Enhanced Charge Transfer by Passivation Layer in 3DOM Ferroelectric Heterojunction for Water Oxidation in HCO3 - /CO2 System.
Enhanced Charge Transfer by Passivation Layer in 3DOM Ferroelectric Heterojunction for Water Oxidation in HCO3 - /CO2 System.
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DOI：
10.1002/smll.201804930
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发表时间：
2019-04
期刊：
影响因子：
13.3
通讯作者：
Zihe Cai;Yang Yan;Lin Liu;Shengxuan Lin;Xiaobing Hu
中科院分区：
文献类型：
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作者：
Zihe Cai;Yang Yan;Lin Liu;Shengxuan Lin;Xiaobing Hu
光电化学二氧化碳转化为一氧化碳、甲醇和乙烯等燃料在解决能源问题方面表现出巨大的潜力。不幸的是，由于光电阳极处的剧烈电荷复合，CO2 转换效率仍然很低。在此，通过模板辅助溶胶-凝胶方法开发了一种由 BiFeO3 和 LiNbO3 组成的新型 3D 大孔铁电异质结，旨在促进电荷转移动力学。正如预期的那样，在没有任何助催化剂的情况下，HCO3 - /CO2 体系中的光电流密度（与裸平面 BiFeO3 薄膜相比提高了 300 倍）和电荷转移效率（高达 76%）得到了极大的提高。光电化学性能可通过极化形成去极化电场来切换。光电化学阻抗谱表明，通过调节表面状态，BiFeO3 3D大孔骨架和LiNbO3钝化层的协同效应降低了电荷转移电阻。这些结果提出了一种增强光电化学水氧化作为二氧化碳还原阳极反应的新策略。
Photoelectrochemical carbon dioxide conversion to fuels such as carbon monoxide, methanol, and ethylene exhibits great potential to solve energy issues. Unfortunately, CO2 conversion efficiency is still low due to violent charge recombination at the photoanode. Herein, a novel 3D macroporous ferroelectric heterojunction composed of BiFeO3 and LiNbO3 is developed by a template-assisted sol-gel method, aiming at facilitating charge transfer kinetics. As expected, a tremendous enhancement of photocurrent density (300 times vs bare planar BiFeO3 film) and charge transfer efficiency (up to 76%) is obtained in the HCO3 - /CO2 system without any cocatalyst. The photoelectrochemical performance is switchable by poling to form a depolarization electric field. Photoelectrochemical impedance spectroscopy reveals that the charge transfer resistance decreases due to the synergistic effect of BiFeO3 3D macroporous skeleton and LiNbO3 passivation layer by tuning surface states. These results suggest a novel strategy for enhancing photoelectrochemical water oxidation as the anodic reaction of CO2 reduction.