title: Stable quantum dot photoelectrolysis cell for unassisted visible light solar water splitting.
abstract: Sunlight is an ideal source of energy, and converting sunlight into chemical fuels, mimicking what nature does, has attracted significant attention in the past decade. In terms of solar energy conversion into chemical fuels, solar water splitting for hydrogen production is one of the most attractive renewable energy technologies, and this achievement would satisfy our increasing demand for carbon-neutral sustainable energy. Here, we report corrosion-resistant, nanocomposite photoelectrodes for spontaneous overall solar water splitting, consisting of a CdS quantum dot (QD) modified TiO2 photoanode and a CdSe QD modified NiO photocathode, where cadmium chalcogenide QDs are protected by a ZnS passivation layer and gas evolution cocatalysts. The optimized device exhibited a maximum efficiency of 0.17%, comparable to that of natural photosynthesis with excellent photostability under visible light illumination. Our device shows spontaneous overall water splitting in a nonsacrificial environment under visible light illumination (λ > 400 nm) through mimicking nature's "Z-scheme" process. The results here also provide a conceptual layout to improve the efficiency of solar-to-fuel conversion, which is solely based on facile, scalable solution-phase techniques.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University , 62 Nanyang Drive, Singapore 637459, Singapore.
authors.forename: Hong Bin
authors.initials: HB
authors.lastname: Yang
authors.forename: Jianwei
authors.initials: J
authors.lastname: Miao
authors.forename: Sung-Fu
authors.initials: SF
authors.lastname: Hung
authors.forename: Fengwei
authors.initials: F
authors.lastname: Huo
authors.forename: Hao Ming
authors.initials: HM
authors.lastname: Chen
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
keywords: photoelectrochemical cell; quantum dots; semiconductor; water splitting