Chicken Egg Shell Waste Derived Calcium Oxide Based Nanohybrid For Rapid Removal of Heavy Metal Ions from Water: Green Synthesis, Kinetics and Reusability

Abstract

The carcinogenic metal ions chromium (Cr + 6 ) and lead (Pb + 2 ) are prominent water pollutants. To substantiate this, green synthesized SnO 2 nanoparticle (using S. mukorossi extract) was coupled with egg shell derived CaO nanocrystals. Crystalline nature of synthesized catalyst confirmed by PXRD and microscopic study revealed spherical SnO 2 decorated on the irregular surface of CaO. Synthesized nanohybrid followed adsorption and photocatalytic reduction (Cr + 6 to Cr + 3 ; Pb + 2 to Pb 0 ) (Cr + 6 : 94 %; Pb + 2 : 88 %) phenomenon. Synergism of CaO (51.9 m 2 g À 1 ;2.9 eV) and SnO 2 (13.3 m 2 g À 1 ; 3.15 eV) was resulted into plenty of surface area (91.9 m 2 g À 1 ), low band gap (2.4 eV), and semiconducting nature of nanohybrid. As compared to Pb + 2 removal of Cr + 6 was faster due to higher value of reduction potential [Cr + 6 /Cr + 3 (1.35 eV); Pb + 2 /Pb 0 (À 0.1262 eV)]. Photocatalyst proved to be effective upto 10 th cycle. SnO 2 @CaO nanohybrid might be considered a potential photocatalyst in industries with sustainable approach.

Biosynthesized Metallic Nanoarchitecture for Photocatalytic Degradation of Emerging Organochlorine and Organophosphate Pollutants: A Review

“…The utilization of hybrid nanocomposites was supported by the PXRD spectrum, hence justifying their unhindered application for up to the 8th cycle. [98] In the study conducted by Rani et al, [131] the team examined the reusability of the photocatalysts Fe 2 O 3 and BC@Fe 2 O 3 , under optimum conditions, for the removal of endosulfan and ethion pesticides through solar irradiation. In order to regenerate the catalysts from the pesticide samples, the solution underwent centrifugation, followed by the recovery of the solid portion using filtration.…”

“…The potential suitability of the modified BC@ Fe2O3 nanohybrid as a catalyst for industrial applications is supported by its reusability (n = 7), ability to facilitate charge separation, stability, and high surface activity. [131] In another experiment, CuFe 2 O 4 magnetic nanoparticles were regenerated using ethanol as a desorbing agent by Hassanzadeh-Afruzi et al. [126] By submerging and swirling the BNP in ethanol at ambient temperature for a duration of 4 hours, the chlorpyrifos was been desorbed from the biosorbent.…”

“…These findings have been supported by previous studies. [65,127,131,132] According to the regenerability and recyclability data collected in Table 4, a biogenic nanonanophotocatalyst can be recycled and repurposed for OC and OP degradation an average of roughly six cycles, with the lowest number of recyclability being three and the highest number being eight. After the nth cycle, a nanonanophotocatalyst's average degradation capacity is higher than 78 %.…”

“…[98] desorb OP and OC from used nanophotocatalysts Among these are ethanol, [126] distilled water and acetone, [93,98] distilled water and n-hexane, [130] and centrifugation, water and acetone. [131] However, the most frequently used eluent is distilled water and n-hexane. Table 4 presents a comprehensive overview of desorption and reuse as documented in the available literature.…”

Surfactant-Capped Silver-Doped Calcium Oxide Nanocomposite: Efficient Sorbents for Rapid Lithium Uptake and Recovery from Aqueous Media

“…Recently, alkaline earth metal oxides are of great interest to researchers and have been widely used for various applications. For example: (i) magnesium oxide nanoparticles have been used for dye removal from wastewater and tissue culture applications [27,28]; (ii) barium oxide nanoparticles have been used for dye photodegradation [29]; (iii) calcium oxide nanoparticles have been used for pollutant removal [30,31], carbon dioxide adsorption [32], catalysis [33], and antimicrobial applications [34]. Among these metal oxide nanoparticles, the oxides of calcium (CaO) have been dominantly used in various applications due to their efficient physicochemical properties.…”