Here, we report the fabrication of nZVI by the wet chemical technique in the presence of ethanol using ferric iron and sodium borohydride as the reducing agents under ambient conditions. The obtained nZVI particles are mainly in a zero-valent oxidation state and do not undergo significant oxidation for several weeks. The structural and morphological parameters of nZVI were investigated by using UV, XRD, SEM, EDX, TEM, and DLS analysis. The optical nature, bandgap energy, and absorption edge were all revealed by the UV–visible spectrum. The phase development and crystallinity of nZVI particles were shown by the XRD pattern. The morphological investigation revealed that the nanoparticles were spherical with an average size of 34–110 nm by using ImageJ software, and the elemental analysis was analyzed using EDX. Furthermore, the catalytic treatment performance of domestic wastewater was evaluated in terms of pH, COD (chemical oxygen demand) solubilization, total solids (TS), volatile solids (VS), phosphorous, and total nitrogen (TN) reduction under aerobic and anaerobic operating conditions. The effluent was subjected to a process evaluation with a different range (100–500 mg/L) of nZVI dosages. The COD solubilization and suspended solids reduction were significantly improved in the anaerobic condition in comparison to the aerobic condition. Furthermore, the effect of nZVI on phosphorous (PO43−) reduction was enhanced by the electrons of iron ions. The high concentration of nZVI dosing has a positive impact on COD solubilization and phosphorous removal regardless of the aeration condition with 400 mg/L of nZVI dosage.

Molecularly imprinted (MI) magnetic submicroparticles with iron oxide core and silica shell were used as substrate for immobilization of different functions. The activity toward heavy metals was provided via attachment of ethylene diamine tetra acetate (EDTA) silica coated magnetite nanomaterials; then their use in the immobilization of MI magnetite (Fe3O4/SiO2/Thermosensitive/EDTA-CS) nanomaterials to the silica surface with subsequent chemical grafting of EDTA on which coupling occurred via an chitosan bonding. MI of manmade polymeric materials (Fe3O4/SiO2/Thermosensitive/EDTA nanomaterials) are functionalized by the cross-linking of monomeric molecules as an analyte, which react as a molecular template (Self-assembly process). Covalent binding of CS to the magnetite surface proceeds using a free −CH2OH group of CS and a NH2-group of magnetite with EDTA as a cross-linker. This perspective has been originated by Wulff and his subordinates. MI magnetite (Fe3O4/SiO2/Thermosensitive/EDTA-CS) nanomaterials were characterized by X-ray diffraction spectrometry, scanning electron microscopy, energy dispersive X-ray spectroscopy, Fourier transform-infrared spectroscopy, vibrating sample magnetometry, and dynamic light scattering. The prepared MI magnetite nanomaterials (Fe3O4/SiO2/Thermosensitive/EDTA-CS) were used as corrosion inhibitors.Download : Download full-size imageFigure A. Mechanism of MI magnetite nanomaterials (Fe3O4@SiO2) with Trinitrotoluene (TNT) (Ahmad et al., 2018). Reproduced with permission from Ahmad, I., Siddiqui, W.A., Qadir, S., & Ahmad, T. (2018). Synthesis and characterization of molecular imprinted nanomaterials for the removal of heavy metals from water. Journal of Materials Research and Technology, 7(3), 270–282. Copyright 2021 @ Elsevier. Figure A. Mechanism of MI magnetite nanomaterials (Fe3O4@SiO2) with Trinitrotoluene (TNT) (Ahmad et al., 2018). Reproduced with permission from Ahmad, I., Siddiqui, W.A., Qadir, S., & Ahmad, T. (2018). Synthesis and characterization of molecular imprinted nanomaterials for the removal of heavy metals from water. Journal of Materials Research and Technology, 7(3), 270–282. Copyright 2021 @ Elsevier.

