Developing simple and effective photocatalysis systems is vital for water treatment applications.
Study: Efficient MnO2 decorated graphitic carbon nitride-based nanocomposite for application in water purification. Image Credit: LI CHAOSHU/Shutterstock.com
In a paper published in Materials Today: Proceedings, a unique MnO2-decorated graphitic carbon nitride nanocomposite was produced in-situ for water purification through the photocatalytic breakdown of Rhodamine B (RhB) dye.
An Introduction to Nanomaterials
Nanotechnology is regarded as one of the most influential technologies of the twenty-first century. Nanomaterials have structures with diameters ranging from approximately 100 nm to 1 nm. Their distinct physicochemical and surface features contribute to producing innovative materials and technological solutions to challenges that have proven difficult to tackle with traditional methods.
Nanomaterials exhibit several desirable qualities, including high strength, small mass, and active surfaces having significant catalytic capabilities.
Importance of Nanotechnology in Water Purification
People all over the world are affected by a shortage of safe drinking water and a lack of basic sanitation. Several efforts have been undertaken to tackle the undeniable environmental, economic, and social concerns caused by a shortage of clean drinking water and basic sanitation.
Further research for using nanotechnology as a means of water purification has become a top priority because of the emergence of promising technologies.
Water purification and treatment requires unique nanoparticles with the ability to remove hazardous organic contaminants from water swiftly, effectively, and inexpensively.
Fabricating unique nanoparticles with strong selectivity and affinity for contaminants is a fast-developing field of research in nanotechnology.
The dimensions and form of nanoparticles may be altered using different synthesis processes, including chemical vapor deposition, sol-gel, and pyrolysis.
How Can Photocatalysis Help in Water Purification?
Photocatalysis is a highly sophisticated approach to addressing environmental issues that influence an ecosystem and the well-being of its inhabitants.
Organic contaminants in wastewater may be broken down into water, carbon dioxide (CO2), and other small components, while inorganic contaminants may be reduced or oxidized to non-toxic chemicals, via photocatalysis.
Graphitic carbon nitride (GCN) is an inexpensive, non-toxic, metal-free photocatalyst. It has a visible-light driven bandgap and can tolerate aqueous settings.
Secondary pollution produced by commonly used metallic photocatalysts may be prevented through graphitic carbon nitride, which is a significant advantage of using graphitic carbon nitride in practical applications.
Importance of Energy Bandgap for Photocatalysis
Energy bandgap is an important characteristic of semiconductors, and it also influences the photocatalytic behavior of graphitic carbon nitride. To achieve optimal photocatalysis, the energy bandgap between the conduction and valence bands should not be greater than 3 eV.
A material with less than 3 eV energy bandgap captures visible light and exhibits enhanced photocatalytic properties.
The use of photocatalytic materials is limited because of narrow energy bandgaps, material instabilities, and fast recombination.
To address the limiting factors of photocatalytic materials, different strategies like the use of metal oxide nanoparticles etched on carbon-based materials, doping of nonmetals and metals, and the fabrication of heterogeneous nanocomposites have been used.
What Did the Researchers Do?
In this study, the team developed a unique MnO2-decorated graphitic carbon nitride nanocomposite for water purification through the breakdown of RhB dye.
The characteristics of RhB dye were investigated in two different settings: with and without the addition of sodium borohydride (NaBH4).
The team also determined the energy bandgap of the produced nanocomposite using a Tauc plot acquired using a UV-visible spectrophotometer and carried out structural characterization with the help of XRD and FTIR analysis.
The team fabricated nanoparticles of graphitic carbon nitride, MnO2 and GCN/MnO2 and performed structural characterizations using FTIR and XRD analysis.
They found the bandgap energy of the produced nanocomposite equaled 2.75 eV. Graphitic carbon nitride and MnO2 had bandgap energies of 3.3 and 3.25 eV , respectively, which were larger than the nanocomposite's bandgap energy.
The team used the synthesized materials for the breakdown of RhB dye, and they also recorded the activity parameter, rate constant, and reduction time of the breakdown processes.
The breakdown of RhB dye was examined in two settings: under the influence of sunshine and under the influence of the additive NaBH4. The photocatalytic performance and rate constant of the GCN/MnO2 nanocomposite in the breakdown processes were observed to be greater than those of individual graphitic carbon nitride and MnO2 for both reaction settings.
Vikal, M., Shah, S. et al. (2022). Efficient MnO2 decorated graphitic carbon nitride-based nanocomposite for application in water purification. Materials Today: Proceedings. Available at: https://www.sciencedirect.com/science/article/pii/S2214785322049586?via%3Dihub