A solar cell that breathes in moisture for energy generation

Aiming at energy issues, alternative energy sources to fossil fuels such as solar energy, wind energy and wave energy have been well studied. However, ubiquitous atmospheric moisture as a possible alternative has not been seriously explored. Comprising of nearly 13 trillion kiloliters of water, atmospheric moisture can be best exploited as a sustainable energy resource and an abundant hydrogen source. In our present study, we have exploited moisture absorption from the air and ensuing conversion into electricity. To effectuate moisture absorption and energy conversion, a hybrid solar device was constructed by integrating tailored hygroscopic materials with photosystems stimulated by metal free organic dyes. The hygroscopic materials absorb water from humid atmospheres, serving as the source of neutral water for the photoelectrochemical reaction, thereby transducing atmospheric humidity directly into electricity and hydrogen, in the presence of light. We have also reported a significant drop in the humidity levels of a confined space from 80% to 40%. This hybrid system, when in operation, effectuates simultaneous dehumidification and a photocurrent generation of 240μA/cm2 under ambient indoor light.