Microwave-Assisted Synthesis of Hollow Microspheres with Multicomponent Nanocores for Heavy-Metal Removal and Magnetic Sensing

Abstract

The primary advantage of a hollow structure is the likelihood of introducing diverse components in a single particle to achieve multiple missions. Herein, hollow microspheres with multicomponent nanocores (HMMNs) have been prepared based on a template-free strategy via a microwave-assisted hydrothermal treatment of Chlorella. The resulting HMMNs retain the nearspherical hollow morphology and functional groups of the cell wall of Chlorella, obviating the need for templates and chemical modification. The elements (iron, cobalt, calcium, magnesium, chlorine, and phosphorus) naturally present within the Chlorella cells react to form hydroxyapatite/chlorapatite and magnetic nanocores without the need for exogenous chemical reagents. The performances of HMMNs for cadmium ion (Cd 2+ ) removal and antibiotic detection are explored. HMMNs exhibit relatively high adsorbance of Cd 2+ (1035.8 mmol/kg) and can be easily recovered by application of an external magnetic field. Ion exchange with Ca 2+ and Mg 2+ is shown to be the main mechanism of Cd 2+ elimination. In addition, HMMNs are a suitable carrier for the construction of a magnetic immunosensor, as demonstrated by the successful development of such an immunosensor with acceptable analytical performance for the detection of neomycin in milk samples. The versatile applications of HMMNs result from their multicomponent nanocores, hollow structure, and the functional groups on their shell. This work not only offers a simple and eco-friendly strategy for the fabrication of novel HMMNs but also provides a valuable advanced material for contaminant detection and heavy-metal removal.

Preparation of Bioaerogel from Iron-Rich Microalgae for the Removal of Water Pollutants

“…During this process, the protoplast inside the CP cells was removed, and hollow cell walls whose main component was cellulose were obtained. The amorphous regions of cellulose will undergo alkaline degradation through a peeling-off reaction under high pH conditions [29,30]. As shown in Figure 2b,c, many particles could be observed, which was due to the formation of FexOy inside the hollow shell.…”

Microgels as Smart Polymer Colloids for Sensing and Environmental Remediation

“…They also show mutagenic, teratogenic, and carcinogenic behaviors, which cause major peril to human health, aquatic life, and ecosystems. − Detailed information on some pollutants in the current content is given in Table . Consequently, the elimination of heavy metals and dyes from pollutants is of great significance from the perspective of environmental remediation. , To address these issues, various methods have been developed to treat such water pollutants. − Among various adsorbents reported in the literature, microgel-based adsorbents are significantly important. In the past few years, a good number of microgel-based adsorbents were reported in the literature such as, polyamine-based microgel, N -isopropylacrylamide (NIPAM)-based microgel, and composite microgel for the elimination of dyes and heavy metal ions.…”

Denatured proteins show new vitality: Green synthesis of germanium oxide hollow microspheres with versatile functions by denaturing proteins around bubbles

“…The structure and character of nanomaterials determine their function and applications. In particular, as a kind of distinctive morphology, hollow microsphere (HMS) structures have been widely used in various fields, including catalysis, [1,2] sensing, [3,4] ion batteries, [5,6] supercapacitors, [7] photochemical solar cells, [8] and drug delivery, [9,10] due to their hollow structure, unique optical and electrical properties, large surface area, and good electronic transfer channels. However, most HMS materials are usually synthesized by either hydrothermal methods or hard template methods, which suffer from high security requirements, complicated template removal procedures, high temperatures (even calcination), and the use of harmful surfactants or organic solvents.…”

“…However, most HMS materials are usually synthesized by either hydrothermal methods or hard template methods, which suffer from high security requirements, complicated template removal procedures, high temperatures (even calcination), and the use of harmful surfactants or organic solvents. [3][4][5][6][7][8][9] Therefore, it is urgent and interesting to develop a convenient and green synthesis method for HMS materials.…”