluated in the removal of Dicamba (3,6-dichloro-methoxybenzoic acid) from aqueous solution. This herbicide has high potential for genetic toxicity and it is widely used in agriculture for the controlling of broadleaf weeds [47]. Due to its high water solubility and low volatility, it is easily leached to the environment, polluting water bodies.

Section snippets

Experimental

All reagents used in this work were analytical grade and used as received. The sodium hectorite Laponite RD (Lap) was provided from Laporte Industries (UK). The pesticide Dicamba Pestanal^® was purchased from Sigma–Aldrich. The cassava starch (Cas) was purchased from the Amafil^® Company (Brazil).

Characterization of solids

The pristine cassava starch presents diffraction peaks at 2θ region between 15 and 25° (Fig. 4a) that are associated with a hierarchical organization of amylopectin chains throughout the grain [48]. The peaks at (2θ) 15.2, 17.1, 17.9, and 23.0° are characteristic of a Type-A structure [49]. However, a small peak observed at (2θ) 20° is characteristic of Type-B crystalline structure, indicating that cassava starch is actually a combination of these two crystalline types, known as Type-C [50].

Conclusion

This work presented the synthesis and characterization of a new mesoporous carbonaceous material (PCM) produced from synthetic hectorite (commercially available) and cassava starch. XRD suggests the formation of preferentially intercalated Cas-Lap composite. The presence of layered material affected deeply physicochemical and morphological properties of the pyrolyzed biomass. Ordered graphitic structures comprised mainly of Csp² were obtained for PCM according to XPS, Raman and TEM techniques,

Acknowledgments

Marina de Carvalho Eufrásio Pinto thanks the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES for the Master's scholarship received. The authors also thank the Fundação de Amparo à Pesquisa do Estado de Minas Gerais – Fapemig (Project: APQ-00706-11), the Fundação de Amparo à Pesquisa do Estado de São Paulo – Fapesp (Grant 2011/50318-1), and the Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq (Project 312384/2013-0), for the financial support. The authors

References (85)

H.P. Boehm
Carbon
(1997)
P. Serp et al.
Appl. Catal. A-Gen.
(2003)
W. Nakanishi et al.
Nano Today
(2014)
A. Vinu et al.
Microporous Mesoporous Mater.
(2007)
W.Y. Li et al.
Carbon
(2011)
J. Qi et al.
Carbon
(2012)
B.Y. Wei et al.
Mater. Chem. Phys.
(2003)
S. Bhattacharyya et al.
Carbon
(2008)
X. Mao et al.
Nano Today
(2014)
J. Tang et al.
Nano Today
(2014)

T. Stimpfling et al.

Appl. Clay Sci.

(2010)

W. Stober et al.

J. Colloid Interface Sci.

(1968)

K. Böhme et al.

Carbon

(2005)

C. Santos et al.

Carbon

(2010)

J. Pires et al.

Microporous Mesoporous Mater.

(2004)

B. Liu et al.

Carbon

(2010)

S. Yoon et al.

Mater. Res. Bull.

(2009)

R.V.R.A. Rios et al.

Carbon

(2006)

K. Laohaphatanaleart et al.

Int. J. Biol. Macromol.

(2010)

D.J. Gallant et al.

Carbohyd. Polym.

(1997)

P. Jiping et al.

Food Chem.

(2007)

G.F. Perotti et al.

Polymer

(2011)

G. Leofanti et al.

Catal. Today

(1998)

Y. Ahmad et al.

J. Fluor. Chem.

(2014)

P.K. Chu et al.

Mater. Chem. Phys.

(2006)

H. Darmstadt et al.

Carbon

(2002)

M.C. Tonucci et al.

Ind. Crops Prod.

(2015)

M.J. Carrizosa et al.

Appl. Clay Sci.

(2001)

Z. Aksu et al.

Sep. Purif. Technol.

(2004)

V.O. Njoku et al.

J. Environ. Manage.

(2015)

J.M. Salman et al.

Desalination

(2010)

M.Z. Momcilovic et al.

Chem. Eng. J.

(2013)

V.O. Njoku et al.

Chem. Eng. J.

(2013)

H.W. Kroto et al.

Nature

(1985)

J. Lee et al.

Adv. Mater.

(2006)

A.K. Geim et al.

Nat. Mater.

(2007)

F. Li et al.

Appl. Phys. Lett.

(2000)

D.A.C. Brownson et al.

Analyst

(2010)

S. Yoon et al.

J. Electrochem. Soc.

(2000)

D. Jariwala et al.

Chem. Soc. Rev.

(2013)

F.J. Liu et al.

J. Mater. Chem.

(2012)

G.S. Chai et al.

Adv. Mater.

