Efficient solar-driven water oxidation using particulate perovskite oxynitrides by defect engineering

通过缺陷工程利用颗粒钙钛矿氮氧化物进行高效太阳能驱动的水氧化

• 批准号: 19K15676
• 负责人: 徐 貞淑
• 金额: $ 2.66万
• 依托单位: Shinshu University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Early-Career Scientists
• 财政年份: 2019
• 资助国家: 日本
• 起止时间: 2019-04-01 至 2020-03-31
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-19K15676/
• 关键词: solar water oxidation; perovskite oxynitrides; surface defects; low onset potential; defects; oxygen evolution

The Perovskite-type BaTaO2N had been studied as a starting material for this research based on efficient solar water oxidation. BaTaO2N was successfully prepared from layered perovskite, Ba-rich Ba5Ta4O15 to suppress surface defects such as reduced species of Ta4+ and/or Ta3+ during the high temperature nitridation under NH3 flow at 1223 K for 30 h. Subsequently, the annealing treatment of the nitrided product in an Ar flow was performed to reduce additional oxygen impurities and/or nitrogen vacancy and thus to decrease the recombination of photogenerated charges during the solar water oxidation.The decreased defect densities related to Ta and O/N species on the BaTaO2N particles were determined by X-ray photoelectron spectroscopy and oxygen-nitrogen combustion analysis, respectively. These approaches were very effective at suppressing the surface defects and impurities on BaTaO2N. Consequently, the photocurrent density at 1.23 VRHE of 6.5 mA cm-2 was generated during the photoelectrochemical water splitting over a particulate BaTaO2N photoanode and the onset potential driving actual anodic photocurrent was shifted more negatively to 0.6 VRHE, providing a half-cell solar-to-hydrogen energy conversion efficiency of 1.4%. This is a new record for a photoanode based on perovskite-type AB(O,N)3.

本研究以钙钛矿型BaTaO 2N为起始材料，以高效太阳能水氧化为基础，对BaTaO 2N进行了研究。以层状钙钛矿结构的富钡Ba 5 Ta 4 O 15为原料，在1223 K氨气流中高温氮化30 h，成功地制备了BaTaO 2N，抑制了Ta 4+和Ta 3+还原态的表面缺陷。随后，氮化产物在氩气流中进行退火处理，以减少额外的氧杂质和/或氮空位，从而减少太阳能水氧化过程中的光生电荷的复合.减少的缺陷密度相关的Ta和O/N物种的BaTaO 2N颗粒上的X射线光电子能谱和氧-氮燃烧分析，分别确定.这些方法在抑制BaTaO_2N表面缺陷和杂质方面非常有效。因此，在颗粒BaTaO 2N光阳极上的光电化学水分解期间产生6.5 mA cm-2的1.23 VRHE下的光电流密度，并且驱动实际阳极光电流的起始电势更负地偏移至0.6 VRHE，提供1.4%的半电池太阳能-氢能量转换效率。这是基于钙钛矿型AB（O，N）3的光阳极的新记录。

项目成果

Solar-Driven Water Splitting over a BaTaO2N Photoanode Enhanced by Annealing in Argon

• DOI: 10.1021/acsaem.9b00908
• 发表时间: 2019-08
• 期刊: ACS Applied Energy Materials
• 影响因子: 6.4
• 作者: Jeongsuk Seo;Mamiko Nakabayashi;T. Hisatomi;N. Shibata;T. Minegishi;K. Domen

Annealing Treatments of Perovskite-type Oxynitrides in Argon for High Solar Water Oxidation Activity

钙钛矿型氮氧化物在氩气中退火处理以提高太阳水氧化活性

• 发表时间: 2019
• 作者: Jeongsuk Seo;Kazunari Domen
• 通讯作者: Kazunari Domen