Super adsorption performance of carboxymethyl cellulose/copper oxide-nickel oxide nanocomposite toward the removal of organic and inorganic pollutants

Investigation of the Electrochemical Behavior of CuO-NiO-Co3O4 Nanocomposites for Enhanced Supercapacitor Applications

In the present study, composites incorporating NiO-Co3O4 (NC) and CuO-NiO-Co3O4 (CNC) as active electrode materials were produced through the hydrothermal method and their performance was investigated systematically. The composition, formation, and nanocomposite structure of the fabricated material were characterized by XRD, FTIR, and UV-Vis. The FE-SEM analysis revealed the presence of rod and spherical mixed morphologies. The prepared NC and CNC samples were utilized as supercapacitor electrodes, demonstrating specific capacitances of 262 Fg-1 at a current density of 1 Ag-1. Interestingly, the CNC composite displayed a notable long-term cyclic stability 84.9%, which was observed even after 5000 charge-discharge cycles. The exceptional electrochemical properties observed can be accredited to the harmonious effects of copper oxide addition, the hollow structure, and various metal oxides. This approach holds promise for the development of supercapacitor electrodes. These findings collectively indicate that the hydrothermally synthesized NC and CNC nanocomposites exhibit potential as high-performance electrodes for supercapacitor applications.

Recent advances in carboxymethyl cellulose-based active and intelligent packaging materials: A comprehensive review

Researchers have concentrated on innovative approaches to increase the shelf life of perishable food products and monitor their quality during storage and transportation as consumer demand for safe, environmentally friendly, and effective packaging develops. This comprehensive review aims to provide an overview of recent developments in carboxymethyl cellulose (CMC) chemical synthesis and its applications in active and intelligent packaging materials. It explores various methods for modifying cellulose to produce CMC and highlights the unique properties that make it suitable for addressing packaging industry challenges. The integration of CMC into active packaging systems, which helps reduce food waste and enhance food preservation, is discussed in depth. Furthermore, the integration of CMC in smart sensors and indicators for real-time monitoring and quality assurance in intelligent packaging is examined. The chemical synthesis of CMC and strategies to optimise its properties were studied, and the review concluded by examining the challenges and prospects of CMC-based packaging in the industry. This review is intended to serve as a valuable resource for researchers, industry professionals, and policymakers interested in the evolving landscape of CMC and its role in shaping the future of packaging materials.

Rationally designed carboxymethylcellulose-based sorbents crosslinked by targeted ions for static and dynamic capture of heavy metals: Easy recovery and affinity mechanism

A separable spherical bio-adsorbent (CMC-Cr) was prepared for capturing heavy metal ions by simple coordination and cross-linking between targeted ions of Cr³⁺ and carboxymethyl cellulose (CMC). A simple alternation of the CMC incorporation allowed the interconnected networks within the microspheres of preformed solid CMC to be adjusted. The excellent network structure could achieve the maximum collision between the adsorbent and the heavy metal cations in the wastewater. Through investigations, CMC-Cr-2 beads were determined as the optimal adsorbent. The adsorption performance of novel materials was evaluated by examining their adsorption behavior on Pb(II) and Co(II) under both static and dynamic conditions. The results showed that the adsorption behavior of CMC-Cr-2 beads on both two heavy metal cations could be fully reflected by the Freundlich model. Under the theoretical conditions, the maximum adsorption capacities were 97.26 and 144.74 mg/g. The kinetic results for the adsorption of two heavy metal cations on CMC-Cr-2 beads were consistent with the Pseudo-second-order kinetic model. Moreover, the correlation coefficient of the Thomas model was significant in the dynamic adsorption performance tests. Five regeneration cycle studies were successfully carried out on CMC-Cr-2 beads to evaluate reusability and stability. The applicability of CMC-Cr-2 beads in authentic aqueous solutions (both the single and binary pollutant systems) was also studied, and the results indicated that CMC-Cr-2 beads had a high potential for practical implementation. Furthermore, by analyzing the surface interactions of two heavy metal cations with the CMC-Cr-2 beads based on FTIR and XPS characterization, a basic understanding of the interaction between bio-sorbents and pollutants in wastewater can be obtained.

Selective adsorption of iron(III) ions based on nickel(II) oxide-copper(II) oxide nanoparticles

Background:

Water contamination and its remediation are currently considered a major concern worldwide. Design of effective methods for water purification is highly demanded for adsorption and removal of such pollutants.

Objective:

This study depicts the effectiveness of nickel oxide-copper oxide nanoparticles (NiO-CuO), which can extract and remediate ferric ions, Fe (III), from aqueous solutions.

Methods:

The NiO-CuO nanoparticles were simply prepared by the co-precipitation method and then used as adsorbent with respectable advantages of high uptake capacity and surface area.

Results:

Adsorption of Fe(III) onto NiO-CuO nanoparticles showed an uptake capacity of 85.86 mgg−1 at pH 5.0. The obtained data from the carried-out experiment of Fe (III) adsorption onto NiO-CuO nanoparticles were well suited to the Langmuir isotherm and pseudo-second-order kinetic models. Moreover, different coexisting ions did not influence the adsorption of Fe(III) onto NiO-CuO nanoparticles. The recommended methodology was implemented on the adsorption and removal of several environmental water samples with high efficiency.

Conclusion:

The design method displayed that NiO-CuO nanoparticles can be used as promising material for the adsorptive removal of heavy metals from water.

