Worldwide, concerning the growing civilization and huge economic growth through the development of different industry sectors, one of the most important subjects of concern including the hydrosphere. Especially, the water on the planet is contaminated hugely day by day by the effluents produced by industries like dyes, chemicals, pathogenic micro-organisms, etc. giving special attention to this, Dutta and his group in 2022 synthesized heterostructured nanocomposites of GO/Ag2O at room temperature with the purpose to manage industrial wastes. The development showed good absorptivity covering the entire solar spectrum, i.e., 200–1800 nm, and also exhibited an absorption maximum at 700 nm, i.e., blue shifting due to the presence of multiple energy states confirmed by the DFT study. Including this, it was also found to have unique optical properties. It was found to degrade Safranin-O type of dye within 40 mins under white light exposures. Additionally, the nanocomposites also found to possess strong antibacterial activity towards E.coli with MBC = ~ 0.01 mg/ml. The potentiality of the nanocomposites was established by the strong interaction of bacterial membrane and ribosomal protein with GO nanocomposites, as confirmed by molecular docking analysis. The developed nanocomposites were also found to have excellently unfolded solar photocatalytic efficacy and have the tendency to generate the ROS species to obliterate the bacterial colonies under its increasing production of superoxide and hydroxide radicals through fast charge transfer between GO and Ag2O. Thus, the dual purpose of serving nanocomposites acts as an efficient solar photocatalyst and works as a superior antibacterial agent to reject dyes and harmful wastes from contaminated water (Dutta et al. 2022).
The Soltani research group has successfully produced a new LDH/MOF NC in an RB flask under atmospheric pressure for the first time, utilizing an environmentally friendly, effective, and simple in situ technique. At 100 degrees Celsius in a water system, MOF nanocrystals (UiO-66-(Zr)- (COOH)2) were inserted onto and grown evenly across the entire surface of micrometer-sized ultrathin nanosheets of carboxylic acid-functionalized layered double hydroxidenanosheets in a typical solvothermal situation (Ni50Co50-LDH-COOH) (Fig. 2) ( Soltani, et al. 2021).
Bao et al. employed a two-step hydrothermal process to create a ZnO-doped TiO2/reduced graphene oxide (ZnO-TiO2/rGO) nanocomposite for methylene blue adsorption and photodegradation in aqueous medium under UV irradiation. (Fig.) Organic dyes can be adsorbed and photodegraded in water using nanocomposite. After five successive experiments, the empirical data confirmed the great reusability and recovery of ZnO-TiO2/rGO. ZnO-TiO2/rGO to photodegrade micropollutants in the aqueous medium provides a greener and more efficient way for wastewater treatment (Bao et al. 2021).
With an intention to synthesize a biocompatible, stable, cost-effective with improved functionality and eco-friendly nanocomposite for the treatment of contaminated water, the authors had taken the adventure of nature. In this work, they reported the formation of a green nanocomposite that is formed by the zeolite (an organic matrix) encapsulation of magnetic nanoparticles. The use of natural salt provided a considerable amount of dispersibility and chemical stability to the nanocomposite and avoided oxidation. The bioderived magnetite nanoparticles were synthesized using the aqueous leaf extracts of Cordia Africana and was encapsulated by a naturalist (NAT) as an adsorbent. The nanocomposite was used for the adsorption of MB, an organic dye from the aqueous medium under UV irradiation. The prepared M/NAT-NC nanocomposites were characterized by FTIR, XRD, SEM, etc. The efficacy of the nanocomposite different parameters such as concentration of dye, contact time, temperature, pH and adsorbent storage, etc., was estimated by Response Surface Methodology (RSM) -based Box-Behnken Design (BBD). The nanocomposite was 98.6% of maximum adsorption efficiency at 40 min, pH = 9, 0.5 g M/NAT-NCs, 40 mg/L. The adsorption results were best fitted into the Freundlich model and found to follow pseudo 2nd order adsorption kinetics. The negative value of Gibb's free energy confirmed the feasibility and spontaneity associated with the nanocomposites towards MB adsorption. Thus, the nanocomposites can successfully apply to the exclusion of cationic dyes from the aqueous medium (Zenebe et al 2021).