Here, we present an innovative and creative sustainable technique for the fabrication of titania (TiO2) using Acorus calamus (A. calamus) leaf extract as a new biogenic source, as well as a capping and reducing agent. The optical, structural, morphological, surface, and thermal characteristics of biosynthesized nanoparticles were investigated using UV, FTIR, SEM, DLS, BET, and TGA-DSC analysis. The phase formation and presence of nanocrystalline TiO2 were revealed by the XRD pattern. FTIR analysis revealed conjugation, as well as the presence of Ti–O and O–H vibrational bands. The nanoparticles were noticed to be globular, with an average size of 15–40 nm, according to the morphological analysis, and the impact of size quantification was also investigated using DLS. The photocatalytic activity of bare, commercial P-25 and biosynthesized TiO2 (G-TiO2) nanoparticles in aqueous solution of rhodamine B (RhB) dye was investigated under visible light irradiation at different time intervals. The biosynthesized TiO2 nanoparticles exhibited strong photocatalytic activity, degrading 96.59% of the RhB dye. Different kinetic representations were utilized to analyze equilibrium details. The pseudo-first-order reaction was best suited with equilibrium rate constant (K1) and regression coefficients (R2) values 3.72 × 10−4 and 0.99, respectively. The antimicrobial efficacy of the prepared nanoparticles was investigated using the disc diffusion technique. Further, biosynthesized TiO2 showed excellent antimicrobial activity against the selected gram-positive staining (B. subtilis, S. aureus) over gram-negative (P. aeruginosa, E. coli) pathogenic bacteria in comparison to bare TiO2.

This paper studies a new response surface methodology (RSM) based on the central composite design (CCD) modeling method to optimize the photocatalytic degradation of methylene blue (MB) and methyl orange (MO) by using a synthesized ZnO/Alg bionanocomposite under UV irradiation. ZnO with different content of sodium alginate (Alg) (10, 20, and 30% by weight) has been synthesized by a one-step sol-gel method. Zinc oxide (ZnO) nanoparticles were impregnated on the alginate polymer. Various characterization techniques were used to describe the physical and chemical properties of each catalyst such as XRD, FTIR, UV-vis, PL, FESEM, Raman, and BET. The optimal catalyst for MB and MO photocatalytic degradation process was discussed mathematically as a function of catalyst dose, irradiation time, and MB and MO concentration, which was modeled by CCD-RSM based on a statistical model (quadratic regression) and an optimization process (ANOVA analysis). The photocatalytic degradation efficiency of 98% was achieved for the optimal conditions of a dye concentration of 20 mg L-1, the catalyst dose of 0.34 g L-1, and an irradiation time of 90 min at pH 6. The measurement result (R 2 = 0.9901) showed that the considered model is very suitable, and the selected CCD-RSM successfully optimized the photodegradation conditions of MB and MO.

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In this study, we aimed to observe how different operating parameters influenced the photocatalytic degradation of rhodamine B (RhB, cationic dye) and bromophenol Blue (BPB, anionic dye) over ZnO/CuO under visible light irradiation. This further corroborated the optimization study employing the response surface methodology (RSM) based on central composite design (CCD). The synthesis of the ZnO/CuO nanocomposite was carried out using the co-precipitation method. The synthesized samples were characterized via the XRD, FT-IR, FE-SEM, Raman, and BET techniques. The characterization revealed that the nanostructured ZnO/CuO formulation showed the highest surface area (83.13 m2·g−1). Its surface area was much higher than that of pure ZnO and CuO, thereby inheriting the highest photocatalytic activity. To substantiate this photocatalytic action, the investigative analysis was carried out at room temperature, associating first-order kinetics at a rate constant of 0.0464 min−1 for BPB and 0.07091 min−1 for RhB. We examined and assessed the binary interactions of the catalyst dosage, concentration of dye, and irradiation time. The suggested equation, with a high regression R2 value of 0.99701 for BPB and 0.9977 for RhB, accurately matched the experimental results. Through ANOVA we found that the most relevant individual parameter was the irradiation time, followed by catalyst dose and dye concentration. In a validation experiment, RSM based on CCD was found to be suitable for the optimization of the photocatalytic degradation of BPB and RhB over ZnO/CuO photocatalysts, with 98% degradation efficiency.

