Enhanced photocatalytic performance of magnetic multi-walled carbon nanotubes/cerium dioxide nanocomposite

An Updated Overview of Magnetic Composites for Water Decontamination

Water contamination by harmful organic and inorganic compounds seriously burdens human health and aquatic life. A series of conventional water purification methods can be employed, yet they come with certain disadvantages, including resulting sludge or solid waste, incomplete treatment process, and high costs. To overcome these limitations, attention has been drawn to nanotechnology for fabricating better-performing adsorbents for contaminant removal. In particular, magnetic nanostructures hold promise for water decontamination applications, benefiting from easy removal from aqueous solutions. In this respect, numerous researchers worldwide have reported incorporating magnetic particles into many composite materials. Therefore, this review aims to present the newest advancements in the field of magnetic composites for water decontamination, describing the appealing properties of a series of base materials and including the results of the most recent studies. In more detail, carbon-, polymer-, hydrogel-, aerogel-, silica-, clay-, biochar-, metal-organic framework-, and covalent organic framework-based magnetic composites are overviewed, which have displayed promising adsorption capacity for industrial pollutants.

Recent advances in nanomaterials based sustainable approaches for mitigation of emerging organic pollutants

Emerging organic pollutants (EOPs) are a category of pollutants that are relatively new to the environment and recently garnered a lot of attention. The majority of EOPs includes endocrine-disrupting chemicals (EDCs), antibiotic resistance genes (ARGs), pesticides, dyes and pharmaceutical and personal care products (PPCPs). Exposure to contaminated water has been linked to an increase in incidences of malnutrition, intrauterine growth retardation, respiratory illnesses, liver malfunctions, eye and skin diseases, and fatalities. Consequently, there is a critical need for wastewater remediation technologies which are effective, reliable, and economical. Conventional wastewater treatment methods have several shortcomings that can be addressed with the help of nanotechnology. Unique characteristics of nanomaterials (NMs) make them intriguing and efficient alternative in wastewater treatment strategies. This review emphasis on the occurrence of divers emerging organic pollutants (EOPs) in water and their effective elimination via different NMs based methods with in-depth mechanisms. Furthermore, it also delves the toxicity assessment of NMs and critical challenges, which are crucial steps for practical implementations.

Covalent and Non-covalent Functionalized Nanomaterials for Environmental Restoration

Nanotechnology has emerged as an extraordinary and rapidly developing discipline of science. It has remolded the fate of the whole world by providing diverse horizons in different fields. Nanomaterials are appealing because of their incredibly small size and large surface area. Apart from the naturally occurring nanomaterials, synthetic nanomaterials are being prepared on large scales with different sizes and properties. Such nanomaterials are being utilized as an innovative and green approach in multiple fields. To expand the applications and enhance the properties of the nanomaterials, their functionalization and engineering are being performed on a massive scale. The functionalization helps to add to the existing useful properties of the nanomaterials, hence broadening the scope of their utilization. A large class of covalent and non-covalent functionalized nanomaterials (FNMs) including carbons, metal oxides, quantum dots, and composites of these materials with other organic or inorganic materials are being synthesized and used for environmental remediation applications including wastewater treatment. This review summarizes recent advances in the synthesis, reporting techniques, and applications of FNMs in adsorptive and photocatalytic removal of pollutants from wastewater. Future prospects are also examined, along with suggestions for attaining massive benefits in the areas of FNMs.

Magnetic nanocomposites for sustainable water purification-a comprehensive review

Numerous contaminants in huge amounts are discharged to the environment from various anthropogenic activities. Waterbodies are one of the major receivers of these contaminants. The contaminated water can pose serious threats to humans and animals, by distrubing the ecosystem. In treating the contaminated water, adsorption processes have attained significant maturity due to lower cost, easy operation and environmental friendliness. The adsorption process uses various adsorbent materials and some of emerging adsorbent materials include carbon- and polymer-based magnetic nanocomposites. These hybrid magnetic nanocomposites have attained extensive applications in water treatment technologies due to their magnetic properties as well as combination of unique characteristics of organic and inorganic elements. Carbon- and polymer-related magnetic nanocomposites are more adapted materials for the removal of various kinds of contaminants from waterbodies. These nanocomposites can be produced via different approaches such as filling, pulse-laser irradiation, ball milling, and electro-spinning. This comprehensive review is compiled by reviewing published work of last the latest recent 3 years. The review article extensively focuses on different approaches for producing various carbon- and polymer-based magnetic nanocomposites, their merits and demerits and applications for sustainable water purification. More specifically, use of carbon- and polymer-based magnetic nanocomposites for removal of heavy metal ions and dyes is discussed in detail, critically analyzed and compared with other technologies. In addition, commercial viability in terms of regeneration of adsorbents is also reviewed. Furthermore, the future challenges and prospects in employing magnetic nanocomposites for contaminant removal from various water sources are presented.