The group of Syed Shahabuddin in 2021 introduced a metal oxide doped polyaniline (PANI) an intrinsically conducting polymer (ICP, an organic macromolecule hybrid which includes the properties of both metal and conventional polymer) based nanocomposite. This was prepared by involving oxidative polymerization strategies for photocatalysis and supercapacitor purposes. Generated nanocomposites were characterized by different spectroscopic analyses such as FE-SEM, TEM, FTIR, XRD, TGA, and BET analyses. Nanocomposites were studied for their photocatalytic efficacies by observing the degradation of industrial dyes under UV irradiations, and the property of supercapacitor was checked by virtue of electrode fabrication to analyze the electrochemical efficiency. The conducting polymer doped nanocomposite was found to have superior capacitance and photocatalytic abilities as compared to that of native polyaniline (PANI). The simple process of synthesis, low manufacturing cost, and improved electroanalytical and photocatalytic performance were the marvelous features associated with the development of naocomposites, making them an alternative choice for waste water treatment and energy storage (Shahabuddin et al. 2021).
Habib Etemadi and his group 2021 disclosed a new approach to wastewater treatment. The group developed a coagulant (poly aluminum chloride) to check its effect on the antifouling ability of the polyvinyl chloride (PVC)/alumina (Al2O3) nanocomposite membrane in a submerged membrane system. The synthesized nanocomposite membranes were characterized through spectral analyses such as FE-SEM, contact angle, AFM, and pure water flux (PWF). The membrane composed of a 98.5/1.5 ratio of PVC to Al2O3 was associated with a number of interesting features, including high rates of porosity, hydrophilicity, and PWF over other membranes. The presence of Al2O3 nanoparticles on PVC membrane was founded to create macro voids and large pores on the surface and a cross-section of the membrane compared to bare PVC membrane as depicted by FE-SEM analysis.
Similarly, the surface roughness of the nanocomposite membrane over bare PVC membrane were predicted through the AFM study. The antifouling performance was checked by the ability of its humic acid (HA) filtration from the water solution with and without additive (PAC coagulant). The antifouling behavior of the membrane was found to be decreased sharply from 60.7–19.4% in the absence of additive, but showed a superior efficacy of around 90.5% towards HA filtration. Thus, the presence of PAC coagulant had significantly improved the antifouling ability and HA filtration from the damaged water via the formation of cake which was confirmed by the Hermia model (Etemadi et al. 2021).
The development of a cost-effective, stable, and recyclable adsorbent with rapid adsorption kinetics and improved adsorption capacity is critical for treating polluted water. This includes the development of recyclable adsorbents. By doping biochar nanoparticles with interconnected pores on a polyacrylamide hydrogel matrix, the authors have established a one-pot technique to manufacture robust porous nanocomposite hydrogels. The hydrogel nanocomposite, as prepared, was shown to have sufficient mechanical strength to carry the loads while also facilitating the recycling process. Similarly, the incorporated biochar with interconnected pores reduces solvent transport, thereby enhancing adsorption capacity and kinetics. The hydrogel nanocomposite was found to have a stretchability value of 5.9, the tensile strength of 128 kPa, a toughness of 538 J/m2, incessant specific surface area, and an augmented pore volume of 441% and 279%. The study of experimental adsorption isotherms and kinetics, including MB as model adsorbate, revealed the inherent superior adsorption performance of the nanocomposites. The nanocomposite was associated with multiple characteristic properties such as recyclability, strong mechanical robustness, biocompatibility, etc., which further open ample space for the design and development of porous hydrogel nanocomposites for the treatment of wastewater (Wu et al. 2022).
ZnO-TiO2/rGO hybrid nanocomposites were synthesized using a hydrothermal technique and tested for photodegradation and adsorption of an organic dye, MB, in an aqueous media under UV irradiation. FT-IR, UV-Vis, XRD, SEM, TEM, EDXS, Raman spectroscopy, and TGA analyses confirmed the nanocomposites' production. Nanocomposites were discovered to have an average particle diameter of 20 to 30 nm and a specific surface area of 182.52 m2g− 1. Additionally, the existence and homogeneous distribution of ZnO and TiO2 NPs on the rGO surface were experimentally validated. Nanocomposites were found to have 43.68% adsorption efficacy and 99.84% photodegradation ability after 60 mins of exposure at pH = 9, suggesting that the nanocomposites can be further used as a choice able candidate for the treatment of organic dye from wastewater (Bao et al. 2021).
