Dye Adsorption Ability Research Articles

A new monomeric octahedral cadmium(II) complex based on 1,1-bis(3-methyl-4-imidazoline-2-thione)methane ligand with dye adsorption ability

A new cadmium complex with a flexible imidazolinethione ligand has been successfully synthesized. The ligand acts as a bidentate chelating molecule, resulting in the structure being a monomer. In this monomer, cadmium has an octahedral geometry coordinated by four sulfur atoms from two mbit ligands where mbit = 3,3'-methylenebis(1-methyl-1,3-dihydro-2H-imidazole-2-thione) and two oxygen atoms from the DMF molecules. The ClO 4 − anions are uncoordinated and neutralize the positive charge of the cationic complex. The title complex has a good capacity for adsorbing several organic dyes from pollutant solutions.

Synthesis and Characterization of Ni based Metal Organic Framework for Enhancing the Removal of Typical Organic Dyes

In this report we present a simple synthesis of a nickel-based metal organic framework (MOF-Ni) at the room temperature using a solution of dimethylformamide (DMF), ethanol and distilled water. The MOF-Ni synthesized in various solvents displayed numerous different properties and advantages over other materials including easy synthesis procedure, good crystallinity, rigidity, and robust chemical stability. X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and thermal gravimetric analysis (TGA) were employed to analyze the as-synthesized MOF-Ni. The as-obtained MOF-Ni was used to investigate its adsorption kinetics of red telon dye (RTL) molecules. The effects of time (30–270 min), initial RTL concentration (20–300 mg/L), adsorbent dose (2–50 mg), solution pH (2–12), and temperature (10–80 °C) were investigated. The pseudo-first order rate equation was able to provide the best description of the adsorption kinetics data in the studied time scale. The Langmuir and Freundlich adsorption models were applied to describe the equilibrium isotherms, and the isotherm constants were also determined. Dye adsorption turned out to strongly depend on pH, and a low pH was found to increase the amount of adsorbed dyestuff. Compared with other samples, MOF-Ni synthesized in (DMF ​+ ​C2H5OH ​+ ​H2O) had a significantly enhanced adsorption ability for RTL dye. The MOF-Ni high adsorption capacity for RTL dye was attributed to the electrostatic attraction/repulsion phenomena. Moreover, MOF-Ni showed an improved stability at 370, 417, and 423 °C temperatures. The results obtained through our experiments suggested that our porous MOF-Ni microstructures synthesized in DMF ​+ ​C2H5OH ​+ ​H2O have potential applications for treating wastewaters containing RTL dyes.

Effect of conductive polyaniline on the cationic and anionic dye adsorption properties of amphoteric alginate/chitosan composite foams

Doped polyaniline is a widely used conductive material and could be used for adsorption based on the electrostatic neutralization effect through the protonation of the imine group. However, the adsorption effect and mechanism towards cationic and anionic pollutants are not clear. Herein, the conductive sulfonic acid doped polyaniline was introduced into alginate/chitosan amphoteric composite foams prepared with a thermal induced phase separation technique. The composite foams were characterized in terms of scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and electrochemical impedance. The composite foam exhibited rich pores and fibrous matrix due to the unique ternary solvent system. The polyaniline was well-distributed and enhanced the cationic dye adsorption ability, contrary to that of anionic dye. Compared with pure alginate/chitosan composite foam, the adsorption capacity of methylene blue was increased by 91.1%, and that of acid blue-113 was reduced by 49.2%. The adsorption rate of the two dyes was both increased. Polyaniline addition enhances the ionic mobility rate and accelerates the movement of dye molecules. Moreover, the composite foams exhibited excellent selective adsorption capacity and reusability. The study indicates that the conductive polymer could find its share in developing high-performance adsorbents.

