Rapid water disinfection using vertically aligned MoS₂ nanofilms and visible light

Area of Science:

• Materials Science
• Environmental Science
• Nanotechnology

Background:

• Solar water purification typically relies on UV light, which is inefficient, accounting for only 4% of solar energy.
• Slow treatment speeds limit the effectiveness of current solar water disinfection methods.
• Developing materials that utilize visible light for water disinfection is crucial for enhancing solar purification efficiency.

Purpose of the Study:

• To develop novel materials for efficient solar water disinfection using visible light.
• To investigate the potential of few-layered vertically aligned MoS2 (FLV-MoS2) films for water purification.
• To enhance the speed and efficiency of solar water disinfection.

Main Methods:

• Fabrication of few-layered vertically aligned MoS2 (FLV-MoS2) films with a tunable bandgap.
• Modification of FLV-MoS2 with a copper film to enhance photocatalytic activity.
• Testing the disinfection efficiency of FLV-MoS2 under visible light and simulated sunlight using indicator bacteria.

Main Results:

• FLV-MoS2 effectively harvests visible light (approx. 50% of solar energy) for water disinfection.
• Increased bandgap of FLV-MoS2 (1.3 to 1.55 eV) facilitates reactive oxygen species (ROS) generation for bacterial inactivation.
• FLV-MoS2 demonstrated ~15 times higher log inactivation efficiency than bulk MoS2 and outperformed TiO2.
• A copper-coated FLV-MoS2 film achieved >99.999% bacterial inactivation in 20 minutes under visible light.

Conclusions:

• FLV-MoS2 films are highly efficient visible-light-driven photocatalysts for water disinfection.
• The developed material significantly accelerates solar water purification compared to existing technologies.
• This approach offers a promising solution for rapid and effective solar-based water treatment.