Concrete is the commonly used building material and has a high tendency to develop cracks. Due to these crack formations, concrete service life and high replacement cost declined significantly. Although different types of methods are available to heal the cracks, it is impossible to stop crack formation. It has been observed that some existing concrete healing methods, such as chemicals and polymers, are the sources of the environmental health risks and effective only for a short time period. Therefore eco-friendly and prolonged treatment methods are in high demand. Self-healing method of concrete with a microbe is eco-friendly as well as has an ability to repair prolonged, fast, and active cracks. This research presents a summary of the microbial procedures to improve the self-healing capacity for active and independent cracks. In this overview, zeolite-immobilized bacteria have been used as a carrier material, which is generally present in the concrete to protect bacteria in an increased pH environment. The activity of zeolite bacteria has been explored with a view to study the prospects of generating healing compounds. The self-healing capacity of the normal and fibre-reinforced zeolite-immobilized mortar has been decided on the basis of the confining strength and the development of permeable properties of the time period of cracked specimen’s with morphological characterization of crack healing compounds by using X-ray diffraction, energy dispersion spectrometer and scanning electron microscopy.

US Food and Drug Administration (FDA) allowed for direct addition of castor oilfor human consumption as food and most recently FDA approved castor oil as over-the-counter(OTC) for laxative drug. The present article highlights the green route phosphorylation of castor oil (COL) via condensation polymerization. Further, the incorporation of metal ions Cu (II)) and Zn (II) into the polymer matrix have been carried out at elevated temperature using catalyst p-toluene sulphonic acid (PTSA). The modification of the said material has been confirmed by FT-IR, UV–VIS, and 1H and 31P-NMR spectroscopy. Further, the in vitro antibacterial activities of the metal incorporated-COL has been performed by standard methods against B. cereus (MCC2243) (gram-positive) and E. coli (MCC2412) (gram-negative) bacteria. The results revealed that the incorporation of metal ions into the polymer matrix increases the antibacterial activity largely. This may be governed by the electrostatic interaction between metal ions and microbes, also the generation of free active oxygen hinders the normal activity of bacteria. These results suggest that the synthesized material may act a potential candidate for low cost, environment friendly antibacterial agents and may find their application in clinical fields. Herein we are also proposing mechanism of antibacterial activity.

The herbicide 2,4-Dichlorophenoxyacetic acid (2,4-D) affects the environment through its moderate toxicity in water bodies and caused water pollution. The aim of this study is to investigate the degraded amount of traditionally used low-cost herbicide e.g.2,4-D from the water by using kinetic parameters with the help of a cost- effective new photo-catalyst Graphene-Polyindole nanocomposites (Gr-PIn NC). This nanocomposite (NC) synthesized by using the sol-gel technique and characterized by X-ray diffraction (XRD) and Scanning electron microscope (SEM) spectroscopy, which reveals the amorphous character and dispersed form of Polyindole on Graphene layers. Furthermore, Fourier-transform infrared (FTIR)-spectra confirm the vibrations phenomenon in polyindole due to the presence of pi-pi (π-π) interactions of graphene carbon double bonds (C=C) between Graphene layers. The Gr-PIn NC rate constant results exhibited almost 99% promising photodegradation efficiency for 2,4-D herbicide in presence of UV-vis. light irradiation via production of highly reactive oxygen species and, where synthesized nanocomposite shows its efficiency as twice than the pure polyindole polymer.

Metals are widely used in numerous applications since the ancient time from infrastructure to aircraft to consumer products and hold a significant effect in everyday life. It is necessary to protect the metal especially from corrosion and has been an active research area in material science for many years. This chapter discusses self-repairing composite according to its self-repairing mechanism in three categories to hinder the corrosion as capsule-based, vascular-based, and intrinsic self-repairing material. It starts by an overview of the giant problem of corrosion and its preventive steps. It then explains how the self-repairing composite material would be a strong candidate to overcome this corrosion problem by comparing the conventional steps to hinder corrosion. By the end of the chapter the challenges facing to commercialize this technique is discussed. A full discussion of self-repairing composite material works by different examples and the relationship of its applicability with key concept is put together.