Review on emerging trends and challenges in the modification of xanthan gum for various applications

This review explores the realm of structural modifications and broad spectrum of their potential applications, with a special focus on the synthesis of xanthan gum derivatives through graft copolymerization methods. It delves into the creation of these derivatives by attaching functional groups (-OH and –COOH) to xanthan gum, utilizing a variety of initiators for grafting, and examining their diverse applications, especially in the areas of food packaging, pharmaceuticals, wastewater treatment, and antimicrobial activities. Xanthan gum is a biocompatible, biodegradable, less toxic, bioactive, and cost-effective natural polymer derived from Xanthomonas species. The native properties of xanthan gum can be improved by cross-linking, grafting, curing, blending, and various modification techniques. Grafted xanthan gum has excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing ability. Owing to its remarkable properties, such as biocompatibility and its ability to form gels resembling the extracellular matrix of tissues, modified xanthan gum finds extensive utility across biomedicine, engineering, and the food industry. Furthermore, the review also covers various modified derivatives of xanthan gum that exhibit excellent biodegradability, metal binding, dye adsorption, immunological properties, and wound healing abilities. These applications could serve as important resources for a wide range of industries in future product development.

Inorganic–Organic Framework Constructed by the Intercalation of a Double-Decker Porphyrin Metal Complex into Clay Nanosheets and Its Efficient Dye Adsorption Ability

Inorganic–Organic Framework Constructed by the Intercalation of a Double-Decker Porphyrin Metal Complex into Clay Nanosheets and Its Efficient Dye Adsorption Ability

Selective crystal growth of magnesium hydroxide via solvent control for dye adsorption

This study provides a solvent control method for synthesizing Mg(OH)2 with different polarities and improved dye adsorption abilities.

Adsorption Mechanism of Methylene Blue on Purified Red Phosphorus and Effects of Different Temperatures on Methylene Blue Desorption

Purified red phosphorus (RP) can be used as an adsorbent. However, the adsorption mechanism and reuse ability of purified RP have not been reported. This study utilized X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy techniques (a statistical physics model and the standard molar free energy of formation) to investigate the adsorption mechanism of methylene blue (MB) by purified RP. Purification did not change commercial RP structure according to X-ray diffraction. The results showed that the adsorption process only included physical adsorption according to Fourier transform infrared spectroscopy and UV–vis diffuse reflection absorption spectra. The specific areas of commercial RP and purified RP were 0.02 cm3/g and 5.27 cm3/g, respectively. Thus, purified RP has a higher adsorption capacity compared with commercial RP. A statistical physics model showed that, as the temperature increased from 288 to 308 K, the qe, Dm and qsat of purified RP for MB increased from 179.87, 0.824 and 0.824 to 303.26 mg/g, 1.497 mol/kg and 1.497 mol/kg, respectively. The fitted values of ΔrSmθ, ΔrHmθ and ΔrGmθ were 104.38 J·mol−1·K−1, −2.7 × 103 J·mol−1 and negative, respectively. Thus, according to adsorption energy, the adsorption of MB by purified RP was a spontaneous process, which was mainly driven by entropy increasing. Compared with neutral dye, the purified RP had higher adsorption ability for the cationic dye and anionic dye. As the purified RP dose increased from 30 to 150 mg, the adsorption capacity of purified RP increased. However, as the MB concentration and pH increased, the adsorption capacity of purified RP decreased. The purified RP had excellent reuse ability and high temperature desorption can be applied to obtain its reuse ability.

FEASIBILITY STUDY ON PREPARATION OF RICE STRAW NONWOVEN COATED WITH CHITOSAN FOR REACTIVE DYE ADSORPTION

Rice straw is the most abundant agricultural waste material in Thailand. Therefore, this research was interested in utilizing rice straw and adding value by preparing a reactive dye bioadsorbant. The aims of this research were to prepare rice straw nonwovens by the wet-laid process, study chitosan-coated nonwovens by the dip coating method, and evaluate the reactive dye adsorption capacity of the coated nonwovens. The ratio of weight per unit area of the prepared nonwovens was controlled. The nonwovens were dipped in chitosan solutions (0.5, 1, and 1.5 wt% of chitosan) to prepare chitosan coated nonwovens. Reactive dye adsorption capacity, chemical structure, morphology, and physical properties of the nonwovens were investigated. It was found that rice straw nonwoven coated with chitosan increased in thickness, hardness, and water resistance properties with increasing chitosan concentration. Chitosan-coated nonwoven, at 15% chitosan concentration and a contact time of 72 hours, was able to adsorb 38.40% of the reactive azo dye, C.I. Reactive Blue 194 (50 mg/L). The dye absorbency of the chitosan-coated nonwovens increased with the increase in the chitosan-coated concentration and the contact time. In addition, the chitosan-coated nonwovens could remain on rice straw cellulose nonwoven surfaces under reactive dye immersion for at least 72 hours without change. The results indicated that rice straw nonwovens coated with chitosan by the dip coating method had reactive dye adsorption abilities.

