Biogenically structural and morphological engineering of Trigonella foenum-graecum mediated SnO2 nanoparticles with enhanced photocatalytic and antimicrobial activities

Abstract

The increasing water pollution and infectious diseases in the current globalization are the signals for the high demand of advanced materials for their treatment in near future. In this regard, the present work presents an advanced, easy and low-cost biogenic process for the synthesis of Trigonella foenum-graecum@SnO2 as a photocatalyst and an antimicrobial agent. The particles are characterized through X-ray diffractometer, scanning electron microscope, transmission electron microscope, Fourier infrared transform spectrometer and UV–Visible spectrometer. Debye Scherrer, Williamson–Hall and the Modified Debye Scherrer equations give an average crystallite size of about 10 nm. FTIR spectrum shows the presence of many biological and organic moieties in the Trigonella foenum-graecum extract acting as both capping and reducing agent, and various functional groups such as carboxyl, hydroxyl, fat and alcohol, are observed on the surface of Trigonella foenum-graecum mediated SnO2 nanoparticles. The larger bandgap of SnO2 nanoparticles (2.60 eV) as compared to its bulk counterpart (3.60 eV) is attributed to the quantum confinement of its excitons. SEM and TEM analysis show nanosized spherical particles with a clear frame of the passivating agent. SnO2 nanoparticles are found to be an efficient photocatalyst in the degradation of toxic Coralene Red dye with degradation efficiency of 100% and high photodegradation rate-constant of 9.65 × 10−3 min−1. As an antimicrobial mediator, the SnO2 nanoparticles are effective against E. coli (gram-negative) and B. subtilis (gram-positive) with different zones of clearance.