Title: Ag decorated iron Titanate nanohybrids as visible light active photo catalyst in micropropagation applications

Abstract

Micropropagation techniques are commonly used to produce large quantities of healthy plants in commercial agriculture. In this technique, all plant parts used in vitro experiments should be free of microorganisms. Therefore, vigorous surface sterilization is carried out. Chemical sterilization based on HgCl2, NaOCl, alcohol, benzalkonium chloride and peroxide (H2O2) are commonly used at commercial scale and some of these compounds are known to be highly carcinogenic and toxic. Therefore, these practices, impose threats to both humans and the environment. Photocatalytic sterilization is identified as a safer and sustainable alternative method. In this study, an efficient photocatalytic nanohybrid material based on Ag decorated iron titanate (Ag-FeTiO3) derived from natural beach sand has been developed. FeTiO3 nanoparticles are isolated from beach sand using an acid dissolution method followed by treatment with AgNO3. Electron microscopy studies confirmed the successful anchoring of Ag nanoparticles onto the iron titanate nanoparticles separated from beach sand. The band gap of 2.80 eV calculated using UV-Vis studies confirmed its activity under visible light. The efficacy of the nanohybrid has been tested using Scindapsus aureus as the model plant. Plant nodes (40 for each experiment) were sterilized using commercial sterilizing agent 10% Clorox at 360 Lux (N1) and Ag-FeTiO3 dispersion and kept the plants under various light intensities of 290 Lux (N2), 360 Lux (N3) and 30,000 Lux (N4). Rate of contamination and propagation of the plants were monitored for a period of 90 days. It was observed that 63%, 54%, 16% and 20% contaminations were observed for Ni, N2, N3 and N4, respectively. Interestingly, high rate of node propagation (84%) was observed in the plants sterilized using nanohybrid under 360 Lux value (visible light) compared to N1 (37%). The observations confirm significantly improved sterilization efficacy in removal of microorganisms thus leading to improved rate of propagation.