Common chemicals' liquid suspension stores solar energy as chemical potential and releases it as hydrogen gas on demand even at night

https://techxplore.com/news/2026-01-demand-hydrogen-fuel-production-dark.html

"graphitic carbon nitride absorbs sunlight/ generates electrons transferred to/ stored in ammonium metatungstate metal-oxygen cluster which turns from yellow to blue (charged)... adding platinum-based catalyst generates hydrogen gas immediately... creates internal electric field accelerating electron transfer...  3,220 (in darkness)/ 954 µmol g⁻¹ h⁻¹ (under sunlight) production rates... hydrogen can be produced immediately, or charged liquid transported to energy-poor areas safely for on-demand use there"