(2004)

Cited by (38)

Use of biopolymers in wastewater treatment: A brief review of current trends and prospects
2023, Chinese Journal of Chemical Engineering
Indeed, polymeric materials have thrived in worldwide sectors over the last five decades due to their versatility and durability, to the point that we can no longer envisage a product that does not contain them. However, many synthetic polymers that have been produced are mostly sourced from petroleum and coal as raw materials, making them environmentally incompatible because they cannot be integrated with what is a natural recycling system. One of the most important aspects of the transition to a circular bioeconomy (CBE) is the provision of more sustainable strategies for resource and waste management. Considering the environmental consequences associated with petroleum-based polymers (PBPs), natural biopolymers, originating from biomass, can be conceived as a promising solution to gradually replace the PBPs, and address, and resolve the potential challenges and prevailing research gaps in the PBPs. The biopolymers have significant advantages over PBPs in terms of low-cost/zero-cost precursors, environmental friendliness, and user-friendliness. The present review dissects the sources, synthesis pathways, structures, characterization, and employment of biopolymers and their composites in water and wastewater treatment applications via different scenarios. Furthermore, the CBE model framework proposes potential approaches to applying CBE principles in the wastewater management sector, with a heavy emphasis on not only technology but also organizational and societal reforms. To sum up, the reliance on biopolymers can be considered a crucial tool for assessing the global progress toward CBE, as well as future environmental management and planning.
A detailed study on the selection of borderline features for accurate mechanism description of the adsorption of different pesticide molecules under different temperature ranges
2023, Journal of Molecular Liquids
Mathematical models play a crucial role in data acquisition by boosting the capacity to interpret and group the gathered information. However, the challenge lies in choosing the most accurate model to represent data sets with very slight nuances, as it occurs in the validation of adsorption processes considering molecules with different properties but similar structural attributes. Due to these very small variations, there is a high chance of excessive adaption to specific patterns created by the distributions, statistically blindsiding the decision-making. In this work, we used statistical physics (sta-phy) modeling and thermodynamic calculations of the three different pesticides 2,4-dichlorophenoxyacetic acid (2,4-D), dicamba (DCB), and mecoprop (MCPP) on a woody based activated carbon (WBAC) to demonstrate these patterns while also unveiling the mechanisms involved. We demonstrate that the statistical criteria alone do not provide enough clarity in these cases, and we propose using the physical meaning of each estimated parameter as a way out. Thus, in this work, we prove in detail that using sta-phy models requires absolute mastering of the subjects to ensure reliable results by understanding the relationships between the adsorption parameters and the system properties instead of a simple read of the determination coefficients.
Adsorptive properties of the pesticides 2,4-D, mecoprop, and dicamba on a pinus-based biochar: Conventional and statistical physics evaluation
2023, Chemical Engineering Journal
The adsorptive properties of the pesticides 2,4-D, mecoprop, and dicamba on a pinus-based biochar were scrutinized from conventional and statistical physics approaches. Firstly, the pinus-based biochar was prepared from Pinus elliottii and extensively characterized. Then, the conventional adsorption studies were made using kinetic equilibrium and thermodynamics. Subsequently, the statistical physics model of Hill was used to interpret the data. Finally, the pinus-biochar was used to uptake the pesticides from a real river water sample. The results revealed that the pinus-biochar is a rich-carbon material (carbon content higher than 99%) with high thermal stability, interesting textural features, and proper characteristics to effectively uptake small and polar organic molecules. At a pH of 7.0 and using 1.0 g/L, the biochar reduced the concentration of pesticide solutions from 50 μg/L to less than 4.0 μg/L in 2 h of operation. The conventional evaluation revealed that the General order model properly represented the kinetic profile of the pesticides adsorption, while the Langmuir model better represented the isotherms. The maximum uptakes of 2,4-D, mecoprop, and dicamba at 298 K were 100.9 μg g⁻¹, 122.5 μg g⁻¹, and 95.9 μg g⁻¹. The statistical physics model of Hill could explain the adsorption of all pesticides, and new insights were proposed for the adsorption mechanism. The pinus-based biochar was also efficient in decontaminating river waters containing the pesticides, using 5.0 g/L. Finally, it can be concluded that pinus-based biochar is a rich-carbon material able to efficiently uptake the pesticides 2,4-D, mecoprop, and dicamba from synthetic and natural waters. The efficiency, even in a concentration range of μg/L, was attributed to the intrinsic features of the new material.