Treatment of Direct Red 28 Dye through Phoenix dactylifera L. Fruit Seed Biochar: Equilibrium, Kinetics, Thermodynamics, and Phytotoxicity Studies

Wastewater discharge into aquatic systems has become a severe threat to the ecosystem. Herein, Direct Red 28 (DR28) dye removal from an aqueous solution was executed with the application of date fruit seed biochar (DFSB). Fourier transform infrared spectra (FTIR) and scanning electron microscopy (SEM) were utilized for the identification of functional groups and characteristics of the DFSB surface. A series of batch investigations were conducted to analyze pH, contact duration, biochar amount, dye concentration, temperature, and agitation speed on DR28 dye elimination from an aqueous medium by DFSB. The highest dye elimination, 97%, was recorded at a pH of 3 by DFSB at 250 mg/L DR28 dye concentration. The equilibrium data indicated the best fit with the Langmuir isotherm with R2 = 0.99, showing 5.83 mg/g monolayer DR28 uptake potential. The best correlation coefficient of the sorption procedure was observed with a pseudo-second-order kinetic study. Investigations on thermodynamic variables disclosed favorable, impetuous exothermic processes. The sorption process was spontaneous as well as exothermic, which was reflected by analyses of thermodynamic parameters. DFSB showed a 33% DR28 dye adsorption ability for up to five successive cycles. DFSB-treated DR28 dye solution increased seedling growth and biochemical components of pigeon pea. The results of the present investigation revealed the significant capacity of DFSB for DR28 dye elimination. Date fruit seed biochar can be applied as an environmentally benign, sustainable adsorbent for DR28 dye removal from industrial effluent, as it is available at zero cost and converts wastewater into reusable biomaterial. Thus, the application of DFSB can assist in wastewater treatment, carbon sequestration, and waste management for a sustainable future.

S-scheme heterojunction Cu2V2O7/α-Fe2O3 nanosheets with effective photocatalytic activity toward organic pollutant degradation

Photocatalytic degradation of organic pollutants is a highly promising technology. Here, we design a novel Cu2V2O7/α-Fe2O3 S-scheme heterostructure by a one-step solvothermal method, which is inexpensive, easily accessible, highly solar-light efficient, and environmentally friendly. XPS demonstrates the strong interaction between Cu2V2O7 and α-Fe2O3, and the photoelectricity test verifies the significant enhancement of electrical properties by the heterostructure. DFT calculations illustrate the formation of the solid built-in electric field. The construction of S-scheme heterojunction is confirmed by differential charge density, and the catalytic mechanism is determined. The efficient degradation performance of the new heterojunction was experimentally demonstrated using methylene blue (MB) and tetracycline hydrochloride (TC) as typical organic pollutants. In the study, the β-Cu2V2O7 exhibited better dye adsorption ability, proving its photocatalytic degradation potential. Meanwhile, our study provides new insights into S-scheme heterojunctions and visible light-responsive composites.

Electrospun Nanofiber Membrane: An Efficient and Environmentally Friendly Material for the Removal of Metals and Dyes.

With the rapid development of nanotechnology, electrospun nanofiber membranes (ENM) application and preparation methods have attracted attention. With many advantages such as high specific surface area, obvious interconnected structure, and high porosity, ENM has been widely used in many fields, especially in water treatment, with more advantages. ENM solves the shortcomings of traditional means, such as low efficiency, high energy consumption, and difficulty in recycling, and it is suitable for recycling and treatment of industrial wastewater. This review begins with a description of electrospinning technology, describing the structure, preparation methods, and factors of common ENMs. At the same time, the removal of heavy metal ions and dyes by ENMs is introduced. The mechanism of ENM adsorption on heavy metal ions and dyes is chelation or electrostatic attraction, which has excellent adsorption and filtration ability for heavy metal ions and dyes, and the adsorption capacity of ENMs for heavy metal ions and dyes can be improved by increasing the metal chelation sites. Therefore, this technology and mechanism can be exploited to develop new, better, and more effective separation methods for the removal of harmful pollutants to cope with the gradually increasing water scarcity and pollution. Finally, it is hoped that this review will provide some guidance and direction for research on wastewater treatment and industrial production.

