 Over the next few decades, the world's energy supply is likely to become dominated by solar power. To get there, researchers will have to solve an important problem, storing solar energy for use at night or under cloudy conditions. One solution is to use sunlight to split water into hydrogen and oxygen, and store the hydrogen portion to top up vehicles and devices running on fuel cells. Getting the right material to split water efficiently presents an entirely new set of challenges, but a likely candidate might be on the horizon. By surrounding a popular water-splitting material with an all-star cast of supporting materials, researchers from Japan generated hydrogen with record efficiency. Water-splitting electrodes work much like the leaves of a plant during photosynthesis. They absorb energy from sunlight and use it to generate charge carriers, negatively charged electrons, and the positively charged holes the electrons leave behind. They then deliver those charges to water. Power molecules swipe electrons away to form hydrogen gas, whereas holes strip the molecules of electrons to form oxygen gas. The ideal water-splitting electrode, therefore, should be an efficient light absorber, charge separator, and charge conductor. Unfortunately, few materials fit the full bill. Bismuth Vanadate, for instance, one of today's best and cheapest water-splitters, is a decent absorber, but a poor conductor. To tackle this problem, the team developed an electrode incorporating a trio of materials, each dedicated to a different task. They retained Bismuth Vanadate as a light absorber, but spread it thinly over highly-conductive tungsten oxide nanorots to make up for its poor charge-shuffling ability. And to make sure every hole does its job, the team added a cobalt catalyst to jump-start the formation of oxygen gas. With this blend of materials, the team was able to boost the solar-to-hydrogen conversion efficiency to 8.1%, which is 90% of the theoretical maximum for Bismuth Vanadate. And further improvements to the design, such as finding a way to up the device's built-in voltage, could push that number even higher. Ultimately, this new water-splitting scheme may pave the way toward cheaper and better ways of harnessing the sun's energy. Day and night.