Xiaojuan Bai et al. (authors of "Water engineering via surfactant coacervates enables efficient and robust solar hydrogen evolution")

Surfactant coacervates are dense, surfactant-rich liquid phases that form via liquid–liquid phase separation when surfactant mixtures in water cross certain concentration, composition, or ionic conditions, yielding a coexisting pair of liquids: a concentrated coacervate phase and a dilute aqueous phase. In the context of this work, these coacervate phases are used as engineered water microenvironments surrounding photocatalysts to improve solar hydrogen evolution.[1][6]

Photocatalytic solar hydrogen evolution is a process where semiconductor or molecular catalysts use absorbed solar photons to drive the reduction of water protons to molecular hydrogen, typically via water splitting or sacrificial-reagent-assisted reactions.[1][6] It is a key pathway to green hydrogen because it can directly convert sunlight into chemical fuel without intermediate electricity generation.

Water structure engineering via hydrogen-bond network disruption refers to deliberately modifying the arrangement and dynamics of hydrogen bonds among water molecules near catalyst surfaces to optimize reaction rates, rather than treating water as a passive solvent.[1][7][9] Related studies have shown that changing water orientation and hydrogen-bonding at interfaces, for example using Nb2O5-modified Ru nanoclusters, can enhance the hydrogen evolution reaction in neutral media.[7]