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Based on the versatile nature and applications of Carbon foam (CF), up to now many attempts were performed to improve the structure and properties of CF by incorporating various additives in the CF matrix. But these additives improved one property on the cost of another ones. Herein, we have synergistically incorporated multi-walled carbon nanotubes (MWCNTs) and graphene oxide (GO) with varying loadings as additives in the CF matrix via direct pyrolysis to achieve all the desired properties. Seven different types of CF composites including pure CF were prepared and their effect on the structure, mechanical, thermal, electrical and catalytic characteristics has been reported. The results revealed that after the inclusion of MWCNTs and GO contents, the microstructural performance of CF samples was amazingly improved. Additionally, it was observed that mechanical, thermal, electrical and catalytic behaviors of the CF samples were significantly enhances by the increase of nanohybrids. The compressive strength and Young's modulus reveals their optimum limits up to 19.3 and 57.4 MPa respectively on 2 wt.% MWCNTs-GO additive loadings. Similarly, the greatest thermal and electrical conductivities of 30.92 W/m. K and 27.4 × 103 S/m were showed by CF samples having 2 wt. % MWCNTs-GO loadings. Whereas, the decolorization activity of the CF and their nanocomposites were tested against methyl orange dye and it was observed that the sample with enhanced MWCNTs and GO have good decolorization activity and much sustainable than other samples. The 4% CF/MWCNTs-GO decolorized about 76% MO dye under exposure to UV light within 60 min. The decolorization of MO dye increases with increasing nanocomposite dosage and decreasing initial dye concentration.

Iron oxide nanoparticles (Fe3O4NPs) and iron–indium oxide nanocomposite (Fe3O4-In2O3NC) were prepared through chemical reduction approach and utilized for the photodegradation of methylene blue (MB) dye in aqueous solution. The as-synthesized materials were characterized by scanning electron microscopy (SEM), thermo-gravimetric analysis (TGA), energy-dispersive X-rays (EDX) as well as Fourier transform infrared (FT-IR). SEM studies showed that NPs were present both in discrete and in agglomerated form having round shape and size below 100 nm. FTIR analysis also confirms synthesis of oxide nanoparticles. Fe3O4NPs and Fe3O4-In2O3NC are employed as photocatalysts for photodegradation of MB, and about 88 ± 1 and 97 ± 1% dye was photodegraded in 6 h under UV light, respectively. Recovered Fe3O4and Fe3O4-In2O3nanoparticles significantly photodegraded MB dye. The effect of important parameters such as effect of pH, H2O2, catalyst dosage and initial dye concentration on dye degradation was studied. Degradation study was also carried out under visible light; obtained result indicated that photodegradation ability of Fe3O4-In2O3NC is less in visible light (60 ± 1% dye degradation in 6 h) than the degradation under UV light. Promising bioactivities were demonstrated by Fe3O4-In2O3NC against two pathogenic bacteria Proteus mirabilisand Acinetobacter baumannii. Fe3O4-In2O3NC exhibited excellent antioxidant activity (87 ± 1%) almost comparable to the standard ascorbic acid (90 ± 1%).

The functionalized multi-walled carbon nanotubes (F-MWCNTs) filled polyethylene oxide (PEO) nanocomposites were prepared by casting technique and characterized by scanning electron microscopy (SEM), polarized optical microscopy (POM), thermal gravimetric analysis (TGA) and differential thermal analysis (DTA). The MWCNTs were functionalized by Friedel–Crafts acylation, which introduced aromatic amine groups on the side wall of nanotubes. The SEM micrograph of F-MWCNTs/PEO nanocomposites fractured surfaces indicated that the F-MWCNTs were well dispersed within the PEO matrix. The POM study presented that the neat PEO upon crystallization showed considerable size of crystalline spherulites. The sizes of spherulites decreased with incorporation of F-MWCNTs into the polymer matrix, which might be due to the nucleation role of F-MWCNTs in F-MWCNTs/PEO composite. The DSC analysis showed that the Tmof pure PEO was about 66 °C, which slightly decreased by the incorporation of F-MWCNTs into the polymer matrix. The Tmof 1, 3 and 5 wt% F-MWCNTs/PEO nanocomposites was 65.6, 64 and 63.8 °C, respectively. It was also observed that the thermal stabilities of pure PEO were shifted towards higher temperature when F-MWCNTs were incorporated into the polymer matrix. The TGA analysis represents that pure PEO and 1 wt% of F-MWCNTs/PEO nanocomposite decomposed completely at about 460 °C while thermal stability of 3 and 5 wt% of F-MWCNTs/PEO nanocomposites were shifted towards higher temperature.

