Scientists at the Indian Institute of Technology (IIT) Bombay have created an innovative graphene-based material that significantly improves water desalination efficiency.
Professor Swatantra Pratap Singh and researcher Aiswarya C.L. have developed what they call a Dual-Sided Superhydrophobic Laser-Induced Graphene (DSLIG) evaporator. This new technology mimics the water-repelling properties of lotus leaves to prevent salt buildup—a common problem that reduces the effectiveness of traditional desalination equipment.
“The primary goal of our work was to create a superhydrophobic surface exhibiting the lotus effect, capable of functioning with both solar and Joule heating,” explained Professor Singh.
With less than 0.05% of Earth’s water easily accessible as freshwater, desalination of seawater and brackish water has become increasingly important. However, existing solar-powered desalination methods face challenges from inconsistent sunlight and salt accumulation.
The new DSLIG technology addresses these limitations through a hybrid approach that combines solar energy with electrical heating. This dual power source ensures the system operates effectively even during cloudy periods or nighttime, maintaining consistent performance regardless of weather conditions.
The researchers created their material by coating polyvinylidene fluoride (PVDF) onto poly(ether sulfone) (PES), then using laser engraving to incorporate graphene. The resulting surface repels water droplets much like a lotus leaf, preventing dissolved salts from adhering to the evaporator’s surface.
Laboratory tests have demonstrated DSLIG’s effectiveness not only for standard desalination but also for processing highly concentrated salt solutions, making it potentially valuable for treating industrial wastewater and brine discharge from other desalination facilities.
The technology shows even greater efficiency when multiple evaporators are stacked together, suggesting promising scalability for larger applications. However, Professor Singh noted that additional funding is needed for field testing before industrial implementation can begin.
“We are looking forward to developing more such superhydrophobic materials that can simultaneously utilize both solar and electric energy with even greater efficiency,” Singh added.