Highly porous CuZnAl layered double hydroxides prepared by biochar-templated co-precipitation method as catalysts for the preferential oxidation of CO reaction
2023, Applied Clay Science
This study evaluates the effect of the porosity of Layered Double Hydroxide (LDH) containing copper (Cu), zinc (Zn), and aluminum (Al) synthesized by a co-precipitation method with biochar as a hard template on the preferential oxidation of CO (CO-PROX) reaction. Experimental data showed biochar as a hard template promoted structural changes in the LDH, such as 9 to 42 nm increase in pore size, decrease in the copper oxide crystallite size, and increase in metallic area, and enhanced its activity in the CO-PROX reaction. In situ DRIFTS analyses revealed CO was adsorbed on both Cu⁺ and Cu⁰ sites and Cu⁺ was the main species during the reaction for all catalysts.
Environmental-friendly hydrochar-montmorillonite composite for efficient catalytic degradation of dicamba and alleviating its damage to crops
2023, Science of the Total Environment
Citation Excerpt :
Thus, it is particularly timely to explore effective methods to eliminate DIC residues and reduce its negative effects on the agricultural environment. Up to now, there are some treatment methods to remove DIC, such as adsorption (Pinto et al., 2018; Pinto et al., 2016), advanced oxidation processes (AOPs) (Montañez et al., 2015a, 2015b), and biodegradation (Ghoshdastidar and Tong, 2013; González-Cuna et al., 2016), etc. Among these methods, AOPs are identified as a highly efficient approach to degrade persistent organic pollutants for their excellent performance (Ghanbari and Moradi, 2017).
In recent years, carbon-based materials catalyzing peroxymonosulfate (PMS) for green degradation of persistent organic pollutants have attracted increasing attention. However, PMS activation by hydrochar composite (e.g. hydrochar-montomorillonite) has rarely been investigated. Herein, a simple preparation, low-cost and eco-friendly catalyst of hydrochar-montmorillonite composite (HC-Mt) was prepared to firstly catalyze PMS for the degradation of dicamba (DIC). The as-prepared HC-Mt showed a remarkably better catalyzing performance for PMS than pure hydrochar (HC) due to its good physicochemical characteristics and abundant oxygen-containing groups. Furthermore, the electron spin resonance (ESR) and quenching tests revealed that active species such as SO₄^–, OH and O₂^– all participated in the degradation process. DIC sites on C6, Cl 10, and O15 exhibited higher reactivity according to the density functional theory (DFT) calculation, which were easily attacked by active species. The DIC degradation mainly occurred via hydroxyl substitution, decarboxylation, oxidation and ring-cleavage and finally most of the intermediates were mineralized into CO₂ and H₂O. Finally, the phytotoxicity assessment was measured by the germination growth situation of tobacco and mung beans in the presence of DIC (with or without treatment by HC-Mt/PMS). The result showed that HC-Mt/PMS could significantly reduce the phytotoxicity of DIC to crops, suggesting that catalyzing PMS using HC-Mt was environmentally friendly. Therefore, this work did not only provide a novel catalyzing PMS strategy using hydrochar composite for wastewater treatment, but also give a new idea for herbicide phytotoxicity management.
Adsorption of organic pollutants from pesticides using polymeric adsorbents
2023, Polymeric Adsorbents: Characterization, Properties, Applications, and Modelling
Because of the vast amounts of pesticides applied in agriculture, ground- and surface water have been contaminated. As a result of pesticides widely used in agriculture, residues found in rivers, lakes, seas, soils, groundwater, and even drinking water, provide evidence that these chemicals pose a high risk to human health, and toxicity to nontarget organisms. This chapter examined the adsorption capacities of chemical compounds in pesticides in aqueous solutions onto polymeric adsorbents.

View all citing articles on Scopus

View full text

Mesoporous carbon derived from a biopolymer and a clay: Preparation, characterization and application for an organochlorine pesticide adsorption

Highlights

Abstract

Graphical abstract

Introduction

Section snippets

Experimental

Characterization of solids

Conclusion

Acknowledgments

Carbon

Appl. Catal. A-Gen.

Nano Today

Microporous Mesoporous Mater.

Carbon

Carbon

Mater. Chem. Phys.

Carbon

Nano Today

Nano Today

Appl. Clay Sci.

J. Colloid Interface Sci.

Carbon

Carbon

Microporous Mesoporous Mater.

Carbon

Mater. Res. Bull.

Carbon

Int. J. Biol. Macromol.

Carbohyd. Polym.

Food Chem.

Polymer

Catal. Today

J. Fluor. Chem.

Mater. Chem. Phys.

Carbon

Ind. Crops Prod.

Appl. Clay Sci.

Sep. Purif. Technol.

J. Environ. Manage.

Desalination

Chem. Eng. J.

Chem. Eng. J.

Nature

Adv. Mater.

Nat. Mater.

Appl. Phys. Lett.

Analyst

J. Electrochem. Soc.

Chem. Soc. Rev.

J. Mater. Chem.

Adv. Mater.