Sustainable Synthesis of Silver Nanoparticles Using Marine Algae for Catalytic Degradation of Methylene Blue

Rajendran Suresh Babu,Raji Atchudan,Ashok K Sundramoorthy,Rajangam Vinodh,Chandra Kishore Somasundaram,Thomas Nesakumar Jebakumar Immanuel Edison,Muthulakshmi Alagan,Yong Rok Lee,Suguna Perumal

doi:10.3390/catal11111377

Abstract

Herein, Sargassum coreanum (marine algae)-mediated silver nanoparticles (AgNPs) were successfully synthesized by a simple reduction method. The synthesized AgNPs were characterized using ultraviolet-visible spectroscopy, attenuated total reflection Fourier transformed infrared spectroscopy, X-ray diffractometry, field emission scanning electron microscopy (FESEM) with energy-dispersive X-ray (EDX) spectroscopy, and high-resolution transmission electron microscopy (HR-TEM) analysis. The acquired colloidal AgNPs were strongly absorbed around 420 nm and displayed brown color under visible light. The XRD pattern of AgNPs exposed their face-centered cubic geometry along with crystalline nature. The HRTEM images of synthesized AgNPs confirmed the mean particle size of 19 nm with a distorted spherical shape, and the calculated interlayer distance (d-spacing value) was about 0.24 nm. Further, the catalytic degradation of methylene blue using sodium borohydride and AgNPs was monitored using UV–vis spectroscopy. The result revealed that AgNPs performed as a superior catalyst, which completely degraded MB in 20 min. The rate constant for MB degradation was calculated to be 0.106 min−1, demonstrating that the marine algae-mediated AgNPs had outstanding catalytic activity. This approach is easy and environmentally benign, which can be applied for environmental-based applications such as dye degradation and pollutant detoxification.

Highlights

The algae extract shows two major absorbance peaks in the UVregion at 220 and 275 nm attributed to the π–π* and n–π* transitions of phytoconstituents, while the synthesized AgNPs mainly absorbed in the visible region at 420 nm and display brown color due to the surface plasmon resonance of AgNPs
The prepared AgNPs were employed as a catalyst in the degradation of methylene blue (MB) using NaBH4, which was done in a quartz UV cuvette
We present a green synthesis of AgNPs from marine algae extract that is easy, quick, and economical

Summary

Introduction

Because of its bright color and toxicity, the presence of this dye in the effluent can pose a serious hazard viz., stomach pain, vomiting, and dysentery to individuals and indirectly affect the ecosystem [12] Physical methodologies such as adsorption [13], precipitation [14], and reverse osmosis [15]; chemical techniques such as oxidation [16] and reduction [17]; and biological methods such as aerobic and anaerobic intervention have all been often used to clean dye-containing wastewaters [18]. On the other hand, overdosing on MB can produce central nervous system toxicity; its breakdown is both environmentally and physiologically essential Noble metal nanoparticles, such as Au, Ag, Pd, Pt, and Cu, have been extensively studied for efficient catalytic reduction and decoloration of dyes in an aqueous phase at room temperature [19,20,21,22,23]. The Sargassum coreanum was utilized as a perfect reducing and stabilizing agent for the synthesis of AgNPs towards MB degradation

Characterization of the Prepared Silver Nanoparticles

Dye Degradation Efficiency of the Prepared Silver Nanoparticles

Materials

Preparation of Silver Nanoparticles

Catalytic Degradation Measurements

Conclusions