Ultra-efficient and durable photoelectrochemical water oxidation using elaborately designed hematite nanorod arrays
Ultra-efficient and durable photoelectrochemical water oxidation using elaborately designed hematite nanorod arrays
复制标题
DOI：
10.1016/j.nanoen.2017.06.049
复制
发表时间：
2017-09-01
期刊：
影响因子：
17.6
通讯作者：
Choi, Wonyong
中科院分区：
文献类型：
--
作者：
Jeon, Tae Hwa;Moon, Gun-hee;Choi, Wonyong
报道了利用改性的α-Fe 2 O3纳米棒阵列实现水的超高效光电化学氧化。赤铁矿纳米棒阵列使用化学浴沉积合成，并通过氢处理、加载类似于3.5 nm厚的TiO 2覆盖层和沉积磷酸钴（CoPi）催化剂进一步改性。尽管每种改性方法都是众所周知的，但组合改性方法的精心优化在AM 1.5G照射（100 mW cm（-2））下在1.23 V（相对于RHE）下在100 h内实现了类似于6 mA cm（-2）的稳定光电流密度，其中化学计量的O-2和H-2以类似于95%的法拉第效率产生。据我们所知，这是使用基于赤铁矿的光阳极获得的最高光电流密度，并且这种长期耐久性与这种效率水平相结合的报道很少。使用各种光谱和电化学技术的改性赤铁矿光阳极的彻底特征。虽然氢处理增强了导电性，但TiO 2覆盖层减少了表面电荷复合，并有效地保持了氢处理的赤铁矿电极的完整性。
Ultrahigh-efficiency photoelectrochemical water oxidation using modified hematite (alpha-Fe2O3) nanorod arrays is reported. The hematite nanorod arrays are synthesized using chemical bath deposition and further modified by hydrogen treatment, loading of a similar to 3.5-nm-thick TiO2 overlayer, and deposition of a cobalt phosphate (CoPi) catalyst. Although each modification method is well known, an elaborate optimization of the combined modification methods achieves a stable photocurrent density of similar to 6 mA cm(-2) at 1.23 V vs. RHE over 100 h under AM 1.5G irradiation (100 mW cm(-2)) with the stoichiometric O-2 and H-2 evolutions at similar to 95% of Faradaic efficiency. To the best of our knowledge, this is the highest photocurrent density obtained using a hematite-based photoanode, and such long-term durability coupled with this level of efficiency has been rarely reported. The modified-hematite photoanodes are thoroughly characterized using various spectroscopic and electrochemical techniques. While the hydrogen treatment enhances the electrical conductivity, the ultrathin TiO2 overlayer reduces the surface charge recombination and effectively preserved the integrity of the hydrogen-treated hematite electrode.