title: Reductive-degradation of carcinogenic azo dyes using Anacardium occidentale testa derived silver nanoparticles.
abstract: In the present work, reductive-degradation of azo dyes such as congo red (CR) and methyl orange (MO) was manifested using Anacardium occidentale testa derived silver nanoparticles (AgNPs) as a catalyst. The formation of highly stable AgNPs were visually confirmed by the appearance of yellow color and further substantiated by the existence of surface plasmon resonance (SPR) peak around 425nm. The effect of A. occidentale concentration, reaction time and pH in the formations of AgNPs was corroborated by UV-visible (UV-Vis) spectroscopy. The Fourier transform infrared (FT-IR) spectroscopic results proved that phytoconstituents of A. occidentale testa acts as a capping agent and thereby protects the AgNPs from aggregation. The crystalline nature of the AgNPs was validated from the XRD patterns. The average size of synthesized AgNPs was 25nm, with distorted spherical shape was ascribed from the high resolution transmission electron microscopic (HR-TEM) images. Due to the high stability of the as-synthesized AgNPs, they were utilized for the degradation of carcinogenic azo dyes such as CR and MO using NaBH4 and its catalytic activity was studied via UV-Vis spectroscopy. The results proved that extraordinary catalytic activity of synthesized AgNPs towards the reductive-degradation of both CR and MO.
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea. Electronic address: jebakumar84@yu.ac.kr.
authors.forename: Thomas Nesakumar Jebakumar Immanuel
authors.initials: TNJI
authors.lastname: Edison
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea.
authors.forename: Raji
authors.initials: R
authors.lastname: Atchudan
authors.affiliation: Department of Chemistry, Gandhigram Rural Institute - Deemed University, Gandhigram - 624 302, Dindigul District, Tamil Nadu, India. Electronic address: mgsethu@gmail.com.
authors.forename: Mathur Gopalakrishnan
authors.initials: MG
authors.lastname: Sethuraman
authors.affiliation: School of Chemical Engineering, Yeungnam University, Gyeongsan 712-749, Republic of Korea. Electronic address: yrlee@yu.ac.kr.
authors.forename: Yong Rok
authors.initials: YR
authors.lastname: Lee
mesh_terms: D031021:Anacardium / Q000737:chemistry* / Q000378:metabolism; D001391:Azo Compounds / Q000737:chemistry*; D002384:Catalysis; D004396:Coloring Agents / Q000737:chemistry*; D003224:Congo Red / Q000737:chemistry; D055772:Green Chemistry Technology; D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission; D010316:Particle Size; D010936:Plant Extracts / Q000737:chemistry; D012834:Silver / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D017550:Spectroscopy, Fourier Transform Infrared; D020349:Surface Plasmon Resonance; D014961:X-Ray Diffraction
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D010936:Plant Extracts; D012834:Silver; D003224:Congo Red; C100258:methyl orange
keywords: Anacardium occidentale testa; Azo dyes; Catalyst; Congo red; Methyl orange; Reductive-degradation; Silver nanoparticles