The phase inversion technology was used to construct a carbon nanomaterial-incorporated thin-film nanocomposite (TFN) nanofiltration (NF) membrane incorporating oxidized MWCNT and GO doped over polyethersulfone (PES). Another step involved coating the substrate with polyvinyl alcohol (PVA), then cross-linked with glutaraldehyde (GA) to create a more durable bond. To study the effect of carbon nanomaterial on the nanocomposite, the authors also prepared a thin-film composite (TFC) membrane by avoiding the incorporation of carbon nanomaterial into PES substrate and also obtained the optimal concentrations of GA and PVA solutions. The AFM, contact angle,FT-IR, and SEM were used to describe the TFN (TFN/GO) and TFC (TFN/O-MWCNTs)nanocomposites that were generated in this study. As a result of GO and O-MWCNTs in the PES substrate, the formation of more stretched finger-like holes with more enormous macro voids in the substrate was observed, and a reduction in the depth of the thin skin layer with increased roughness of the surface membrane. In pure water, the TFC membrane had a flow value of 13.2 LMH and a Na2SO4 rejection rate of 84 percent when operated at its optimal pressure of 4 bar. However, TFN/O-MWCNTs demonstrated a 54 percent increase in water permeability, whereas TFN/GO demonstrated a 35 percent increase in water permeability without Na2SO4. The produced nanocomposite showed the maximum rejection efficiency against Na2SO4, MgSO4, and NaCl, indicating that the substrate surface membranes were negatively charged surfaces (Behdarvand, et al. 2021).
Photocatalytic hydrocarbon polymer doped TiO2 nanoparticle-based nanocomposite coatings were developed at room temperature and atmospheric pressure via an aerosol-assisted plasma process. The as-prepared nanocomposites were fabricated on both flat glass slides and open-cell polyurethane foams. The plasma approach allowed for precise control of the deposition of nanocomposites on a variety of complex 3D-porous material structures, which were then subjected to a series of characterization procedures, with a particular emphasis on foams, before being examined. The nanocomposites were evaluated for their photocatalytic ability upon the degradation of the MB, an organic dye, in an aqueous medium under UV irradiation with the aid of the recirculating batch photoreactor. Experiments revealed that open-cell foams could achieve the outstanding photocatalytic activity, highlighting the advantages of macroporous photocatalyst support over traditional flat support. Furthermore, the photocatalytic materials developed showed high reusability and performance maintenance after 40 hours of continuous operation, equivalent to twenty reaction runs. The plasma-coated materials' higher photocatalytic performance and reusability suggested that they could be used for photocatalytic wastewater treatment (Uricchio et al. 2021).
SnO2-GO/PVDF (polyvinylidene fluoride) membranes with entire sponge-like pores were generated through delay phase conversion protocol by introducing SnO2-GO nanocomposites into the solution of polyvinylidene fluoride. The presence of SnO2 and GO interconnections in the SnO2-GO nanocomposites improved the photocatalytic ability by the degradation of the organic dyes and possess trustable modified membranes, which can have the efficiency of self-cleaning (enabled 96.1% recovery). The membrane was 60–80% higher photodegradation efficiency and had excellent photodegradation kinetics toward bovine serum albumin (BSA) over membranes containing GO and SnO2, respectively. High hydrophilicity, sponge-pore-like morphology and greater photodegradation ability were considered the captivating characteristics associated with the developed nanocomposites. Nanomembranes possess 97.2% rejection rate towards BSA under 363.2 L/m2 hi flux values. These results revealed that the membrane can act as a multifunctional antipollution membrane for water treatment in the coming future (Chen et al. 2021).