2,4,6-trinitrophenol (TNP) has various industrial applications and is also extremely used by militaries and terrorists to make various explosives. Owing to their extensive industrial and military use and higher water solubility, their huge quantity is released into the environment and thus become a momentous environmental pollutant. TNP is highly toxic, poorly biodegradable, and a vigorous poison, strongly carcinogenic, and could cause severe diseases in humans and other animals. Thus, TNP present in the industrial wastewater and landfill leachate must be removed due to its detrimental effects on natural ecosystems. In the present review, the nature of TNP and its decontamination approaches are discussed, as well as their detailed mechanisms. The challenges that arise while applying TNP decontamination approaches were discussed and some future directions are highlighted for enhancing the efficiency of these approaches in a sustainable and friendly manner.

Zirconia-supported palladium (Pd/ZrO2) and Zirconia-supported platinum (Pt/ZrO2) nanoparticles (NPs) are synthesized from their precursors via impregnation technique. The Pd/ZrO2and Pt/ZrO2NPs were analyzed via SEM and EDX, while the study of indigo disulfonate dye degradation was carried out by UV/VIS spectrophotometer. The SEM micrographs illustrated that the Pd and Pt NPs were well placed on ZrO2surface. The Pd/ZrO2and Pt/ZrO2NPs were also employed as photocatalysts for the photodegradation of indigo disulfonate in an aqueous medium under UV-light irradiation. The photodegradation study presented that Pd/ZrO2and Pt/ZrO2NPs degraded 96 and 94% of indigo disulfonate in 14 h, respectively. The effect of pH of medium and catalyst dosage and efficiency of recovered Pd/ZrO2and Pt/ZrO2NPs on the photocatalytic degradation were also studied. It was also found that the maximum degradation of dye was found at pH 10 (95–97%) and at 0.02 g weight (40.28%).

Multiwalled carbon nanotubes (MWCNTs) supported and unsupported bimetallic iron and manganese oxides nanoparticles (Fe-Mn NPs) were synthesized by wet chemical precipitation method. The synthesized nanoparticles were then characterized by various instrumental techniques such as scanning electron microscopy (SEM), energy dispersive X-ray and X-ray diffraction. The MWCNTs/Fe-Mn and Fe-Mn NPs were used as photocatalysts for the photodegradation of methylene blue in aqueous medium. The photodegradation study was monitored by using UV–Vis spectrophotometer. The effect of various parameters such as irradiation time, pH, catalyst dosage and concentration of dye on the photocatalytic degradation was studied. The activity of recovered catalyst was also examined.

Titanium oxide supported palladium (TiO2/Pd) and titanium oxide supported platinum (TiO2/Pt) nanoparticles were prepared from their precursors through the incipient wetness method. The TiO2/Pd and TiO2/Pt nanoparticles were characterized by scanning electron microscopy (SEM), and energy dispersive X-rays (EDX), while the photodegradation study of methyl violet was performed by UV/VIS spectrophotometry. The morphological study shows that the Pd and Pt were well deposited on the surface of TiO2, which was confirmed by EDX. Both TiO2/Pd and TiO2/Pt nanoparticles were used as photocatalysts for the photodegradation of methyl violet in aqueous media under UV-light irradiation. The photodegradation study revealed that the TiO2/Pd and TiO2/Pt nanoparticles degraded about 95 and 78% of dye within 20 min, respectively. The effect of various parameters such as catalyst dosage, concentration of dye, and medium on the photocatalytic degradation was examined. The activity of recovered TiO2/Pd and TiO2/Pt nanoparticles was studied.

AbstractPolyacrylonitrile (PAN) nanofibers were prepared by an electrospinning technique. PAN nanofibers were chemically modified with amidoxime groups. The titanium oxide (TiO2) was then introduced to amidoxime-modified PAN (OM-PAN), which was then used for the photodegradation of methylene blue in aqueous solution. The morphology and photodegradation study was investigated by using scanning electron microscopy (SEM) and UV-visible spectrophotometry, respectively. The SEM study showed the presence of TiO2particles on the surface of OM-PAN nanofiber mat in agglomerated form and was confirmed by energy dispersive X-rays analysis. The photodegradation study of methylene blue showed that the dye degradation was increased as increased in the irradiation time. The effect of pH on degradation efficiency showed that with an increase in pH the degradation efficiency increases.

