Nanostructured photocatalysis in the visible spectrum for the decontamination of air and water

ABSTRACT

Photocatalytic remediation aligns with the zero waste schemes of waste and wastewater industries with low cost, environment-friendly and sustainable treatment technologies. Efforts are made to increase the photocatalytic activity of photocatalysts (titanium oxide (TiO₂), zinc oxide (ZnO) and tungsten oxide (WO₃)) by altering their shape (nanowires, nanotubes, nanoparticles, etc.), size and doping (nitrogen, metal and carbon). The photocatalytic properties of various photocatalysts in visible light radiation have been reviewed critically. The nanostructure, doping and composite formation of photocatalysts have profound impact on the remediation of various organics in both air and water. The article also emphasises on attempts to enhance the contact of insoluble pollutants by the use of surfactants and biosurfactants in photocatalytic remediation methods. The comparative photocatalytic activities using doping, surfactants and biosurfactants have been discussed to show the effective remediation of organics under visible light. This review depicts, as the first attempt, organic remediation in visible light using various photocatalytic materials.

KEYWORDS:

• Visible light photocatalyst
• TiO₂
• ZnO
• WO₃
• nanocomposite
• nanowire
• nanoparticle
• nanotube
• organics
• remediation
• surfactant
• sol–gel
• hydrothermal

Acknowledgement

The authors are grateful to Michael McCrory for his support and critical criticism during the development of this manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Srikanth Gunti http://orcid.org/0000-0001-6516-8128

Manoj K. Ram http://orcid.org/0000-0002-6833-5566

Additional information

Funding

The photocatalytic research was supported by National Science Foundation project with [grant number 1066649].