Looks like it's still an active area of research (the catalyst bit, not necessarily the sunlight bit): https://www.chemistryworld.com/news/ideal-water-splitting

Looks like it's still an active area of research (the catalyst bit, not necessarily the sunlight bit): https://www.chemistryworld.com/news/ideal-water-splitting-catalysts-actually-exist-simulations-find/4010741.article https://www.chemistryworld.com/news/ideal-water-splitting-ca...