The Nickel oxide nanoparticles (NiO NPs) and Nickel oxide/Nanoclay nanocomposite (NiO/Nc NC) were synthesized by chemical reduction method and used for the photodegradation of Orange II dyes in aqueous solution. The synthesized samples were characterized through SEM, EDX, FTIR and TGA. The SEM analysis presented that the NiO NPs are spherical with irregular shapes and sizes. The size of particles is in the range of 100–400 nm. It was also observed that the NiO NPs are deposited on the surface of Nanoclay. The EDX study confirmed the formation of metal NPs and verify and purity. The FT-IR spectra of NiO and NiO/Nc NC presented peaks at 432 cm−1and 504 cm−1, which correspond to NiO while peak at 1090–940 cm−1is due to Si–O stretching vibration of orthosilicate anions and Si–O–Al groups. The photodegradation study illustrated that the NiO NPs and NiO/Nc NC degraded about 93 and 96% Orange II in aqueous medium, respectively within 20 min. The effect of various parameters like initial concentration of dyes, pH, recycled catalysts, and catalyst dosage were also studied.

Removal of heavy metals and dyes from wastewater has received great attention due to scarcity of clean water worldwide. Herein an approach was introduced to attain this goal by employing a single material. Chitosan films were prepared, cross-linked it and utilized for the adsorption of cobalt from aqueous medium. The cobalt adsorbed chitosan was then reutilized as a photocatalyst for the photodegradation of methyl violet dyes. The prepared chitosan, cross-linked chitosan and cobalt adsorbed cross-linked chitosan were characterized through scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR). SEM and EDX confirmed the adsorption of cobalt on the cross-linked chitosan. TGA analysis proved the increase in thermal stability with cross-linking while FTIR confirmed the cross-linking of chitosan. Maximum cobalt adsorption of 144 mg/g occurs at 600 ppm salt concentration. The photodegradation study shows that the fresh cobalt adsorbed cross-linked chitosan degraded about 97.78% methyl violet dye within 180 min under UV light, while the recovered degraded about 86.97% within the same time. Efficient degradation was observed at low initial dye concentration and at 30 ppm about 92.16% dye degraded.

Nylon 6/6 and ZnO/nylon 6/6 nanocomposite films were prepared by solvent casting method. Morphological study displayed that ZnO NPs are better dispersed in nylon 6/6. However, some agglomerations were found by the incorporation of high quantities of fillers. The thermal stabilities of neat nylon 6/6 films decreased by addition of nanoparticles (NPs). DSC study shows that the NPs slow down the crystallization rate of neat polymer matrix. POM of Nylon 6/6 upon crystallization showed distinct sized spherulites, which decreased by the incorporation of NPs because of nucleation effect of NPs. The mechanical properties of neat polymer are decreased by addition of ZnO NPs, which might be due to agglomeration of fillers. The neat nylon 6/6 and ZnO/nylon 6/6 nanocomposite were used for the photodegradation of alizarin red (AR) dye, which shows that pure nylon 6/6 degraded about 28% dye while 30% ZnO/Nylon 6/6 degraded about 58.3% dye within 5 h irradiation.

Functionalized multiwalled carbon nanotubes (F-MWCNTs)/Co–Ti oxide nanocomposites and neat Co–Ti oxide nanoparticles were synthesized by chemical reduction method. The scanning electron microscopy micrographs show that the bimetallic NPs in F-MWCNTs/Co–Ti are present in dispersed form while the neat Co–Ti nanoparticles were found in agglomerated form. The formation of nanocomposites and neat Co–Ti nanoparticles was also confirmed by energy-dispersive X-ray. Both types of nanocomposites were employed as photocatalyst for the photodegradation of Rhodamine B in aqueous medium under UV light irradiation. The photodegradation study was performed via UV–Vis spectrophotometer. The photodegradation results show that F-MWCNTs/Co–Ti oxide NPs degraded about 93.35% dye within 150 min irradiation time while the neat Co–Ti oxide NPs degraded about 91.76% dye within same irradiation time. The F-MWCNTs/Co–Ti can be easily removed and recycled due to its bulky composite nature as compared to neat Co–Ti oxide NPs. The effect of dye concentration, catalyst dosage, pH of medium and activity of recycled catalyst was also evaluated.

We establish some unique fixed point theorems in complete partial metric spaces for generalized weakly S-contractive mappings, containing two altering distance functions under certain assumptions. Also, we discuss some examples in support of our main results.