Efficient osmosis-powered production of green hydrogen

Hydrogen, a clean energy carrier, has emerged as a promising solution to decarbonize the power sector and move towards a more sustainable future. However, the heavy dependence of its production on fossil fuels highlights the pressing need to prioritize the acquisition of green hydrogen from renewable sources, ideally without any additional energy input. Here we utilize the osmotic energy between seawater and freshwater to generate hydrogen directly. With a tandem of high-performance ion exchange membrane and electrocatalytic electrode, our design serves to harvest osmotic energy and drive hydrogen production. Notably, the integrated device demonstrates a consistent alkaline hydrogen evolution rate exceeding 300 l m −2  h −1 for more than 12 days under the artificial salinity gradient. Our study presents a viable pathway for hydrogen production through renewable sources.