Highly Efficient Water Oxidation Photoanode Made of Surface Modified LaTiO₂N Particles

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• 作者：Seiji Akiyama ; Mamiko Nakabayashi ; Naoya Shibata ; Tsutomu Minegishi ; Yusuke Asakura ; Md. Abdulla-Al-Mamun ; Takashi Hisatomi ; Hiroshi Nishiyama ; Masao Katayama ; Taro Yamada and Kazunari Domen
• 刊名：Small
• 出版年：2016
• 出版时间：October 19, 2016
• 年：2016
• 卷：12
• 期：39
• 页码：5468-5476
• 全文大小：2653K
• ISSN：1613-6829

文摘

An improved variation of highly active/durable O₂-evolving LaTiO₂N powder-based photoelectrode has been fabricated by pre-cleaning the powder with mild polysulfonic acid and by homogeneous deposition of CoO_x co-catalyst aided by microwave annealing. The treatment in aqueous solution of poly(4-styrene sulfonic acid) results in removal of surface LaTiO₂N layers, forming fine pores in the crystallites. The CoO_x co-catalyst by microwave deposition in Co(NH₃)₆Cl₃/ethylene glycol homogeneously covers the particle surface. The LaTiO₂N powder is fabricated into particle-transferred electrodes on Ti thin film supported on solid substrate. The modified LaTiO₂N grains on the electrode serve as a highly active O₂-evolving photoanode achieving 8.9 mA cm⁻² of the photocurrent density at 1.23 V versus reversible hydrogen electrode (RHE) in 0.1 m NaOH (pH 13) under solar-simulator irradiation Airmass 1.5 Global (AM 1.5G). The activity has been much improved, compared with conventional LaTiO₂N treated in mineral acid or with CoO_x deposited by impregnation. The new electrode also exhibits better durability in fixed-potential chronoamperometric tests under AM 1.5G irradiation.