Both the sun and water are natural companions since they are both made up mostly of hydrogen. But, the problems always has been and continues to be that breaking the bonds of hydrogen and oxygen in water has taken too much energy to be economically viable.
Researchers at the Dalian Institute of Chemical Physics in China have developed a unique catalyst that aids the creation of H2 in an efficient matter. Typically, hydrogen can be produced using sunlight in two different ways. The first method is to use solar panels to capture sunlight, create an electrical current and electrolyze water.
The second method, the one we’re talking about here, is direct solar to hydrogen conversion. In the past, photocatalysts have been limited in their use since most will only split water using ultraviolet light, which is a narrow band of the light spectrum that comes from the sun.
Synthetic catalysts developed by other researchers using light in the visible range have experience quantum efficiency of hydrogen from water in the 60-percent range. The Dalian researchers, however, using a 3-component catalytic semiconductor plus visible light have a quantum efficiency of around 93-percent.
According to C&EN, “The catalyst, prepared from cadmium sulfide doped with low concentrations of palladium sulfide and platinum, does not convert water into hydrogen and oxygen. It evolves hydrogen alone and does so only from water solutions containing sulfur-based “sacrificial” reagents that consume oxygen.”
Critics have long heralded that “brute force” electrolysis of water takes too much energy to produce hydrogen in a practical manner and they are right. But, as more effective and efficient novel catalysts are developed, the critics become less right and science marches on developing solutions that will one day lead to a cost effective hydrogen future.