To what extent do the nanostructured photoelectrodes perform better than their macrocrystalline counterparts?

A look at recent literature dealing with photoelectrochemical (PEC) water splitting might suggest using nanostructured semiconductors to build the photoelectrodes as being a kind of panacea to enhance their energy conversion efficiency. Taking example of the most frequently investigated photoanode materials, we show the actual situation as being largely contrasted going from a substantial improvement to a spectacular drop of the PEC performance.