Characterization of morphological structures of Fe3O4/SiO2/ZnO composite

The coprecipitation method has been successfully used for the synthesis and characterization of composite Fe3O4/SiO2/ZnO. The purpose of this research was to lower the concentrations of heavy metals in the water in an effort to restore natural functioning of the water. Because of its excellent chemical properties and high biocompatibility, silica is an intriguing and renewable material. The mixing magnetic materials Fe3O4 and ZnO can provide efficient separation effects, increase test sensitivity, and reduce detection time. The modification Fe3O4 with %wt ZnO (5; 10; 15;20) uses rice husk ash as a substitute for SiO2 in the application of heavy metal ion wastewater absorption, the aim is to minimize the composition of recyclable metal ion content which is environmentally friendly. The characterization of composite Fe3O4/SiO2/ZnO using SEM-EDS for morphological analysis and mapping of the elements that make up the sample The composite Fe3O4/SiO2/ZnO has gaps between its particles and a homogeneous shape, as seen by the SEM images.


Introduction
The increase in the amount of wastewater resulting from both industrial and household disposal has resulted in the need for renewed research in terms of wastewater absorption of heavy metal ions.The applicant has carried out a lot of research, especially in the field of magnetic materials.In the present, the supply of clean water is decreasing.The lack of clean water arises due to several reasons such as the fastest population increase and the increase in the number of developing industries.The development of industry in Indonesia has recently grown very rapidly.Timbangen et.al, 2022 [1] have succeeded in identifying the effect of adding TiO2 to Fe3O4/SiO2 showing that there is an influence of magnetic properties, morphology, band gap energy, and photocatalytic properties of the catalyst which influence the photocatalyst process in degrading organic compounds (methylene blue) effectively and optimal, with 2Ɵ values around 32,720 and 32,450 with a peak area of (220).
There are an increasing number of waste byproducts of industrial production as industry grows.Heavy metals that are disposed of as waste are one type of such waste.The specified metallic elements include Cu (copper), Cd (cadmium), Pb (lead), and Cr (chromium).Human activity has the potential to cause pollution of the water.The careless disposal of about 80% of the wastewater produced worldwide pollutes rivers, the environment, and the oceans.The WHO and UNICEF estimate that 2.5 billion people do not have adequate sanitation [2].
Medan is the capital of the province North Sumatra has a population of 2,460,858 people in 2022 [3].One method to get water back to working order and lower the amount of heavy metals in it is through the adsorption of heavy metals.One of the adsorbent materials that is utilized is magnetic because it allows for fast and simple separation of the absorbent from the solution using a magnetic field, resulting in high removal efficiency of contaminants [4].
The Fe3O4 with chitosan composite has been used as an adsorbent for heavy metals [5].However, it is known that the mechanical stability of Fe3O4 with chitosan is still low.The physical properties of chitosan and Fe3O4 can be improved if they are modified on the silica surface.One source of silica that can be easily found is rice husks [6].Silica dioxide is an amorphous and crystalline chemical compound consisting of silica and oxygen.The synthesis SiO2 involves a reaction between silica and oxygen at high temperatures using vacuum techniques, hydrolysis techniques and electrolysis techniques.SiO2 is a metal oxide compound that is widely found in nature, but not in a free state but bound to other compounds.
The physical and chemical properties of SiO2 can be biocompatible, functioned become the bond it is also ionic and internal to a fairly large surface area [7].The magnetite is widely used in solid phase extraction because it is paramagnetic.It has also been modified with various inorganic and organic materials [8].Fe3O4 has the characteristic black color and ferromagnetic consist of Fe 2+ and Fe 3+ ions [9].The magnetic moment resulting from cations occupying tetrahedral and octahedral sites are identical, despite their orientation opposite [10].
Processing waste uses the silica dioxide acts as an adsorbent can help speed up degradation reactions and convert it into forms that are safer or easier to remove [11].So that, rice husks can be utilized properly, they must be further processed into husk charcoal or husk ash.More husk charcoal it is used as a planting medium because it still has a large volume, while husk ash is more often used as fertilizer because it has a smaller volume [12].

