Tuning the properties of a black TiO₂-Ag visible light photocatalyst produced by rapid one-pot chemical reduction

Coto, Michael; Divitini, Giorgio; Dey, Avishek; Krishnamurthy, Satheesh; Ullah, Najeeb; Ducati, Cate and Kumar, R. Vasant (2017). Tuning the properties of a black TiO₂-Ag visible light photocatalyst produced by rapid one-pot chemical reduction. Materials Today Chemistry, 4 pp. 142–149.

DOI: https://doi.org/10.1016/j.mtchem.2017.03.002

Abstract

A highly efficient black TiO₂-Ag photocatalytic nanocomposite, active under both UV and visible light illumination, was synthesized by decorating the surface of 25 nm TiO₂ particles with Ag nanoparticles. The material was obtained via a rapid, one-pot, simple (surfactant and complexing agent free) chemical reduction method using silver nitrate and formaldehyde as a metal salt and reducing agent, respectively. The nanocomposite shows an increase of over 800% in the rate of photocatalytic methylene blue dye degradation, compared to commercial unmodified TiO₂, under UV-VIS illumination. Unlike pure TiO₂, the nanocomposite exhibits visible light activation, with a corresponding drop in optical reflectance from 100% to less than 10%. The photocatalytic properties were shown to be strongly enhanced by post-reduction annealing heat treatments in air, which were observed to decrease, rather than coarsen, silver particle size, and increase particle distribution. This, accompanied by a variation in the silver surface oxidation states, appear to dramatically affect the photocatalytic efficiency under both UV and visible light. This highly active photocatalyst could have wide ranging applications in water and air pollution remediation and solar fuel production.

Viewing alternatives

Metrics

Item Actions

Export

You can export this page using these formats Digital Object Identifier - DOI