PT  - JOURNAL ARTICLE
AU  - Qiu, Yongcai
AU  - Liu, Wei
AU  - Chen, Wei
AU  - Chen, Wei
AU  - Zhou, Guangmin
AU  - Hsu, Po-Chun
AU  - Zhang, Rufan
AU  - Liang, Zheng
AU  - Fan, Shoushan
AU  - Zhang, Yuegang
AU  - Cui, Yi
TI  - Efficient solar-driven water splitting by nanocone BiVO<sub>4</sub>-perovskite tandem cells
AID  - 10.1126/sciadv.1501764
DP  - 2016 Jun 01
TA  - Science Advances
PG  - e1501764
VI  - 2
IP  - 6
4099  - http://advances.sciencemag.org/content/2/6/e1501764.short
4100  - http://advances.sciencemag.org/content/2/6/e1501764.full
SO  - Sci Adv2016 Jun 01; 2
AB  - Bismuth vanadate (BiVO4) has been widely regarded as a promising photoanode material for photoelectrochemical (PEC) water splitting because of its low cost, its high stability against photocorrosion, and its relatively narrow band gap of 2.4 eV. However, the achieved performance of the BiVO4 photoanode remains unsatisfactory to date because its short carrier diffusion length restricts the total thickness of the BiVO4 film required for sufficient light absorption. We addressed the issue by deposition of nanoporous Mo-doped BiVO4 (Mo:BiVO4) on an engineered cone-shaped nanostructure, in which the Mo:BiVO4 layer with a larger effective thickness maintains highly efficient charge separation and high light absorption capability, which can be further enhanced by multiple light scattering in the nanocone structure. As a result, the nanocone/Mo:BiVO4/Fe(Ni)OOH photoanode exhibits a high water-splitting photocurrent of 5.82 ± 0.36 mA cm−2 at 1.23 V versus the reversible hydrogen electrode under 1-sun illumination. We also demonstrate that the PEC cell in tandem with a single perovskite solar cell exhibits unassisted water splitting with a solar-to-hydrogen conversion efficiency of up to 6.2%.