Wastewater adversely affects humans and another animal including metal like Pb, As, Zn, Hg, and Cd in wastewater (domestic or industrial). These toxic metals affect human health and are a serious threat to the environment by the precipitation, adsorption, accumulation in the food chain and non-biodegradable nature, respectively. In the present study, treatment of industrial wastewater in terms of toxic Pb(II) removal was investigated by the using of copper oxide alginate (CuO/Alg) nanocomposite. The CuO/Alg nanocomposite was prepared by chemical reduction method in solution phase, and synthesized particles size were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The wastewater sample collected from WWTP of the local electroplating industry is located in Okhla Industrial Area, New Delhi. A series of experimental approaches have been used to remove Pb2+ from industrial wastewater with CuO/Alg nanocomposite, which includes sorbent mass, competitive ion, contact time, and SEM. The SEM image of CuO/Alg nanocomposite showed that particles had a sheet-like shape and mean diameter of about 18.09 nm. The test was performed under the batch condition to determine the adsorption rate and uptake at equilibrium from single component solution. The maximum uptake value of Pb2+ in single component solution was 118.40 mg/g from wastewater. The CuO/Alg nanocomposite identified as the most promising sorbent with an effective potential of removal of Pb2+ from wastewater is due to their high metal uptake.

Nanoporous metal-organic frameworks (MOFs) are three-dimensional porous lattices of inorganic-organic linkers. These materials have tunable physiochemical properties such as high porosity, crystalline nature, chemical, thermal and mechanical stability as well. The fabrication of different MOFs can be approached by synthetic modification methods for instance modulated synthesis and post-synthetic modification. Synthetic modifications develop most stable functionalized MOFs materials, which play the most promising role in different fields such as gas separation, catalysis, gas storage, water treatment, and other different applications.

The high surface area metal organic-frameworks (MOFs) are highly porous structures made of distinct inorganic and organic building blocks, so their chemical and structural multiplicity is vast. While that variety has led to lots of potential applications, including fuel cell, solar cell, supercapacitor, lithium-ion batteries, gas storage and conversion, it also means that finding the optimal MOF for a specific application is hard to reach. This chapter discusses the design approach of MOFs based on clean energy applications in four categories. It starts with an overview of the MOFs approach for the giant problem of clean energy. It then explains how the MOFs material is a strong candidate to overcome this problem by comparing the different design approaches. By the end of the chapter, the challenges facing to commercialize this technique is discussed. [GRAPHICS] .

Nanographene consists of an infinite number of benzene rings with a zero band gap. Fused together, it can be referred to as an infinite polyaromatic hydrocarbon (PAH). It's successfully renewed and isolated while receiving more widespread attention since the first experimental research on graphene in 2004. However, the fabrication of nanographene and nanographene composites includes different types of processes, including nonconventional approaches, structural, selective heteroatom doping, and direct edge functionalization by the incorporation of some functional groups. The modification of graphene to graphene nanocomposites or nanoparticle sheets has extensively increased its applications in water purification. Recently, graphene nanocomposites have shown very capable application in various types of water purification. This chapter highlights the most recent fabrications, properties, and applications of graphene and graphene nanocomposites for water desalination, sorption, catalytic activity, reverse osmosis, nanofiltration, chlorine sensors, and remediation of radionuclide and heavy metal agents in complete water purification systems. Here, we primarily focus on nanographene composites as an ion exchanger in different types of water purification as well as the removal of toxic organic, inorganic (cationic and anionic), and mixed pollutants and the use of catalytic oxidation degradation of toxic contaminants. Furthermore, we discuss the removal of salts and other small molecules such as radionuclide agents from wastewater by the use of reverse osmosis, nanofiltration, and chlorine sensors as a traditional adsorbent/ion exchanger. We have also discussed the properties of nanographene composite ion exchangers.