A novel tetrafluoroterephthalonitrile-crosslinked quercetin/chitosan adsorbent and its adsorption properties for dyes

A new tetrafluoroterephthalonitrile crosslinked quercetin/chitosan (T-QT/CS) adsorbent was successfully synthesized for the adsorption of both cationic and anionic dyes in water. The structure of the resulting T-QT/CS was characterized by FTIR, 13CNMR, TGA, BET, SEM, and XPS, and the surface-charge property of the T-QT/CS at different pH values was determined by the zeta potential measurement. It was found that the adsorption behavior of the T-QT/CS for the cationic methylene blue (MB) dye and the anionic orange G (OG) dye conformed to the pseudo-second-order kinetic model and the linear Langmuir isotherm model. Furthermore, basing on the linear Langmuir isotherm model, the T-QT/CS possessed good dye-adsorption ability, and the maximum adsorption capacities of the T-QT/CS for the MB (at pH=9) and OG (at pH=2) at 303 K were 917.4 mg/g and 349.9 mg/g, respectively. The thermodynamic experimental results showed that the MB and OG adsorption processes of the T-QT/CS were endothermic and spontaneous. In addition, the T-QT/CS exhibited good reused ability for the adsorptions of MB and OG even after five adsorption-desorption experiments.

Synthesis of mixed-mode based functionalized mesoporous silica through RAFT polymerization and its application for dye adsorption

The surface characteristics had a huge impact on adsorption effects. In this paper, the functionalized mesoporous silica based on mixed-mode including hydrophobic (π-π stacking) and electrostatic interactions were designed and prepared through reversible-addition fragmentation chain transfer (RAFT) polymerization. Firstly, the styrene and maleic anhydride were alternately copolymerized on the mesoporous silica with high grafting density, and then the carboxyl groups and amino groups were introduced through the ring-opening of maleic anhydride groups, respectively. The adsorption results indicated that the materials showed high adsorption ability for ionic dyes, with maximum adsorption quantity of around 200 mg/g for methylene blue adsorbed by SiO2@poly(MA-ST)-COOH and around 250 mg/g for azophloxine adsorbed by SiO2@poly(MA-ST)-TETA, and the adsorption rate was fast. Besides, through the elution of absorbed methylene blue with 1 mol/L HCl and absorbed azophloxine with 0.1 mol/L NaOH, the desorption efficiency was above 90%, and the adsorbents showed superior reusability. The adsorption mechanism study further proved that the π-π stacking and electrostatic interactions were effectively integrated during the adsorption process. These findings manifested that the materials could effectively remove ionic dyes from wastewater, with advantages of simple preparation, mixed-mode interactions and high adsorption performance, and would be extended to the adsorption treatments of other dyes and heavy metal ions.

Elucidating the adsorption mechanisms of anionic dyes on chitosan (110) surface in aqueous medium by quantum chemical and molecular dynamics

This work reports the molecular dynamic (MD) simulation modeling of the adsorption mechanisms of anionic dyes; tartrazine (TRZ), sunset yellow (SSY), and brilliant blue (BRB) on the chitosan (Chit) (110) surface. Quantum chemical descriptors calculations suggested a strong inclination of chitosan to donate electrons indicating that it can be readily protonated in its nitrogen atoms in an acidic medium, which act as potential interaction sites for the anionic dyes. Simulation results indicated that the adsorption process was performed with a parallel orientation of the dyes on the chitosan (110) surface. The adsorption energies were -8459.71, -5278.01, and -2486.50 kcal/mol for TRZ, SSY, and BRB, respectively. Therefore, the studied biopolymer indicated the highest adsorption ability for TRZ dye (E ad (TRZ-Chit) >E ad (SSY- Chit) > E ad (BRB- Chit)). The ad sorption energy analysis showed that the removal of the studied molecules was an exothermic chemisorption process, which could be governed by steric parameters according to the findings obtained with the MD and quantum chemical descriptors. The radial distribution function (RDF) further confirmed the interactions, wherein the bonding distances between dyes and the chitosan surface were lower than 3.5 Å. The obtained dynamic descriptors results revealed appropriate fitting with experimental data. • Simulation modelling of the adsorption mechanisms of anionic dyes on chitosane (110) surface. • Chitosan can be readily protonated in its nitrogen atoms in acidic medium, which act as potential interaction sites. • Parallel orientation of the dyes on the chitosan (110) surface with bonding distance lower than 3.5 Å • Exothermic chemisorption process governed by steric parameters

