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Optical characterization of NiO nanoparticle-decorated single-walled carbon nanotubes synthesized via ultrasonic-assisted sol-gel method
(Elsevier BV, 2025-09)
Seyedeh Maryam Banihashemian
;
Hesam Kamyab
;
Shahabaldin Rezania
;
Daniel Simancas-Racines
;
Saravanan Rajendran
The decoration of carbon nanotubes with metal oxide nanoparticles has been employed to enhance their intrinsic properties and expand their applicability across various technological fields. This study investigated the functionalization of single-walled carbon nanotubes (SWCNTs) by treating them with a 3:2 mixture of sulfuric acid and nitric acid, which introduces oxygen-containing functional groups to enhance their dispersibility and reactivity. Nickel oxide nanoparticles (NiONPs) were synthesized and integrated onto the functionalized SWCNTs using an ultrasonic-assisted sol-gel technique, allowing uniform distribution. Then, the NiONP/SWCNT composite was evaluated for thermal stability and elemental composition via thermogravimetric analysis (TGA) and energy-dispersive X-ray spectroscopy. Both field emission scanning electron microscopy and high-resolution transmission electron microscopy confirmed the successful decoration of NiONPs (particle size <20 nm, mean value of 7.87 ± 3.02 nm) on the SWCNTs. Fourier-transform infrared spectroscopy revealed characteristic peaks corresponding to NiO at 644 cm−1 as IR-active modes induced by NiO–SWCNT and Raman spectroscopy further verified the chemical bonding between NiONPs and SWCNTs. This shows shifts in the radial breathing mode and G bands of SWCNTs, indicative of strong interfacial chemical interactions. Optical analysis demonstrated that the NiO-SWCNT nanocomposite exhibited a reduced band gap compared to pure NiO nanoparticles but a broader band gap than intermediate-phase SWCNT configurations. In addition, UV–Vis spectroscopy identified a prominent absorption peak within the 600–800 nm wavelength range, aligning with the near-infrared (NIR) spectral region. This enhanced NIR absorption suggests improved light-capturing efficiency, which could significantly benefit applications in photocatalysis and optoelectronics.
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Exploring the potential of metal and metal oxide nanomaterials for sustainable water and wastewater treatment: A review of their antimicrobial properties
(Elsevier BV, 2023-09)
Hesam Kamyab
;
Shreeshivadasan Chelliapan
;
Gasim Hayder
;
Mohammad Yusuf
;
Mohammad Mahdi Taheri
Metallic nanoparticles (NPs) are of particular interest as antimicrobial agents in water and wastewater treatment due to their broad suppressive range against bacteria, viruses, and fungi commonly found in these environments. This review explores the potential of different types of metallic NPs, including zinc oxide, gold, copper oxide, and titanium oxide, for use as effective antimicrobial agents in water and wastewater treatment. This is due to the fact that metallic NPs possess a broad suppressive range against bacteria, viruses, as well as fungus. In addition to that, NPs are becoming an increasingly popular alternative to antibiotics for treating bacterial infections. Despite the fact that most research has been focused on silver NPs because of the antibacterial qualities that are known to be associated with them, curiosity about other metallic NPs as potential antimicrobial agents has been growing. Zinc oxide, gold, copper oxide, and titanium oxide NPs are included in this category since it has been demonstrated that these elements have antibacterial properties. Inducing oxidative stress, damage to the cellular membranes, and breakdowns throughout the protein and DNA chains are some of the ways that metallic NPs can have an influence on microbial cells. The purpose of this review was to engage in an in-depth conversation about the current state of the art regarding the utilization of the most important categories of metallic NPs that are used as antimicrobial agents. Several approaches for the synthesis of metal-based NPs were reviewed, including physical and chemical methods as well as “green synthesis” approaches, which are synthesis procedures that do not involve the employment of any chemical agents. Moreover, additional pharmacokinetics, physicochemical properties, and the toxicological hazard associated with the application of silver NPs as antimicrobial agents were discussed.
