Oxygen‐Vacancy‐Introduced BaSnO3−δ Photoanodes with Tunable Band Structures for Efficient Solar‐Driven Water Splitting

• DOI: 10.1002/adma.201903316
• Publication Date: 2019-06-27T09:15:03Z
• Authors: Myeongjin Kim; Byeongyong Lee; Hyun Ju; Jin Young Kim; Jooheon Kim; Seung Woo Lee
• Keywords: Photocurrent; Perovskite solar cell; Oxygen evolution; Reversible hydrogen electrode

Abstract To achieve excellent photoelectrochemical water‐splitting activity, photoanode materials with high light absorption and good charge‐separation efficiency are essential. One effective strategy for the production of satisfying these requirements is to adjust their band structure corresponding bandgap energy by introducing oxygen vacancies. A simple chemical reduction method that can systematically generate vacancies in barium stannate (BaSnO 3 (BSO)) crystal introduced, which thus allows precise control energy. BSO optimum oxygen‐vacancy concentration (8.7%) exhibits light‐absorption capabilities. After deposition FeOOH/NiOOH evolution cocatalysts on its surface, this shows a remarkable photocurrent density 7.32 mA cm −2 at potential 1.23 V versus reversible hydrogen electrode under AM1.5G simulated sunlight. Moreover, tandem device constructed perovskite solar cell an operating 6.84 stable gas average solar‐to‐hydrogen conversion 7.92% 100 h, functioning as outstanding unbiased system.