A semitransparent particulate photoanode composed of SrTiO3 powder anchored on titania nanosheets

The development of semitransparent photoanodes is necessary to permit the construction of tandem-type photoelectrochemical (PEC) cells for water splitting in conjunction with an appropriate photocathode as the bottom cell. The fabrication of photoelectrodes from particulate material is especially desirable as a means of obtaining economically viable artificial photosynthetic systems. However, there have been no reports of efficient particulate semitransparent photoanodes applicable to tandem-type PEC cells. In this study, a particulate semitransparent photoanode composed of SrTiO3 (STO) powder anchored on a layer of titania nanosheets (TNSs) is demonstrated. The TNS layer functioned to anchor the particulate material and also served as a conductive layer. A tandem-type PEC cell combining a particulate semitransparent STO photoanode and a particulate Cu1.9Sn0.38Ge0.62S3 (CTGS) photocathode as the top and bottom cells, respectively, successfully performed overall water splitting without an external bias voltage under simulated sunlight. The present study provides a novel and versatile methodology for the fabrication of semitransparent photoanodes from particulate photocatalytic material.