Methods
The preparation of Fe3O4/SiO2 by the coprecipitation method begins by dispersing Fe3O4.into ethanol solution.After that, concentrated NH4OH is added to the Fe3O4 solution.Using a magnetic stirrer, the process is completed, and the precipitate is then cleaned with aquarists and nearly-neutral ethanol pH.The material is heated to a specific temperature and then crushed with a pestle and mortar to produce uniformly sized particles.
The first for synthesis of Fe3O4/SiO2/ZnO with weighing Fe3O4/SiO2 and ZnO.After that, the stirring process is carried out with the magnetic stirrer.Then the obtained precipitate is washed with aquarists and ethanol until nearly neutral pH.After washing, the sample be calcined with certain temperature.Next, the sample is crushed using a pestle and mortar and repeat the process with 5 variations of ZnO.Then the Fe3O4/SiO2/ZnO composite was characterized using SEM-EDS for morphological analysis and mapping of sample constituent elements.

The SEM Results
A scanning electron microscope (SEM) is a microscope system that uses high-energy scattered electron beams to scan a sample, which can produce images of the surface morphology of a given sample at up to a thousand times magnification.The working principle of SEM is that it first starts with an electron bullet that produces an electron beam, and then will be accelerated by the anode.The magnetic lens in the SEM focuses electrons towards the sample, which then scans the entire sample using a scanning coil.To analyze the size and morphology of nanoparticles using SEM of Fe3O4/SiO2/ZnO particles with a 5% variation, the SEM-EDS results of Fe3O4/SiO2/ZnO composites from rice husk material with variations in heating temperature need further analysis.Emphasizing the size distribution patterns, morphological shapes, and elemental composition with variations in these parameters can provide deeper insights into the characteristics of the nanomaterial.At a temperature of 950°C.The SEM image shows that the distribution of Fe3O4 nanoparticles is uneven, such as some being large and small, and then still very rough and not smooth.In this picture, it can be seen that there is still empty space.This is caused by incomplete sample preparation.And in the morphological picture, the surface shows that there are several gaps and distances between particles.Further analysis particles shows a variation of 10% with a combustion temperature of 950°C.
The surface morphology shows that it has started to improve from before, because the parts of the particles are starting to become smoother and not as rough as before.Also in this picture you can see that the empty spaces are starting to fill up one by one and are filled with particles that have spread out to IOP Publishing doi:10.1088/1742-6596/2733/1/0120214 become smaller.Overall, the heating temperature does not have a significant effect on the surface morphology of the composite, but it does affect the elemental composition and % content.
The SEM image indicates a somewhat uniform distribution of Fe3O4 nanoparticles, with coverage starting to fill the surface between the particles.And particles with a variation of 15%.Paying attention to the SEM test results shows that there is an uneven distribution of atoms and few visible bonds between molecules.There are some particles whose distribution is still a little uneven and some are still lumpy, but this is much better even though they look blurry.In this image you can see that it is getting finer and more particles are starting to break down into smaller pieces and are starting to solidify.The SEM image is also the result of burning ground rice husks at the best temperature, namely 950°C.The image starts to look better with the position of the particles and their size, some are spread out but are still rough.
The SEM analysis reveals a 20% variation in the average size of Fe3O4/SiO2 particles.The majority exhibit a very smooth surface, yet there are one or two particles that stand out due to their larger size and perfectly smooth appearance.The SEM image is a part where the combustion temperature is 950°C and the distribution of Fe3O4 nanoparticles, of which several other variations are the only ones that look perfect, also the empty space is very difficult to find.Apart from its size being small and fine, its distribution is also even [13][14][15][16]

Conclusion
The synthesis of Fe3O4/SiO2/ZnO composites with %wt ZnO (5; 10; 15;20) the successful implementation of a process involving the extraction of SiO2 from rice husk ash at different heating temperatures has been accomplished.Particle size distribution and SEM-EDS images indicate that there are numerous clusters exhibiting the characteristic morphology of Fe3O4 nanoparticles in the distribution of the particles.The heating temperature does not have a significant effect on the surface morphology of the composite, but it does affect the elemental composition and % content.Temperature variations did not appear to have any appreciable effects on surface morphology.It is the heating temperature that affects the elemental composition and levels, though.