A facile and cost-effective approach for the development of hybrid magnetic porous Gd2O3-doped GO (GGO) based nanocomposite for the remediation of Pb(II) and Cr(III) contaminated water was established. The developed nanocomposites' morphology and structure were analyzed through different spectral analysis, such as XRD, FTIR, SEM, TEM, XPS, and magnetic measurements. Nanocomposites were found to have a large surface area as compared to native GO and iron oxide-doped GO. The absorption ability of the nanocomposites was found to be enhanced by the presence of surface-active functional groups. There were specific reaction parameters such as pH, the dosage of adsorbent, concentration of the metal ion, and the rate-limiting kinetics on homogeneous surfaces, which were found to influence the performance of GGO significantly. The adsorption ability of GO towards Cr(III) (17.97 mg/g) and Pb(II) (83.04 mg/g) was considerably enhanced by the doping of Gd2O3 on its surface at pH 4.0, 298 K,, 0.5 g/L GGO, and 180 min. Nanocomposites were found to possess 95% Cr(III) and 70% Pb(II) effluent tendency and can be reused up to 3 cycles. Thus, the developed GGO nanocomposites can serve as a valuable candidate for the rejection of anions and cations, including industrial effluents from groundwater and wastewater (Lee et al. 2021).
Using a single alkoxide precursor as a starting material allowed for the production of highly protective TiO2 fused carbon core-based hybrid nanocomposites in a way that was both efficient and effective. Because of its high abundance, low toxicity, and outstanding stability, the nanocomposite that was created is a highly regarded candidate for the photocatalytic treatment of wastewater. In any case, dispersed TiO2 fused carbon core-based hybrid nanocomposites were produced by the partial hydrolysis of titanium alkoxide, which was then followed by subsequent calcinations in an inert atmosphere. This allowed for the fabrication and dispersion of TiO2 particles over the SP2-hybridized carbon, which was discovered to be bonded with the terminal O-atoms.
The as-prepared nanocomposite could be employed to rapidly degrade a large variety of waterborne pollutants such as dyes, pathogens, and pharmaceuticals, even at low concentrations. The incorporation of C inside the nanocomposite significantly improved the absorption of visible light and ultimately led to the separation of photogenerated charge carriers (Chauhan et al. 2020).
A novel and innovative + vely charged thin film nanocomposite (TFN) membrane supported by f-MWCNs of GO was constructed for wastewater treatment by assembling HPEI (hyperbranched polyethyleneimine) followed by the cross-linking of GA (glutaraldehyde) on PAN (polyacrylonitrile). The authors had cross-checked the effect of different reaction parameters, including the concentration of HPEI, pH, and deposition time, on the performance (TFC thin film composite) membrane. The presence of CNs as supporting material leads to the formation of finger-like structures of TFN composite membranes, as confirmed by SEM images. In addition to this, incorporating the effect off-MWCNs or GO upon salt rejection and membrane water permeability was also examined. Experimental results revealed that the nanocomposite membrane composed up of TFN-CNT and TFN-GO showed a high rate of water permeability of 38% and 64%, respectively, due to more hydrophilicity, smoother, finger-like geometry of the supporting layer, and tube-shaped geometry of CNTs or interconnected nanochannels present between adjacent GO nanosheets over TFC membrane. Because the presence of negatively charged materials on the surface of the TFN membranes caused more reactions between the –NH2 and –COOH group of HPEI and PAN, hence, ultimately leading to the formation of a more + vely charged selective layer, as well as the salt rejection tendency, was improved through both Donnan and satiric effect. The rejection potential of MgCl2 was higher towards both TFN membranes and TFC, followed by MgSO4, NaCl, and Na2SO4, and thus confirmed that the surface of the composite membrane was positively charged (Valamohammadi et al. 2020).