Development of immobilised sunlight active W-Mo/Mo-V/V-W co-doped TiO2 photocatalyst by plasma electrolytic oxidation

W-Mo/Mo-V/V-W co-doped TiO2 photocatalyst for the effective degradation of MB (methylene blue) dye under sunlight irradiation was successfully prepared by one-step Plasma Electrolytic Oxidation (PEO) process. The XRD, XPS, and EDS results revealed that W/Mo/V were co-doped in the TiO2 lattice. The highest redshift in the light absorption edge is recorded for the sample MV (Mo-V co-doped TiO2) with a bandgap of 2.51 eV, whereas the bandgaps for WM (W-Mo co-doped TiO2) and VW (V-W co-doped TiO2) are recorded as 2.96 eV and 2.58 eV, respectively. The co-doped photocatalysts show a typical PEO structure with a high degree of porosity favouring the dye adsorption ability. EIS, LSV, and PL analysis confirmed that the co-doped coatings pose a high degree of charge separation, suppressed charge carriers' recombination, and increased the ability to produce photocurrent. Under direct sunlight irradiation, the sample MV showed the highest photocatalytic efficiency, confirmed by MB dye degradation, then the other co-doped and undoped TiO2. This can be attributed to the synergetic effects of intense visible light absorption in the solar spectrum and the reduced charge carriers' recombination rate by acting as the trapping sites for photogenerated electrons and holes. Finally, this immobilised co-doped photocatalyst developed by the PEO process is a promising system in the quest to establish a renewable energy-assisted strategy for textile wastewater treatment application. • Developed direct sunlight active W-Mo/Mo-V/V-W co-doped TiO 2 on Cp-Ti by PEO. • Mo-V co-doped TiO 2 (Eg of 2.41 eV) shows the highest redshift in light absorption. • Immobilised Mo-V co-doped TiO 2 shows the highest dye degradation and mineralisation. • Low Eg and e + /h − recombination rate is due to the synergetic effect of V and Mo.

Sunflower waste – manganese iron oxide composite for hazardous dye removal

Sunflower waste (SF), an easily available agricultural waste was used as a primary material in the synthesis of sunflower waste – manganese iron oxide (SF-MIO) composite for the aim of waste recycling and synthesizing new composite material for dye adsorption. The synthesized adsorbent was characterized using various techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric and differential thermal analysis (TG-DTA) and Brauner-Emmett-Teller (BET) analysis. Dye adsorption ability of the SF-MIO composite in the aqueous solution was investigated using the anionic dye Congo Red (CR). Effect of adsorption parameters such as adsorbent dosage, temperature, initial dye concentration and time were investigated. According to the characterization results, manganese iron oxide addition provided porous microstructure to sunflower waste and increased its surface area from 1.1814 to 47.1415 m2/g thus made sunflower waste more suitable for adsorption. Adsorption process was maintained in endothermic nature and maximum adsorption capacity of SF-MIO on to CR was calculated as 45.66 mg/g. Pseudo-first order, pseudo-second order, Elovich kinetic models and Langmuir, Freundlich, Temkin and Halsey isotherms were studied. The adsorption behavior of CR on SF-MIO composite can be well described by Freundlich and Halsey isotherm models (R2=0.996) and pseudo-second order kinetic model (R2=0.999).