The effects of annealing on copper (II) oxide/sodium alginate (CuO/Alg) bionanocomposite synthesized via simple sol-gel method are investigated by using x-ray diffraction technique, scanning electron microscopy (SEM) and transmission electron microscopy (TEM), UV–visible spectroscopy and dielectric measurements. In order to understand the role of growth conditions on the resultant composite material, we found that the most substantial changes in structure from rod-like hexagonal shape to sheet-like structure and in electrical and optical properties occurred at a temperature higher than 400 °C. The results of dielectric measurement indicate that the parameters ε′, ε″, tan δ and σac are decreasing with the increase in frequency; whereas these parameters increase with the increase in temperature. It was also observed that the size of nanoparticles is varying at different concentration of sodium alginate. So, the CuO/Alg bionanocomposite is better dielectric material with high optical band gap value, lower dielectric loss than pristine CuO nanoparticles and could be a better alternative in various fields of electronic applications like in rechargeable batteries, supercapacitor as well as semiconductor devices and in sensors also.

Water pollution is one of the most severe problems in the world, which puts the survival and development of human society at risk. Therefore, developing efficient and cost-effective technologies for the removal of water pollutants has become a hot topic. In this chapter, we deal with the different methods of preparation of metal-organic frameworks (MOFs) and their application in wastewater treatment. The modular structure with a wide variety of MOFs with different active metal sites and organic linkers must prove to be ideal adsorbents or photocatalysts for water purification. In this chapter, current approaches in the extraction and degradation of water pollutants by MOFs are highlighted.

US Food and Drug Administration (FDA) permitted for direct addition of castor oil into food for human consumption and recently FDA approved castor oil as over-the-counter (OTC) for laxative drug. Castor oil (COL) is a vegetable oil and naturally polyol which is inexpensive, environmental friendly and a very valuable renewable resource. Metals are believed to influence antioxidant property of ligands. Metals copper, zinc, cobalt and barium were incorporated with castor oil and subsequently structures were established by FT-IR, UV-Visible, and H-1 NMR spectroscopic techniques. In vitro antioxidant activities of metal containing COL were determined by DPPH and superoxide scavenging methods and the results were compared with vitamin C. Enhanced antioxidant nature of metal containing castor oil was noticed and compared to virgin castor oil. This study reveals that synthesized metal containing-COL is a potential antioxidant material.

CuO@Alginate (CuO@Alg) nanocomposite has been synthesized by simple, inexpensive and highly efficient Sol-Gel method. The morphology and structural properties of synthesized nanocomposite (CuO@Alg) and pure CuO nanoparticles have been analyzed as a function of temperature. The morphological and structural properties were investigated by using TEM, SEM, EDX, and X-ray diffraction. The crystalline nature of CuO nanocomposite showed by X-ray diffraction (XRD) pattern and average crystalline size was observed approximately 18.09 nm. The effect of size quantization on morphology was also observed. Dielectric behavior of CuO and CuO@Alg has been also studied as a function of increasing frequency by LCR meter. With the increase in frequency, the dielectric constant was found to decrease and alternative current (A.C.) conductivity value was found to increase. This study was also representing a useful step towards the establishment of a structure–property relationship for CuO nanocomposite.

A liquefaction process to convert waste plastic into fuel oil was studied over three commercial catalysts namely zeolite Y, Silica Alumina (SA) and fluid catalytic cracking (FCC) catalyst. A catalytic cracking process in which waste plastic were melted and cracked into smaller molecular weight hydrocarbons and at very high temperature, the resulting gas was cooled by condensation and resulting fuel oil was recovered. More specifically the effect of different catalysts on liquid yield was studied. The degradation of waste plastic especially high-density polyethylene was studied in a semi-batch reactor. The best results were obtained when FCC catalyst was used.