Enhancing water purification efficiency through adsorption and photocatalysis: models, applications, and challenges

ABSTRACT

One of the major global environmental challenges is the absence of potable water for the effective operation of various domestic, agricultural, industrial and other functions. At different levels of research and development, several water treatment/purification technologies have been developed. Adsorption and photodegradation technologies are among the most acceptable ones because they can be operated at an environmentally friendly level with less sophisticated technology and at a low cost. The adsorption process separates contaminants/pollutants from the solution phase onto the surface of the adsorbent while photocatalysed degradation converts the toxic contaminants to harmless forms. This paper addresses the link between the two phenomena and reviews recent nanomaterials for both processes and finally presents metal nanoparticles, metal oxide nanoparticles and metal-metal oxide nanocomposites as useful materials for both adsorption and photocatalysis. Adsorption is addressed as the initial process for the photocatalysed degradation of organic materials. The adsorption process, unlike photocatalysis, is effective for various forms of pollutants (including organic and inorganic, photocatalysed degradation is effective for organic pollutants. Reviews of the various nanomaterials as adsorbents or photocatalysts have indicated that their particle size, surface area, adsorption capacity, band gap, optical property, electrical property, porosity, and large surface are to volume ratio are factors that present them as unique materials for adsorption and photocatalysis.

KEYWORDS:

• Adsorption
• Contamination
• photodegradation
• purification
• water and wastewater

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed online at https://doi.org/10.1080/03067319.2023.2295934

Additional information

Funding

The materials used for the development of this work were sponsored by the Tertiary Education Trust Fund of Nigeria through the National Research Fund (NRF) under the Principal Investigator, Prof. Nnabuk Okon Eddy.