Greener approach towards the synthesis of titanium dioxide nanostructures with exposed {001} facets for enhanced visible light photodegradation of organic pollutants

Green chemistry is considered as an effective alternative for the conventional chemistry in the perspective of environmental sustainability. The principles of green chemistry can be applied to the field of nanotechnology especially for the synthesis of nanomaterials. In the current work, we have demonstrated an eco-friendly and inexpensive plant-mediated green method for the synthesis of visible light active titanium dioxide (TiO₂) nanoparticles with exposed high-energy {001} facets using the leaf extract of Chromolaena Odorata. The synthesized nanoparticles were analyzed using UV–Vis spectroscopy, X-ray diffraction (XRD), FTIR spectroscopy, Photoluminescence (PL) spectroscopy, X-ray photoelectron spectroscopy (XPS), and high-resolution transmission electron spectroscopy (HRTEM). Studies showed that phytochemicals present in the plant extract act as both reducing agent and capping agent in the synthesis. The photocatalytic activity of the synthesized materials was determined by analyzing the photodegradation of four different dyes such as methylene blue, fuchsine, crystal violet, and rhodamine 6G. All the dyes showed more than 85% degradation in 180 min. When compared with the chemically synthesized materials, the green synthesized TiO₂ showed a better photocatalytic activity. The superior photocatalytic performance of the sample is mainly attributed to the presence of defects and co-existence of {001} and {101} facets. The method described here leads to a new route for the synthesis of visible light active TiO₂ nanoparticles with exposed {001} facets.