BC-GO doped Fe3O4 based nanocomposites were constructed for water treatment by incorporating Fe3O4 NPs in cellulosic black cumin seed powder, followed by subsequent functionalization by GO involving GO co-precipitation methodology XRD confirmed the amphoras natures of the nanocomposites with particle sizes of 95.10 nm. TEM confirmed that nanotubes with a particle size of 30–42 nm were trapped in the carbon frameworks of GO and black cumin seeds. The magnetic potential, good thermal stability, and a large number of –OH and –CO functional on the surface of the produced nanocomposites were disclosed by spectroscopic, thermal, and microscopic techniques. Nanocomposites were also tested in vitro for antibacterial and antioxidant activity, indicating that the nanocomposites have superior antibacterial and antioxidant activity against both G + and G- bacterial strains. Synthesized bioactive nanocomposites were found to be highly safe and beneficial. Thus, they could be applied for the adsorptive removal of different cationic and anionic water pollutants such as methylene blue and arsenic from an aqueous medium. The adsorption data of different organic and inorganic pollutants were well fitted with Freundlich isotherm and followed 2nd order kinetics. At optimal reaction conditions, the nanocomposites had Langmuir activity of 10.0 mg/g and 1.0 mg/g towards methylene blue and arsenic (dose of adsorbent: 1.0g/L for both MB and Ar, initial conc.:10.0 and 1.0 mg/L and pH: 7.0). Thus, the developed nanocomposite can further be used for adsorptive removal of MB and Ar from contaminated water by controlling the growth of bacteria and acting as antioxidants (Tara et al. 2020).
Nanocomposites of TiO2/Ag/MoS2/Ag were developed for water purification by degrading organic pollutants and reducing heavy metal ions. The obtained nanocomposites showed greater photodegradation ability towards RhB and photochemically reduced Cr(II) present in the wastewater at pH = 3. Remarkably, the photocatalytic ability of the nanocomposites was found to be enhanced significantly by the application of 0.003M AgNO3 of Ag NPs on the TiO2 nanobelts, 50% mass fraction of MoS2, 3mL of Tollen's reagent loaded Ag NPs up on MoS2. Mainly, three crucial aspects increase the photocatalytic activity, i.e., formation of TiO2/MoS2 heterojunction, decreased interfacial resistance between MoS2 and TiO2, and LPSR effect of Ag NPs on MoS2 nanosheets. These aspects reduced the recombination rate of holes and electrons and broadened the light response range of TiO2 to the visible region. Therefore, the preparation of 0D, 1D, and 3D nanocomposite structures was highly charming and can also work as a novel photocatalyst for photocatalytic wastewater purification (Jiang et al. 2020).
Treatment of dye contaminated water is now a global thematic issue because of the defects originating due to the presence of toxic chemicals and heavy metal ions in the water system, which affects the marine organisms or other aquatic animals present in the aquatic ecosystem as well as ultimately affects the lives of human beings. Therefore, to gain control over it, Mohamed I. Said 2020 reported the synthesis of mono-based carbon nanocomposites as a novel photocatalyst or adsorbent for treating various cationic anionic dyes following a new and easy precursor-assisted approach. Initially, Mn malonates were synthesized as the starting precursor and calcined for about one h under Ar, H2, and air atmosphere at 350oC. The atmosphere profoundly influenced the synthesis and phase purity of nanocomposites. Perfect MnO nanoparticles were obtained under H2 and Ar atmosphere. Nanocomposites synthesized under H2 were found to have a double surface area over prepared samples under air. Sphere-like geometry with the high crystalline morphology of the prepared nanocomposites was confirmed through HRTEM, SEM, and SAED studies. The presence of carbon in the prepared samples was proved through EDX analysis. Moreover, the existence of mesoporous and microporous pores on the surface of the nanocomposites was detected by Va-t plots and the BJB method. The as-prepared nanocomposites were found to have a surface area of 22.7 and 50.1 m2/g. Nanocomposites prepared under an H2 atmosphere were found to possess 97% of methylene blue (MB) dye removal or adsorption efficacy in 6 h. Also, it could be used as an effective photocatalyst for removing eosin Y, an anionic dye present in water, which was accomplished after two h of exposure to sunlight. The prepared nanocomposites showed good recyclability and preservation in their structure even after four cycling experiments (Said et al. 2020 ).
