Water security represents one of the major challenges to the sustainable development of human society. However, rapid population growth, steadily improving living standards, climate change, and environmental pollutions place enormous pressures on already stressed water resource systems. In addition, large amounts of energy are consumed to produce clean water and to treat wastewaters prior to their return to the environment, which inevitably leads to a considerable amount of carbon dioxide (CO₂) emissions. Developing sustainable energy-driven water production systems that enable a sustainable and cost-effective strategy for water production would benefit both developing and developed countries alike and address one of the outstanding challenges of the 21^st century: how to provide a safe and reliable source of water for a growing global population.