Porous TaON Photoanodes Loaded with Cobalt-Based Cocatalysts for Efficient and Stable Water Oxidation Under Visible Light
Porous TaON Photoanodes Loaded with Cobalt-Based Cocatalysts for Efficient and Stable Water Oxidation Under Visible Light
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DOI：
10.1007/s11244-016-0548-4
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发表时间：
2016-05-01
影响因子：
3.6
通讯作者：
Abe, Ryu
中科院分区：
文献类型：
--
作者：
Higashi, Masanobu;Tomita, Osamu;Abe, Ryu
通过简单的电泳沉积的TaON颗粒，初步修饰与CoOx纳米粒子，在Ti基板上制备用于可见光诱导水氧化的多孔光阳极。后颈缩过程涉及甲醇TaCl 5溶液和随后的加热在NH3流之间形成的TaON颗粒，这有利于多孔电极内的电子传输，从而显着增加光电流。在颈缩后处理中的NH3处理的温度显著影响通过桥的电荷传输和CoOx助催化剂用于水氧化的活性，从而在723 K下加热后产生最大光电流。高度分散的CoOx纳米颗粒由于光生空穴的有效捕获和随之而来的TaON表面的自氧化失活的可能性的降低而显著提高了光电流的稳定性。磷酸盐缓冲溶液与TaON表面上的高度分散的CoOx助催化剂的组合由于原位光电化学产生的无定形钴/磷酸盐（Co-Pi）相而显著增加了光电流，所述无定形钴/磷酸盐（Co-Pi）相几乎完全覆盖TaON表面，并因此改善了其在长期光照射中的稳定性。
Porous photoanodes for visible-light-induced water oxidation were prepared via simple electrophoretic deposition of TaON particles, preliminarily modified with CoOx nanoparticles, on a Ti substrate. Post-necking process involving methanolic TaCl5 solution and subsequent heating in NH3 stream formed bridges between TaON particles, which facilitated electron transport within the porous electrode and thereby increased the photocurrent significantly. The temperature of the NH3 treatment in the post-necking process significantly influenced both the charge transport through the bridges and the activity of the CoOx cocatalyst for water oxidation, thus producing maximum photocurrent after heating at 723 K. The highly dispersed CoOx nanoparticles considerably improved the stability of the photocurrent due to efficient capture of photogenerated holes and consequent reduction of the probability of self-oxidative deactivation of the TaON surface. The combination of phosphate buffer solutions with a highly dispersed CoOx cocatalyst on the TaON surface significantly increased the photocurrent due to the in situ photoelectrochemical production of an amorphous cobalt/phosphate (Co-Pi) phase, which covers the TaON surface almost entirely, and consequently improved the its stability in long-term photoirradiation.