Chitosan@Carboxymethylcellulose/CuO-Co2O3 Nanoadsorbent as a Super Catalyst for the Removal of Water Pollutants

In this work, an efficient nanocatalyst was developed based on nanoadsorbent beads. Herein, carboxymethyl cellulose-copper oxide-cobalt oxide nanocomposite beads (CMC/CuO-Co2O3) crosslinked by using AlCl3 were successfully prepared. The beads were then coated with chitosan (Cs), Cs@CMC/CuO-Co2O3. The prepared beads, CMC/CuO-Co2O3 and Cs@CMC/CuO-Co2O3, were utilized as adsorbents for heavy metal ions (Ni, Fe, Ag and Zn). By using CMC/CuO-Co2O3 and Cs@CMC/CuO-Co2O3, the distribution coefficients (Kd) for Ni, Fe, Ag and Zn were (41.166 and 6173.6 mLg-1), (136.3 and 1500 mLg-1), (20,739.1 and 1941.1 mLg-1) and (86.9 and 2333.3 mLg-1), respectively. Thus, Ni was highly adsorbed by Cs@CMC/CuO-Co2O3 beads. The metal ion adsorbed on the beads were converted into nanoparticles by treating with reducing agent (NaBH4) and named Ni/Cs@CMC/CuO-Co2O3. Further, the prepared nanoparticles-decorated beads (Ni/Cs@CMC/CuO-Co2O3) were utilized as nanocatalysts for the reduction of organic and inorganic pollutants (4-nitophenol, MO, EY dyes and potassium ferricyanide K3[Fe(CN)6]) in the presence of NaBH4. Among all catalysts, Ni/Cs@CMC/CuO-Co2O3 had the highest catalytic activity toward MO, EY and K3[Fe(CN)6], removing up to 98% in 2.0 min, 90 % in 6.0 min and 91% in 6.0 min, respectively. The reduction rate constants of MO, EY, 4-NP and K3[Fe(CN)6] were 1.06 × 10-1, 4.58 × 10-3, 4.26 × 10-3 and 5.1 × 10-3 s-1, respectively. Additionally, the catalytic activity of the Ni/Cs@CMC/CuO-Co2O3 beads was effectively optimized. The stability and recyclability of the beads were tested up to five times for the catalytic reduction of MO, EY and K3[Fe(CN)6]. It was confirmed that the designed nanocomposite beads are ecofriendly and efficient with high strength and stability as catalysts for the reduction of organic and inorganic pollutants.

Copper Oxide-Antimony Oxide Entrapped Alginate Hydrogel as Efficient Catalyst for Selective Reduction of 2-Nitrophenol

Copper oxide-antimony oxide (Cu₂O-Sb₂O₃) was prepared and entrapped inside Na-alginate hydrogel (Alg@Cu₂O-Sb₂O₃). The developed Alg@Cu₂O-Sb₂O₃ was used as catalytic reactor for the reduction of 4-nitrophenol (4-NP), 2-nitrophenol (2-NP), 2,6-dinitrophenol (2,6-DNP), methyl orange (MO), congo red (CR), acridine orange (AO), methylene blue (MB) and potassium ferricyanide (K₃[Fe(CN)₆]). Alg@Cu₂O-Sb₂O₃ was found to be selective and more efficient for the reduction of 2-NP among all the pollutants. Therefore, 2-NP was selected for a detailed study to optimize various parameters, e.g., the catalyst amount, reducing agent concentration, 2-NP concentration and recyclability. Alg@Cu₂O-Sb₂O₃ was found to be very stable and easily recyclable for the reduction of 2-NP. The Alg@Cu₂O-Sb₂O₃ nanocatalyst reduced 2-NP in 1.0 min, having a rate constant of 3.8187 min⁻¹.

Sodium alginate nanocomposite based efficient system for the removal of organic and inorganic pollutants from wastewater

An effective and selective catalytic system based on cerium oxide-stannous oxide (CeO₂-SnO) wrapped Na-alginate hydrogel was developed for the selective reduction of potassium ferricyanide (K₃[Fe(CN)₆]). Na-alginate hydrogel was used as a reacting container for CeO₂-SnO nanoparticles. Na-alginate wrapped CeO₂-SnO (Alg/CeO₂-SnO) was applied as a catalyst and examined toward the reduction of several hazardous pollutants, such as nitrophenols, dyes and K₃[Fe(CN)₆]. Alg/CeO₂-SnO nanocatalyst was mostly selective toward K₃[Fe(CN)₆] since it was more effective and economical for reduction of K₃[Fe(CN)₆]. Further different parameters like catalyst amount, reducing agent amount, K₃[Fe(CN)₆] concentration and recyclability were optimized. The increase in both nanocatalyst amount and NaBH₄ concentration resulted in increasing the rate of the catalytic reduction of K₃[Fe(CN)₆]. Alg/CeO₂-SnO nanocatalyst reduced K₃[Fe(CN)₆] in 4.0 min with a reaction rate constant of 0.9114 min^-1. The nanocatalyst can be easily recovered by pulling the hydrogel from the reaction medium up to four cycles. Alg/CeO₂-SnO nanocatalyst was also examined in real samples like irrigation water, sea water, well water, university water, which was effective for K₃[Fe(CN)₆] reduction by 95.16%-96.54%. This novel approach provides a new catalyst for efficient removal of K₃[Fe(CN)₆] from real samples and can be a time and cost alternative tool for environmental safety.