Toward efficient photoelectrochemical water-splitting by using screw-like SnO2 nanostructures as photoanode after being decorated with CdS quantum dots

We report the fabrication of screw-like SnO 2 nanostructure and its application as photoanode for photoelectrochemical water splitting . The structure was formed by growing thread-like SnO 2 nanosheets onto rod-like single-crystalline SnO 2 nanowires . Such a structure offers an efficient light absorption, high speed electron transport and a large surface-to-volume ratio. The light absorption efficiency of the screw-like SnO 2 nanostructures can be increased by up to 33% than that of the pristine SnO 2 nanowires. After decorated with CdS quantum dots , the photocurrent density can reach 9.9   mA   cm −2 at 0   V ( versus saturated calomel electrode) which corresponding to a hydrogen generation of 159.6   μmol (h   cm 2 ) −1 and the faradic efficiency is around 86%. The result demonstrated that the water-splitting efficiency of photoelectrochemical cell has been significantly improved by using such a screw-like structure. Our work provides an efficient solution to improve the water-splitting performance and it can also be a model structure for similar electrode materials.