Ultrathin CoOx nanolayers derived from polyoxometalate for enhanced photoelectrochemical performance of hematite photoanodes
Ultrathin CoOx nanolayers derived from polyoxometalate for enhanced photoelectrochemical performance of hematite photoanodes
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源自多金属氧酸盐的超薄 CoOx 纳米层可增强赤铁矿光电阳极的光电化学性能
DOI：
10.1039/c8ta12330f
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发表时间：
2019-03-21
影响因子：
11.9
通讯作者：
Ding, Yong
中科院分区：
文献类型：
--
作者：
Cao, Xiaohu;Wang, Yifan;Ding, Yong
分子析氧催化剂，特别是多金属氧酸盐（pom），很少被报道用于改善半导体光阳极的性能。本文研究了co基POM对Fe2O3光阳极的改性。Fe2O3的光生载流子对Co8POM有重要影响。通过简单的光沉积法制备了Co8POM超薄CoOx覆盖层，证实其为真正的活性物质。该CoOx纳米层有效抑制了赤铁矿纳米棒的表面状态，降低了水氧化过电位。与原始Fe2O3光阳极和简单钴盐制备的CoOx(POM)/Fe2O3光阳极相比，我们的cox (POM)/Fe2O3复合光阳极具有最佳的PEC性能和最高的光电压。CoOx(POM)/Fe2O3光阳极的光电流密度是原始Fe2O3光阳极的2.2倍。同时，CoOx(POM)/Fe2O3复合光阳极实现了更快的瞬态光响应，电荷注入效率提高了80%。
Molecular oxygen evolution catalysts, particularly polyoxometalates (POMs), have been rarely reported for improving the performance of semiconductor photoanodes. Herein, a Co-based POM was investigated for modifying Fe2O3 photoanodes. The photogenerated carriers of Fe2O3 have a fundamental effect on Co8POM. Ultrathin CoOx overlayer derived from Co8POM is confirmed as the true active species, which was prepared by a simple photodeposition method. This CoOx nanolayer effectively restrains the surface states on the hematite nanorod and reduces the water oxidation overpotential. Our CoOx(POM)/Fe2O3 composite photoanode affords the best PEC performance and the highest photovoltage when compared with pristine Fe2O3 photoanode and CoOx(salt)/Fe2O3 photoanode prepared by a simple cobalt salt. The photocurrent density of CoOx(POM)/Fe2O3 photoanode is 2.2 times higher than that of pristine Fe2O3 photoanodes. Meanwhile, the CoOx(POM)/Fe2O3 composite photoanode achieves faster transient photoresponse and an improved charge injection efficiency of 80%.