Engineering Hierarchically Grooved Structures for Enhancing Interfacial Solar Thermal Water Purification

Area of Science:

• Materials Science
• Environmental Engineering
• Photocatalysis

Background:

• Inclined interfacial solar evaporators, particularly those using microgrooved aluminum (Al) substrates, are promising for water purification.
• Performance degradation due to corrosion and contamination limits the service life of these solar evaporators.
• There is a need for strategies to enhance the durability and efficiency of solar evaporators for polluted water treatment.

Purpose of the Study:

• To develop a durable and efficient solar evaporator for purifying polluted water.
• To improve the anticorrosion properties and antibacterial capabilities of microgrooved Al substrates.
• To enhance the degradation of organic pollutants and prolong the service life of solar evaporators.

Main Methods:

• Fabrication of a renewable heterojunction using atomic layer deposition (ALD) with titanium dioxide (TiO2) as the inner layer and zinc oxide (ZnO) as the outer layer on microgrooved Al substrates.
• Evaluation of anticorrosion protection, antibacterial activity against adhered and planktonic bacteria.
• Assessment of photoinduced reactive oxide species generation for organic pollutant degradation and improvement of water evaporation rate through enhanced wicking and photothermal conversion.

Main Results:

• The TiO2/ZnO heterojunction provided effective anticorrosion protection and demonstrated efficient killing of adhered and planktonic bacteria.
• The heterojunction generated abundant photoinduced reactive oxide species, leading to the degradation of organic pollutants.
• Enhanced water wicking and photothermal conversion improved the water evaporation rate, and photodegradation/hydroxyl radical regeneration endowed the substrates with renewable wicking performance and prolonged service life.

Conclusions:

• The developed renewable TiO2/ZnO heterojunction on microgrooved Al substrates offers a practical strategy to improve the performance and extend the service life of inclined interfacial solar evaporators.
• This approach effectively addresses corrosion and contamination issues, enabling efficient purification of polluted water.
• The findings contribute to the advancement of solar-driven water treatment technologies for sustainable water resource management.