Highly stable AgNPs prepared via a novel green approach for catalytic and photocatalytic removal of biological and non-biological pollutants

Pooja Rani, Vanish Kumar, Prit Pal Singh, Avtar Singh Matharu, Wei Zhang, Ki Hyun Kim*, Jagpreet Singh, Mohit Rawat

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

Abstract

Increases in biological and non-biological pollutants pose a significant threat to environmental systems. In an effort to develop an effective means to treat such pollutants, the use of Phaseolus vulgaris (kidney beans) as reducing and capping agents is proposed for the green synthesis of highly stable silver nanoparticles (AgNPs) with a face-centered cubic (fcc) crystalline structure (size range: 10–20 nm). The potent role of the resulting AgNPs was found as triple platforms (photocatalyst, catalyst, and antimicrobial disinfectant). AgNPs were able to photocatalytically degrade approximately 97% of reactive red-141 (RR-141) dye within 150 min of exposure (quantum efficiency of 3.68 × 10-6 molecule.photon-1 and a removal reaction kinetic rate of 1.13 × 10-2 mmol g−1 h−1). The role of specific reactive oxygen species (ROS) in the photocatalytic process and complete mineralization of dye was also explored through scavenger and chemical oxygen demand (COD) experiments, respectively. As an catalyst, AgNPs were also capable of reducing 4-nitrophenol to 4-aminophenol within 15 min. Overall, AgNPs showed excellent stability as catalyst and photocatalyst even after five test cycles. As an antimicrobial agent, the AgNPs are effective against both gram-positive (Bacillus subtilis) and -negative bacteria (Escherichia coli), with the zones of clearance as 15 and 18 mm, respectively. Thus, the results of this study validate the triple role of AgNPs derived via green synthesis as a photocatalyst, catalyst, and antimicrobial agent for effective environmental remediation.

Original languageEnglish
Article number105924
Number of pages13
JournalEnvironment International
Volume143
Early online date10 Jul 2020
DOIs
Publication statusPublished - Oct 2020

Bibliographical note

© 2020 The Author(s).

Keywords

  • 4-nitrophenol
  • Catalytic activity
  • Green synthesis
  • Phaseolus Vulgaris
  • Photocatalytic degradation
  • Silver nanoparticles

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