Posted in | News | Nanomaterials | Nanoanalysis

Nanoparticles Enable Cost-Effective Breakdown of Polluted Water

The photocatalytic deterioration of a common fabric azo dye utilizing nanoparticles was examined in a recent study published in the journal Materials Today: Proceedings.

Nanoparticles Enable Cost-Effective Breakdown of Polluted Water

Study: Improvement in photocatalytic activity of titanium dioxide nanoparticles through doping and calcination for textile wastewater treatment under visible light. Image Credit: NatalieIme/

Here, TiO2 nanoparticles (NPs) loaded with zinc nitrate were synthesized using the sol–gel process and calcinated at elevated temperatures, resulting in the development of heterogeneous phases and increased photocatalysis by the NPs under visible light.

Advanced Oxidation Processes for Treatment of Dye-Containing Effluents

Several emerging nations significantly depend on the textiles industry to fuel their economic growth.

To achieve color requirements, reactive and azo dyes that are can easily dissolve in water are used. As a consequence, around 10–20% of the pigments used are discarded into water sources as pollutants.

Fabric dyes deteriorate bodies of water by raising biological and chemical oxygen requirements, hampering photosynthesis, inhibiting the growth of plants, and infiltrating the food chain. Pollution can also cause recalcitrant behavior and bioaccumulation, and possibly leading to highly toxic, carcinogenic, and mutagenic levels.

To minimize harmful impacts on the ecosystem, human and animal health, and fresh-water reserves, dye-carrying effluents must be adequately treated utilizing environmentally friendly technology.

Advanced oxidation processes (AOPs) have proved to be some of the most effective ways for the treatment of dye-carrying effluents.

Heterogenized photocatalysis is a highly interesting AOPs for the treatment of dyes as well as other organic substances due to its environmentally friendly qualities and minimal power and raw ingredient requirements.

Why Use Titanium Dioxide?

Titanium dioxide (TiO2) is the preferred semiconducting substance for photocatalysis-based purification of organic compounds owing to its chemical stability, inexpensive properties, non-toxic nature, and exceptional photocatalytic capabilities.

TiO2 NPs are only functional when subjected to ultraviolet irradiation since they are unable to absorb light with wavelengths higher than 398 nm.

Commercially accessible UV lamps, on the other hand, are expensive and demand a lot of power to be operated regularly.

Photocatalytic materials with high visible spectrum absorbance must be produced to best utilize the abundant resource that is sunlight or irradiation from artificial sources in photocatalysis.

Choosing the Appropriate Dopant for Titanium Dioxide

To achieve visible spectrum absorption, transition metal loading of titanium dioxide has been investigated. By exposing TiO2 to hydrogen peroxide or chelating agents, just a handful of the photocatalysis processes would progress in visible light conditions.

Photo-absorption of nitrogen-doped TiO2 occurs at wavelengths of 400 nm or higher. Sulfur-loaded TiO2 complex exhibited complete absorbance under visible light irradiation and strong action to break down aqueous-phase mixtures of methylene blue under visible light irradiation at wavelengths of 440 nm or higher.

The nitrogen-loaded TiO2 demonstrated superior photocatalytic activity in simulated sunlight, with a 100 percent reduction of Flumequine, a common water contaminant, in four hours of irradiation.

TiO2 loaded with nitrogen also displayed photocatalysis activity for 2-propanol breakdown in aqueous mixture in visible light irradiation. In the visible light range, absorption was greater.

In this study, methyl red dye was decomposed utilizing photocatalytic TiO2 NPs doped with zinc nitrate in visible light, and kinetic investigations were carried out.

The photocatalyst chosen for azo dye deterioration was calcinated at 800 °C, resulting in the development of blended phases of TiO2 in the photocatalytic nanoparticles. The influence of blended phases on photodeterioration was investigated.

Important Findings of the Study

The researchers evaluated the breakdown of model fabric effluent carrying azo dye methyl red using TiO2 NPs tailored to boost visible light photocatalysis.

It was discovered that the change of anatase to rutile phase in TiO2 happens at high temperatures and that the calcination temperature influences photocatalysis.

Anatase and rutile phase combinations may also improve photocatalytic activity. The analysis corroborated these findings, and it was discovered that a peak degradation of 85 percent was attained for 0.2 g of photocatalyst in three hours.

It was determined that the developed photocatalyst is reusable and retains its photocatalytic function. According to the kinetic investigation, the degeneration followed pseudo second order kinetics.

The results reveal that Zn(NO3)2 doped TiO2 can effectively breakdown azo dye under visible light irradiation, making it cost-efficient owing to the use of visible light.


Rao, P. A., & Satyanarayana, S. (2022). Improvement in photocatalytic activity of titanium dioxide nanoparticles through doping and calcination for textile wastewater treatment under visible light. Materials Today: Proceedings. Available at:

Disclaimer: The views expressed here are those of the author expressed in their private capacity and do not necessarily represent the views of Limited T/A AZoNetwork the owner and operator of this website. This disclaimer forms part of the Terms and conditions of use of this website.

Shaheer Rehan

Written by

Shaheer Rehan

Shaheer is a graduate of Aerospace Engineering from the Institute of Space Technology, Islamabad. He has carried out research on a wide range of subjects including Aerospace Instruments and Sensors, Computational Dynamics, Aerospace Structures and Materials, Optimization Techniques, Robotics, and Clean Energy. He has been working as a freelance consultant in Aerospace Engineering for the past year. Technical Writing has always been a strong suit of Shaheer's. He has excelled at whatever he has attempted, from winning accolades on the international stage in match competitions to winning local writing competitions. Shaheer loves cars. From following Formula 1 and reading up on automotive journalism to racing in go-karts himself, his life revolves around cars. He is passionate about his sports and makes sure to always spare time for them. Squash, football, cricket, tennis, and racing are the hobbies he loves to spend his time in.


Please use one of the following formats to cite this article in your essay, paper or report:

  • APA

    Rehan, Shaheer. (2022, March 02). Nanoparticles Enable Cost-Effective Breakdown of Polluted Water. AZoNano. Retrieved on September 29, 2023 from

  • MLA

    Rehan, Shaheer. "Nanoparticles Enable Cost-Effective Breakdown of Polluted Water". AZoNano. 29 September 2023. <>.

  • Chicago

    Rehan, Shaheer. "Nanoparticles Enable Cost-Effective Breakdown of Polluted Water". AZoNano. (accessed September 29, 2023).

  • Harvard

    Rehan, Shaheer. 2022. Nanoparticles Enable Cost-Effective Breakdown of Polluted Water. AZoNano, viewed 29 September 2023,

Tell Us What You Think

Do you have a review, update or anything you would like to add to this news story?

Leave your feedback
Your comment type