Green synthesis of manganese-doped superparamagnetic iron oxide nanoparticles for the effective removal of Pb(ii) from aqueous solutions

Abstract

In the current study, pure and manganese-doped superparamagnetic iron oxide nanoparticles (Mn-doped SPIONPs) were successfully prepared by a green approach using a fresh aqueous extract of Asparagus officinalis as a reducing and stabilizing agent. Magnetic behaviors of pure and Mn-doped SPIONPs were measured at room temperature against various field strengths by a vibrating sample magnetometer (VSM). The saturation magnetization was in the range of 5.39–2.07 emu. Absorption at 340 nm in the UV-visible spectrum confirmed the presence of iron oxide nanoparticles (IONPs). The presence of plant extract as a capping agent was confirmed by Fourier transform infrared (FTIR) spectroscopy. The crystalline nature of IONPs was confirmed by X-ray diffraction. A gradual increase in size was observed with increasing concentration of Mn. The synthesized materials were applied successfully as sorbent for the effective removal of lead ions (Pb(ii)). Experimental results of adsorption were also analyzed by Langmuir and Freundlich isotherm equations at different temperatures. The results suggested that sorption processes were spontaneous, and the synthesized SPIONPs displayed PbII removal capacity at higher loadings with q m of 21.3 and 29.56 mg·g−1 for undoped and 7% Mn-doped IOPNs, respectively, as compared to the commercial activated carbon.

Novel Synthesis of CuO/GO Nanocomposites and Their Photocatalytic Potential in the Degradation of Hazardous Industrial Effluents

“…In acidic media, i.e., pH < 5.6, the surface of the CuO/GO photocatalyst is charged positively by the surface species (CuO/GO−OH 2 + ) and can strongly interact with negatively charged organic compounds (6) These results showed that MR photodegradation is affected by acidic or alkaline media rather than the zero-point charge (pH = pzc) of the CuO/GO photocatalyst. Since the electric charge density is zero at pH = 5.6 on the surface of the CuO/ GO photocatalyst, the constant (K) was calculated from the first-order kinetic plot.…”

“…As a continuation of recent efforts in the green synthesis of metal-oxide nanoparticles, ,, in the present work, we have synthesized graphene oxide and CuO/GO nanocomposites. As graphene/metal-oxide nanohybrids can bring visible light into environmental applications, they also function well as a photocatalyst for the removal of organic dyes such as methyl orange (MO), methylene blue (MB), methyl red (MR), eosin (EO), and Alizarin red (AR).…”

“…A more efficient way to get rid of these toxins combines all of the existing procedures (physical, chemical, and biological) . Due to its ease, low cost, and lack of toxicity, adsorption is one of the most promising physical methods for eliminating these dyes. , However, toxins cannot be completely extracted or degraded when this procedure is performed alone; instead, they are concentrated via absorption and become impossible to remove from the environment. Other methods that are frequently used to remediate contaminated wastewater include chemical oxidation, membrane filtration, coagulation/flocculation, and mixing processes .…”

All-inorganic lead halide perovskites for photocatalysis: a review

“…Among the various pollutants, synthetic dyes such as rhodamine B, 279–281 Sudan red III, 282–285 methyl red, 286–288 methyl violet, 289–293 malachite green, 294,295 acid black dye, 296–299 Congo red, 300 and methyl orange 301–303 are common. Feng et al created CsPb(Br 1− x Cl x ) 3 -Au nanoheterojunction materials, 271 which were used to decompose Sudan red III pollutants, and the results showed that after 6 hours of visible light exposure, the heterostructures had degraded 71% of Sudan dye.…”