In a study available in the journal Materials Today: Proceedings, silver nanoparticles (Ag NPs) were fabricated using a green method using Citrus X sinensis.

Methylthioninium Chloride (MB) Dyes Threatening the Environment

Dye and sewage drainage into waterways by factories is a significant ecological issue. The dye produced by large textile factories and other businesses has major environmental consequences.

MB dyes, which pose major ecological concerns, are among the substantial quantities discharged. The cationic MB (methylthioninium chloride) dye is very acidic in nature, causing damage to underwater life as well as the well-being of humans.

How can Nanoparticles Help in Mitigating Pollution?

Nanotechnology has an important and decisive role in pollution elimination. Nanoparticle (NP) research has gained popularity in the last couple of decades owing to the exceptional properties of nanoparticles and their numerous applications. The large surface-to-volume ratio of NPs boosts their beneficial qualities.

Green manufactured NPs have been proven to have greater relevance in the breakdown of dyes than chemically fabricated NPs, resulting in a novel strategy for tackling water contamination concerns.

Biological Synthesis of Nanoparticles – The Way Forward

Chemical techniques of NP fabrication use more energy, are more expensive and employ hazardous chemicals. In comparison, the biological creation of NPs uses lesser energy, is inexpensive, and uses only harmless chemicals.

Many botanical components, including stems, roots, leaves, and flowers were employed in the extract to fabricate NPs. Several therapeutic plants, including Lippia citriodora, Alpinia nigra, Kalanchoe pinnata, and Gmelina arborea, have recently been used to synthesize silver nanoparticles (Ag NPs).

The Role of Silver Nanoparticles

Ag NPs have piqued the interest of scientists due to their distinctive qualities such as chemical and photonic stability, as well as catalytic, optoelectronic and antibacterial characteristics. The catalytic process has been identified as among the most successful dye removal strategies. Owing to their active pore locations, Ag NPs maximize their catalytic properties.

Using Citrus X sinensis for Synthesis of Silver Nanoparticles

Citrus is an evergreen plant that is thriving in the Brazilian area. It can also be seen in South China, Myanmar, and Northeast India. This species belongs to the Rutaceae family. Colloquially referred to as sweet orange, Citrus X sinensis has been claimed to possess medicinal and antioxidant properties.

The occurrence of carbohydrates, alkaloids, flavonoids, phenolics, tannins, triterpenes, and saponins was discovered in Citrus X sinensis extracts. The fruits of Citrus X sinensis were utilized to fabricate Ag NPs in this research. After experiencing a photocatalyzed reduction in ultraviolet light, the Citrus X sinensis-coated Ag NPs were used to break down the MB dye.

Examining the Catalytic Activity of Produced Silver Nanoparticles

The catalytic performance of green fabricated Ag NPs for MB was investigated under direct sunlight. In 100 milliliters of 30 ppm methylthioninium chloride dye solution, a 10-milligram catalyst was introduced. Prior to illumination, the solution was stirred for 15 minutes in darkness to reach adsorption and desorption equilibrium.

The process continued to progress when exposed to sunshine. The dye breakdown process was conducted by subjecting the solution to sunlight at different time durations. The solution was centrifuged after each exposure to sunlight to remove the catalyst.

Key Findings of the Study

For the synthesis of Ag NPs in this study, a green and efficient process was adopted. Citrus X sinensis fruit extract was used to successfully generate Ag NPs. These fruit extracts were demonstrated to cause a reduction of AgNO₃ to produce Ag NPs.

Characterization results from ultraviolet-visible analysis demonstrated that the Citrus X sinensis fruit extract had a significant influence on the stability of the synthesized nanoparticles. SEM scans confirmed the formation of sphere-shaped NPs with a uniform size distribution.

Green Ag NPs were shown to be efficient in catalyzed reduction of methylthioninium chloride dyes. Moreover, the nanoscale catalyst reusability investigation revealed that the catalyst is robust enough for repetitive usage. The photocatalyzed breakdown data showed that Ag NPs deteriorated 82.2 percent of the MB dye in 75 minutes.

This study’s results suggested that biologically synthesized silver nanoparticles made from Citrus X sinensis fruit extract are suitable for photocatalytic activity.