Cobalt hexaferrite (CoFe12O19) based nanocomposites were synthesized using pigments and carbohydrates as natural and non-toxic reducing agents following a simple, low cost, convenient and eco-friendly sol-gel process. Particle size, morphology, and the purity of the NPs were found to be influenced by various reaction parameters such as concentration of reducing agent, type of reducing agent, temperature and time of calculations, etc. in addition to this, carbon-based nanocomposites were prepared, including CNT and grapheme and the various properties of it were compared with that of pure NPs. The synthesized materials were analyzed by XRD, FE-SEM, TEM, CV, XPS, EDS, DRS, and VSM. The bandgap study predicted by DRS investigated the photocatalytic ability of the nanocomposites. The effect of nanocomposites on the photocatalytic degradation of MO was also evaluated under UV irradiation. The graphene-based nanocomposite was found to have the highest photocatalytic potential, followed by CNT-based nanocomposite and pure nanoparticles. In view of the rate of photocatalytic activity, Pure NPs and CNT-based nanocomposites were found to follow pseudo-first-order kinetics, whereas graphene-based nanocomposites were found to follow zero-order kinetics. The exclusive morphology, geometry, and properties of graphene ultimately lead to better physical adsorption of organic pollutants (MO) on the graphene's surface, thereby enhancing the performance of graphene-based nanocomposites (Ansari et al. 2019).
TiO2-based MoO3-based nanocomposites were synthesized and fabricated hydrothermally using TiCl4 and (NH4)6Mo7O24.4H2O as the Ti and Mo source, respectively, at 180oC. The formation of the nanocrystalline surface of the TiO2 and MoO3 nanocomposites was confirmed by the XRD study. Increasing the amount of Ti-doping amount leads to the smaller size of MoO3 particles, as depicted by TEM. Also, the NPs were found to have a standard particle size of 10 nm. The as-synthesized nanocomposites were found to exhibit the advanced adsorption ability of 180 mg/g, 290 mg/g, and 59 mg/g towards MB, RhB (Rhodamine B), and Cr (VI) of heavy metal ions, respectively (Zhao et al. 2018).
Magnetic cobalt ferrite (CoFe2O4) based nanocomposites containing Cu/Al layered double hydroxide (LDH) particles and CoFe2O4/LDO composites as their calcined equivalent were prepared, characterized, and evaluated for their recoverable efficacy towards methyl orange (MO) dye. The magnetic potentiality of the nanocomposites was found to be dependent upon the relative concentration of CoFe2O4 with respect to LDH, which enabled their quick separation under magnetic influences. The adsorption of MO by both LDH and LDO particles was found to be influenced strongly by the presence of CoFe2O4. The highest monolayered absorption values for pure LDH and LDO were 151 and 807 mg/g. Decreasing the concentration of CoFe2O4 leads to an increase in the MO adsorption capacity to 262 mg/g for LDH and 1355 mg/g for LDO. However, the adsorption capacitance decreased by increasing the concentration of CoFe2O4. The high absorption of the nanocomposites was found to be resulted due to the disrupted interaction between the magnetic NPs and the platelets. Because of their dual behavior of the high tendency of anionic dye adsorption and strong magnetic behavior, the nanocomposites are a value-added material for wastewater remediation (Palza et al. 2019).
Nanocomposites of polypyrrole and Prussian red were synthesized as novel precursors for water treatment using standard protocols and were characterized through FT-IR, TEM, XRD, SEM, etc. The prepared doped nanocomposites exhibited excellent electrical, mechanical, and thermal conductivities over pure NCs. The nanocomposites were found to have the magnetic phase transition ability from paramagnetic to ferromagnetic with respect to a decrease in temperature and also exhibited excellent photocatalytic ability towards antibiotic and dye degradation. The nanocomposites were found to have a more than 80% dye degradation ability towards MO, MB, RhB dyes at room temperature in 80 mins at neutral pH and found to follow the pseudo-first-order rate kinetics. It also possessed good photocatalytic performance towards antibiotics, including levofloxacin, rifampin, and amoxicillin as well as selective adsorption efficacy towards the recovery of costly metal ions of Ag(I), Au(III), and Pt(IV) in the wastewater (Rizvi et al. 2019) management of each microbial and nanoparticles assembling in each smart technology on large scale potential developments in the integration of aforementioned nanotechnology with biological methods.