Harnessing evaporation: a mini review on advances in hydrovoltaic technology for green energy generation

The Earth offers a valuable clean energy source, with a considerable percentage of its solar energy captured through water bodies. Harnessing this potential, hydrovoltaic technology offers an innovative and sustainable approach to reduce the reliance on non-renewable energy sources by converting thermal energy into electrical energy through water evaporation. This environmentally friendly technology supports human prosperity and sustainable development. Recent advancements in energy harvesting from water evaporation have significantly enhanced the integration of renewable energy into self-powered systems. A broad range of materials, including carbon black, reduced graphene oxide, metal oxides, metal derivatives, and composites, have been engineered to meet the stringent prerequisites for energy production. This review systematically explores the diverse materials that have demonstrated efficacy in generating electricity via evaporation-induced mechanisms. Furthermore, we discuss the influence of variations in material and device design in amplifying the output voltage, highlighting their transformative potential. The applications of hydrovoltaic energy are spread across various domains, including energy storage, sensing technologies, and water desalination, and thus, the future perspectives on advancing hydrovoltaic technology are also provided, emphasizing its pivotal role in fostering sustainable energy solutions. This mini-review aims to inspire further innovation in this promising field, bridging the gap between renewable energy research and practical applications.