The prominent benefit of granite is owned to its physicochemical property and ubiquitous nature. Vast application of granite which also includes its use as an adsorbent in environmental remediation practice, can also be enhanced. To further enhanced the uptake capacity of granite, nanocomposite consisting of multiwall carbon nanotubes (MWCNTs) and granite was fabricated and further modified using Dialiumguineensestem bark extract. The structure and composition of pristine granite (PG) and modified nanocomposite granite (G) based material were examined and confirmed by the FTIR, Raman, TGA, SEM and XRD. Meanwhile, the specific surface areasof PG (1.268 m2/g) and G (16.57 m2/g) were obtained using the BET surface area analyser. The optimization step revealed that the uptake capacities of PG and G were dependent on solution pH, sorbent dose and contact time. Meanwhile, pseudo-second-order and Elovich kinetic models were noticed to best describe the data for the removal of Cr (VI) by PG and G. Equilibrium isotherm study revealed that Freundlich and Langmuir models fitted well to the experimental data obtained for the uptake of Cr(VI) onto PG and G respectively. Furthermore, electrostaticattraction betweentheDialiumguineense stem bark extract on the surface of G and Cr(VI) influenced the uptake of Cr(VI). On the other hand, the interaction between the plant extract and Cr(VI) may result in the attenuation of Cr(VI) via reduction to Cr(III). Finally, the thermodynamically favoured adsorptive process demonstrated high adsorbent reusability with good stability for Cr(VI) uptake.
The surficial and textural features of a pyrogenic carbonaceous material (charcoal) was modulated with acidic Piranha solution (i.e., 1:3 30% H2O2 to H2SO4) to produce a redox-active adsorbent for the simultaneous adsorption and reduction of Cr(VI) in groundwater sample. The optimal modification time of 60 s is required to transform the raw charcoal to an efficacious redox-active adsorbent (MCh). The MCh surface was imbued with electron donor moieties that is required for the direct conversion of the adsorbed Cr(VI) to Cr(III). The rate parameters for Cr(VI) adsorption by the MCh were initial concentration dependent. The GW system variables had minimal influence on the performance of the MCh, which showed that the MCh is capable of effective performance within broad process variables. The direct conversion of Cr(VI) to Cr(III) on the MCh surface was affirmed. The treatment of Cr(VI) contaminated GW in a microcosm real-life system was highly effective over the period of study (40 hours). The residual Cr(VI) concentration in the hourly sample collection ranged between undetectable (i.e.,<0.01), at the inception, to 1.77 mg/L at the 40th hour. The pH values of the treated water were not vitiated, and the EC (μs cm− 1) values continually reduced over time.
An entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
Abstract Extensive investigations have been carried out on spinel mixed transition metal oxide-based materials for high-performance electrochemical energy storage applications. In this study, mesoporous Mn-substituted Mn x Zn 1−x Co 2 O 4 (ZMC) ternary oxide microspheres (x = 0, 0.3, 0.5, 0.7, and 1) were fabricated as electrode materials for supercapacitors through a facile coprecipitation method. Electron microscopy analysis revealed the formation of microspheres comprising interconnected aggregates of nanoparticles. Furthermore, the substitution of Mn into ZnCo 2 O 4 significantly improved the surface area of the synthesized samples. The electrochemical test results demonstrate that the ZMC3 oxide microspheres with an optimal Mn substitution exhibited enhanced performance, displaying the largest specific capacitance of 589.9 F g −1 at 1 A g −1 . Additionally, the ZMC3 electrode maintained a capacitance retention of 92.1% after 1000 cycles and exhibited a significant rate capability at a current density of 10 A g −1 . This improved performance can be ascribed to the synergistic effects of multiple metals resulting from Mn substitution, along with an increase in the surface area, which tailors the redox behavior of ZnCo 2 O 4 (ZC) and facilitates charge transfer. These findings indicate that the incorporation of Mn into mixed transition metal oxides holds promise as an effective strategy for designing high-performance electrodes for energy storage applications.
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