Solar energy-driven evaporators: A solution to the drinking water crisis?

What is it about?

Several water purification techniques have been developed to produce potable water from impure sources. But a few drawbacks, such as high energy consumption and low economic viability, limit their use. A 2021 review looks at solar energy-driven interfacial evaporators, a new water purification technology. In these systems, sunlight is converted to heat which turns impure water into water vapour. It is this process that gives interfacial evaporators their name. The authors discuss the design, optimisation, and applications of these systems and how they purify wastewater and desalinate seawater. The evaporators are made using nano/micro-structured ‘photothermal’ materials, which convert solar energy into heat. These structured materials form a crucial part of the system, making it highly energy-efficient and high-performance. Solar-driven interfacial evaporators use four different kinds of photothermal materials: carbon-based, plasmonic metals, semi-conductors, and polymers. Additionally, a water-replenishment foam-like substrate provides continuous water supply to the heating zone of the evaporator so that the conversion cycle is continuous.

Featured Image

Photo by Linus Nylund on Unsplash

Photo by Linus Nylund on Unsplash

Why is it important?

Most of the water on Earth is not fit for human consumption. Moreover, access to clean drinking water is becoming increasingly difficult with time due to depletion of sources. To battle this scarcity, we need an economic and energy-efficient water purification system. Solar energy-driven interfacial evaporators present a sustainable solution. They use a renewable, abundant source of energy, i.e., sun to upcycle otherwise unusable water. Improving upon this innovative technology would further increase its efficiency and output, providing safe, potable water for many. KEY TAKEAWAY: Solar energy-driven interfacial evaporators are a promising system for water purification and desalination and could solve the global drinking water crisis. This research relates to the following Sustainable Development Goals: • SDG 6: Clean Water and Sanitation • SDG 7: Affordable and Clean Energy • SDG 13: Climate Action • SDG 9: Industry, Innovation, and Infrastructure