【作者】 王文慧； 金灿； 齐利民；

【Author】 Wenhui Wang;Can Jin;Limin Qi;College of Chemistry and Molecular Engineering,Peking University;

【机构】 北京大学； 北京大学化学与分子工程学院；

【摘要】 面向光电化学电解水应用的半导体纳米结构光阳极材料的设计与制备引起了广泛关注[1]。硫化镉具有良好的可见光吸收能力以及较高的载流子迁移速率,是一类具有潜在应用价值的光阳极材料[2]。但是光生空穴易将S^2-氧化,对材料造成光腐蚀,并且会产生有毒的可溶性Cd²⁺,这些问题限制了CdS光阳极材料的实际应用。CdS一维纳米结构阵列有利于电子传输和电荷分离,但它对光的捕获能力有待提高。我们近期的研究表明,纳米棒@纳米碗这类阵列结构有利于太阳光的捕获和光电化学性能的提高[3]。本工作中,我们首先利用胶体球刻蚀法制备了大面积有序的SnO₂纳米碗阵列,然后通过水热方法在纳米碗中生长CdS纳米棒阵列,最终得到新颖的异质结构CdS纳米棒@SnO₂纳米碗阵列。该异质结构纳米阵列用作光电化学分解水的光阳极时,在1.23 V vs RHE处的光电流密度可达3.8 mA/cm²,是单纯CdS纳米棒阵列的2.5倍。为提高阵列的稳定性,我们利用化学修饰的方法,在CdS纳米棒表面包覆一层无定形SiO_x薄层,该氧化硅层能够避免CdS材料直接与电解质接触,避免了光生空穴对CdS的腐蚀。该研究工作为半导体光阳极材料的形貌调控以及高性能光电化学分解水光阳极的设计制备提供了新思路。更多还原

【Abstract】 There is an increasing interest in the design and synthesis of novel semiconductor nanostructures as photoelectrodes for efficient photoelectrochemical（PEC） water splitting.CdS 1 D nanoarrays have direct charge carrier transport pathways but they usually suffered from limited light harvesting.Herein,we report the design and fabrication of heterostructured CdS nanorod@SnO₂ nanobowl arrays as a new type of photoelectrochemical photoanode.CdS nanorods were directly grown on the inner surface of SnO₂ nanobowl arrays with a monolayer inverse opal structure.Under AM 1.5 G solar light irradiation,the CdS nanorod@SnO₂ nanobowl array photoanode yielded a photocurrent density of 3.8 mA/cm² at 1.23 V with respect to the reversible hydrogen electrode（RHE）,which was 2.5 times higher than that of CdS nanorods directly grown on FTO substrate（1.5 mA/cm²）.By a facile solution process,a thin layer of amorphous SiOx was coated onto the heterostructured array,which considerably improved the stability of the photoanodes.Our strategy may offer a new approach towards the controlled fabrication of semiconductor photoanodes with enhanced PEC performance.更多还原