Abstract:

Water evaporation-driven hydrovoltaic generators (HGs) with the property of sustainable electricity generation
offer the promise of clean and renewable power. Despite recent efforts to advance HGs by enhancing solid-liquid
interface interactions and nanopore structures design, extremely scarce usable natural water source and slow
heat replenishment remain obstacles. Here, we demonstrated a solar thermal conversion boosted hydrovoltaic
power generation system (HPGS) by rationally integrating environmental water harvesting patterned coating,
solar steam generator and hydrovoltaic functional coating with solar thermal conversion capability. In the
system, the water collected or readily available in the environment with high ion concentration (conductivity of
505.95 μS cm􀀀 1) is purified by a solar steam generator into a low conductivity pure water (~ 6.32 μS cm􀀀 1) to
supply for HGs, realizing the solution to the water source limitation for HGs. The Al2O3/CB nanoparticles
constructed hydrovoltaic functional coating exhibits remarkable solar thermal conversion ability to raise device
temperatures by over 18 ◦C, resulting an increase of Voc by 130.7% from 2.54 V to 5.86 V at 50% RH under 1
standard sun radiation. Such HPGS based on solar thermal conversion makes it possible for HGs to directly use
the environmental available water and break through the shackles of restricted ambient temperature and slow
heat replenishment.