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Metformin-modified polyethersulfone magnetic microbeads for effective arsenic removal from apatite soil leachate water
(Elsevier BV, 2024-01)
Shakila Kalami
;
Ekaterina Diakina
;
Roya Noorbakhsh
;
Sina Sheidaei
;
Shahabaldin Rezania
Arsenic is the hazardous species and still is the global challenge in water treatment. Apatite soil is highly rich in arsenic species, and its mining presents various environmental issues. In this study, novel magnetic microbeads as adsorbent were developed for the elimination of hazardous arsenic ions from apatite soil's aqueous leachate before discharging into environment. The microbeads were fabricated with metformin polyether sulfone after being doped with zero-valent iron (Met-PES/ZVI). The microbeads were characterized using various techniques, including FTIR, XRD, SEM-EDX, VSM, and zeta potential analysis. The developed adsorbent demonstrated a significant elimination in arsenic in aqueous leachate, achieving 82.39% removal after 30 min of contact time, which further increased to 90% after 180 min of shaking. The kinetic analysis revealed that the pseudo-second-order model best represented the adsorption process. The intra-particle diffusion model indicated that the adsorption occurred in two steps. The Langmuir model (R2 = 0.991), with a maximum adsorption capacity of 188.679 mg g−1, was discovered to be the best fit for the experimental data as compared Freundlich model (R2 = 0.981). According to the thermodynamic outcome (ΔG < −20 kJ/mol), the adsorption process was spontaneous and involved physisorption. These findings demonstrate the potential of magnetic Met-PES/ZVI microbeads as an efficient adsorbent for the removal of arsenic from apatite soil aqueous leachate.
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Metal–organic framework‐enabled biomass conversion technologies for microalgae bio‐refinery in the food industry
(Wiley, 2024-08-08)
Sujatha Sadana
;
Manivasagan Rajasimman
;
Senthil Kumar Sanjay
;
Viswanathan Kishore
;
Balasubramani Senthil Rathi
Biomass is a valuable renewable energy adapted as an alternative to traditional fossil fuels. Apart from fuels, biomass is synthesized into highly valuable products that are used in various forms including biofuels, biochemical, bioproducts, packing material, and find practice in pharmaceutical, cosmetics, and nutraceuticals industries. Particularly, microalgae a third‐generation feedstock known for its rich carbon content possesses protein lipids and carbohydrates produces a variety of green products such as bioethanol, biohydrogen, biodiesel, and biomethane, and also fixes carbon emission to a certain amount in the atmosphere. However, microalgae conversion in the presence of a catalyst such as a metal–organic framework (MOF) yields high‐quality valuable products. A MOF is a porous crystalline material where the structure and pore size can be controlled making it suitable for catalytic reactions and appropriate conversion paths. This review briefly explains the prevailing status of microalgae as a sustainable biomass and features its components for microalgae biorefinery into valuable products and its application in the food industry. MOF properties, characteristics and various MOF‐based conversion technologies for biomass conversion with its application are elaborated. In addition, usage of value products produced from microalgae biorefinery in the food industry and its importance is elucidated. In addition, the challenges in integrating biorefinery processes with food industry operations and their solutions are also presented.
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Optimization of syngas production from co-gasification of palm oil decanter cake and alum sludge: An RSM approach with char characterization
(Elsevier BV, 2024-04)
Kunmi Joshua Abioye
;
Noorfidza Yub Harun
;
Suriati Sufian
;
Mohammad Yusuf
;
Ahmad Hussaini Jagaba
The study explores co-gasification of palm oil decanter cake and alum sludge, investigating the correlation between input variables and syngas production. Operating variables, including temperature (700–900 °C), air flow rate (10–30 mL/min), and particle size (0.25–2 mm), were optimized to maximize syngas production using air as the gasification agent in a fixed bed horizontal tube furnace reactor. Response Surface Methodology with the Box-Behnken design was used employed for optimization. Fourier Transformed Infra-Red (FTIR) and Field Emission Scanning Electron Microscopic (FESEM) analyses were used to analyze the char residue. The results showed that temperature and particle size have positive effects, while air flow rate has a negative effect on the syngas yield. The optimal CO + H2 composition of 39.48 vol% was achieved at 900 °C, 10 mL/min air flow rate, and 2 mm particle size. FTIR analysis confirmed the absence of C─Cl bonds and the emergence of Si─O bonds in the optimized char residue, distinguishing it from the raw sample. FESEM analysis revealed a rich porous structure in the optimized char residue, with the presence of calcium carbonate (CaCO3) and aluminosilicates. These findings provide valuable insights for sustainable energy production from biomass wastes.

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