Exploiting one dimensional polymer for environmental monitoring: Co based coordination polymer for efficient removal of cationic dyes

In this work, a one-dimensional (1D) coordination polymer (Co-CP) was synthesized using the solvothermal method. The polymer has been characterized thoroughly via various spectroscopic methods such as FTIR, UV–visible, PXRD and TGA. Single-crystal X-ray investigation revealed the exact structure of the Co-CP. The stability of coordination polymer is due to the formation of H-bonding and π-π interactions, which also enhance the practical application like dye adsorption ability. The dye adsorption investigations conducted on four dyes, i.e., methylene blue (MB), rhodamine-B (Rh–B), methyl orange (MO) and congo red (CR), demonstrated the present material to be selective towards cationic dyes. The Co-CP framework dispenses rapid and efficient removal of cationic dyes (MB and Rh–B) also in the presence of aromatic anionic dyes (MO and CR). Moreover, this adsorbent material shows excellent structural stability and recyclability after four times of adsorption and desorption and the pseudo-second-order kinetic model fit the best in this case. The plausible mechanism for efficient adsorption of cationic dyes is mainly cation–π and π-π interactions existing between the Co-CP and dye molecules. Therefore, the present work opens new doors for the coordination chemists to further tune the structural features to modulate the adsorption or separation efficiency of the simple and low-cost polymer for environmental protection for future efforts.

Characterization of Etched Graphite Nanoplates and Their Nonwoven Electrode Applications

Carbon materials are under the investigative spotlight for their earth-abundance, sustainability, and intriguing electronic properties. Amongst all nano-carbon allotropes, exfoliated graphite nanoplates (xGnP) currently dominate the commercial market due to their low cost and high performance. However, smooth basal planes of xGnP possess limited surface functionality, leading to poor thin film-forming ability and poor adhesion of xGnP with flexible textile substrates. To overcome these issues, here we have proposed a facile acid etching process for localized oxidation of xGnP sheets. The etching process removes some xGnP surface, hence forming pits on xGnP sheets, along with introducing surface functional groups. The functional surface of etched-xGnP facilitates uniform coating on polyester microfiber nonwoven membrane, resulting in a flexible nonwoven structured electrode. The comparison of etched and pristine xGnP electrodes revealed better conductivity, dye adsorption, electrocatalytic activity, and heat generation ability of the etched-xGnP. The higher surface area and oxygen/nitrogen doping incurred during the etching process were observed to play a critical role in the superior performance of etched-xGnP. The facile etching process will advance the understanding and applications of flexible electrodes for wearable electronic devices.

Green synthesis of sorbus pohuashanensis/aronia melanocarpa extracts functionalized ZnO nanoclusters and their applications

ZnO nanoclusters (ZnO NCs) had been widely utilized in optoelectronics, sensors, dye removal, and antibacterial fields. To reduce or avoid the use of toxic, harmful, and costly chemical reagents, the Sorbus pohuashanensis and Aronia melanocarpa extracts were used to green synthesize ZnO NCs with superior adsorption ability for the organic dyes. The obtained ZnO NCs were characterized by UV–vis spectroscopy (UV–vis), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), x-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). TEM and SEM results indicated that the ZnO NCs tended to aggregate into large branching and sheet structures. EDS measurement confirmed the presence of zinc ions on the ZnO NCs. FTIR results revealed that the components of the fruits extracts were bounded on the surface of ZnO NCs. The primary application experiments demonstrated that the Sorbus pohuashanensis and Aronia melanocarpa extracts functionalized ZnO NCs possess effectively removing activity for organic dyes.

Implanting N-doped CQDs into rGO aerogels with diversified applications in microwave absorption and wastewater treatment

In this work, water-soluble nitrogen-doped carbon quantum dots (N-CQDs) were synthesized by a one-step hydrothermal method, and then implanted into graphene aerogels to obtain N-CQDs/rGO composites. Herein, N-CQDs, as connection sites and channels in rGO, can effectively promote electron jumping and migration and greatly enhance the conduction loss of rGO. As expected, the composites exhibit excellent microwave absorption performance with ultra-wide effective absorption bandwidth of 7.36 GHz and ultra-high minimum reflection loss (RLmin) of −69.42 dB at an ultra-low filler loading of 5 wt%. An ultra-low bulk density of the N-CQDs/rGO composite reach as 4.24 mg/cm3. Actually, the outstanding performance of microwave absorption is attributed to the specific surface morphology and porous structure, enhanced conduction loss and good impedance matching. Meanwhile, the as-synthesized composites display the typical selective adsorption ability for dyes in the wastewater, where the maximum adsorption capacity for methylene blue (MB) dyes is 261 mg/g. Briefly, the study provides a new approach on the comprehensive environmental application of CQDs/graphene composites with both high-performance microwave absorption and high-efficiency removal of organic dyes in the wastewater.