A standalone bismuth vanadate-silicon artificial leaf achieving 8.4% efficiency for hydrogen production
Boyan Liu, Xin Wang, Yingjuan Zhang, Mingshan Zhu, Chenxin Zhang, Shaobin Li, Yanhang Ma, Wei Huang, Songcan Wang
Abstract
Abstract The development of scalable photoelectrochemical water splitting with high solar-to-hydrogen efficiency and long-term stability is essential while challenging for practical application. Here, we design a BiVO 4 photoanode with gradient distributed oxygen vacancies, which induces strong dipole fields to promote charge separation. Growing sea-urchin-like FeOOH cocatalyst on the photoanode leads to a photocurrent density of 7.0 mA cm −2 at 1.23 V versus the reversible hydrogen electrode and is stable for over 520 h under AM 1.5 G illumination. By integrating with a silicon photovoltaic cell, the standalone artificial leaf achieves a solar-to-hydrogen efficiency of 8.4%. The scale-up of these artificial leaves up to 441 cm 2 in size can deliver a solar-to-hydrogen efficiency of 2.7% under natural sunlight. Life cycle assessment analysis shows that solar water splitting has little environmental footprint for hydrogen production. Our study demonstrates the possibility of designing metal oxide-based artificial leaves for scalable solar hydrogen production.