Facile fabrication and application of poly(ortho-phenetidine) nanocomposite coating for solid-phase microextraction of carcinogenic polycyclic aromatic hydrocarbons from wastewaters

The waters and wastewaters around industrial areas are heavily polluted and have adverse effects on the ecosystems. The present study is mainly focused on the electropolymerization of ortho-phenetidine and co-deposited on a steel wire along with graphene oxide nanosheets as a novel coating for solid-phase microextraction of polycyclic aromatic hydrocarbons (PAHs) from aqueous media prior to gas chromatography-mass spectrometry. PAHs are composed of multiple aromatic rings which have been linked to skin, lung, bladder and liver. Cancer is a primary human health risk of exposure to PAHs. To obtain a firm and stable coating, several empirical factors relevant to the electrochemical process were investigated. Characterization for chemical structure and surface morphology of the synthesized nanocomposite was conducted with FT-IR spectroscopy and FE-SEM, respectively. XRD and TGA were applied to study the other properties of the nanocomposite. Some essential items involved in microextraction process were also checked in details. Under optimized case, validation parameters were assessed. Wide linearity (0.005-5.0 ng mL^-1), low detection limits (0.4-4.3 pg mL^-1) and good repeatability (3.6-9.5%) and reproducibility (7.6-11.8%) were achieved. The developed method was utilized to analyze contaminated real samples such as wastewater samples from coal processing industries and agricultural water samples collected from the vicinity of the industry in different seasons and high recoveries were obtained, finally.

Effect of carbon nanotubes loading on the photocatalytic activity of BiSI/BiOI as a novel photocatalyst

In this paper, a simple hydrothermal method is employed to synthesize BiSI/BiOI/CNT nanocomposite with enhanced photocatalytic activity. The properties of the prepared samples were studied using nitrogen adsorption-desorption isotherm, photoluminescence, X-ray diffraction analysis (XRD), field-emission scanning electron microscopy (FE-SEM), energy dispersive spectrometry (EDS), UV-vis diffuse reflectance spectroscopy (DRS), and electrochemical impedance spectroscopy (EIS). The loading amount of CNT had a significant influence on the photoactivity of the BiSI/BiOI/CNT composite. In this study, several BiSI/BiOI/CNT nanocomposite samples with various mass ratios of CNT were made-up for further investigation to scrutinize the influence of CNT content on the photocatalytic activity of the nanocomposite. Photocatalysis measurements revealed that 2% Wt of CNT possesses the highest photocatalytic activity in the visible light irradiation with 93.1% photodegradation of malachite green (MG) as a test dye. The enhanced photocatalytic performance can be due to the large surface area, excellent conductivity performance, and high absorption ability in the visible light region. The synergistic effect of the factors mentioned above makes BiSI/BiOI/CNT nanocomposite a high-performance photocatalyst under visible light irradiation. An appropriate reaction mechanism of dye photodegradation has suggested according to the result of active species trapping experiments.

Shuttle-like CeO2/g-C3N4 composite combined with persulfate for the enhanced photocatalytic degradation of norfloxacin under visible light

In this work, the shuttle-like CeO₂ modified g-C₃N₄ composite was synthesized and was combined with persulfate (PS) for the efficient photocatalytic degradation of norfloxacin (NOR) under visible light. Scanning and transmission electron microscopy (SEM and TEM), X-ray diffraction (XRD), UV-vis diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) emission spectra were used to characterize the structural and optical properties of the as-prepared catalysts. Active species trapping experiments demonstrated that additional sulfate radicals (·SO₄^-) formed upon the addition of PS which could cooperate with superoxide radicals (O₂^-), holes (h⁺) and hydroxyl radicals (OH) to decompose NOR. Singlet oxygen (¹O₂) was also formed during the reaction and acted as an important active species. The degradation products of NOR were also identified and analyzed by using LC-MS technology, and the possible degradation mechanism and pathways were proposed and discussed. This work indicated that the shuttle-like CeO₂ modified g-C₃N₄ coupled with PS displayed promising applications in the field of pharmaceutical wastewater purification.