Surface-Modified Ta3N5 Photoanodes for Sunlight-Driven Overall Water Splitting by Photoelectrochemical Cells
Surface-Modified Ta3N5 Photoanodes for Sunlight-Driven Overall Water Splitting by Photoelectrochemical Cells
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DOI：
10.3390/catal11050584
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发表时间：
2021-05-01
期刊：
影响因子：
3.9
通讯作者：
Domen, Kazunari
中科院分区：
文献类型：
--
作者：
Higashi, Tomohiro;Sasaki, Yutaka;Domen, Kazunari
开发可见光响应半导体光电极是构建高效光电化学太阳能水分解电池的先决条件。在光电极上使用电催化剂进行表面改性可以有效地提高PEC电池的水分解效率。在此，我们研究了由Ni， Fe和Co氧化物组成的电催化剂及其混合物对Ta3N5光阳极表面改性对PEC析氧反应（OER）性能的影响。在所研究的样品中，NiFeOx修饰的Ta3N5 （NiFeOx/Ta3N5）光阳极表现出最低的OER发作电位。由NiFeOx/Ta3N5光阳极和掺杂Al的La5Ti2Cu0.9Ag0.1S5O7 （LTCA:Al）光电阴极组成的平行结构的PEC电池在没有任何外部偏置电压的情况下，可以通过水分解产生化学计量量的氢和氧。在反应开始后1 min，该电池的太阳能-氢能量转换效率（STH）为0.2%。此外，在石英绝缘衬底上制备了NiFeOx/Ta3N5透明光阳极作为前电极，LTCA:Al光电阴极作为后电极，采用串联结构的PEC电池进行了水分解，并且在反应初始阶段发现STH为0.04%。
The development of visible-light-responsive semiconductor-based photoelectrodes is a prerequisite for the construction of efficient photoelectrochemical (PEC) cells for solar water splitting. Surface modification with an electrocatalyst on the photoelectrode is effective for maximizing the water splitting efficiency of the PEC cell. Herein, we investigate the effects of surface modification of Ta3N5 photoanodes with electrocatalysts consisting of Ni, Fe, and Co oxides, and their mixture, on the PEC oxygen evolution reaction (OER) performance. Among the investigated samples, NiFeOx-modified Ta3N5 (NiFeOx/Ta3N5) photoanodes showed the lowest onset potential for OER. A PEC cell with a parallel configuration consisting of a NiFeOx/Ta3N5 photoanode and an Al-doped La5Ti2Cu0.9Ag0.1S5O7 (LTCA:Al) photocathode exhibited stoichiometric hydrogen and oxygen generation from water splitting, without any external bias voltage. The solar-to-hydrogen energy conversion efficiency (STH) of this cell for water splitting was found to be 0.2% at 1 min after the start of the reaction. In addition, water splitting by a PEC cell with a tandem configuration incorporating a NiFeOx/Ta3N5 transparent photoanode prepared on a quartz insulating substrate as a front-side electrode and a LTCA:Al photocathode as a back side electrode was demonstrated, and the STH was found to be 0.04% at the initial stage of the reaction.