Key Laboratory of Functional Inorganic Material Chemistry, Ministry of Education of the People's Republic of China , Heilongjiang University , Harbin 150080 , P. R. China.
ACS Appl Mater Interfaces. 2019 Mar 6;11(9):9093-9101. doi: 10.1021/acsami.8b21222. Epub 2019 Feb 21.
Rational architectural design and catalyst components are beneficial to improve the photoelectrochemical (PEC) performance. Herein, hierarchical SnS/CuInS nanosheet heterostructure porous films were fabricated and decorated with C to form photocathodes for PEC water reduction. Large-size CuInS nanosheet films were first grown on transparent conducting glass to form substrate films. Then, small-size SnS nanosheets were epitaxially grown on both sides of the CuInS nanosheets to form uniform hierarchical porous laminar films. The addition of C on the surface of the SnS/CuInS porous nanosheets effectively increased visible light absorption of the composite photocathode. Photoluminescence spectroscopy and impedance spectroscopy analyses indicated that the formation of a SnS/CuInS heterojunction and decoration of C significantly increased the photocurrent density by promoting the electron-hole separation and decreasing the resistance to the transport of charge carriers. The hierarchical SnS/CuInS nanosheet heterostructure porous films containing multiscale nanosheets and pore configurations can enlarge the surface area and enhance visible light utilization. These beneficial factors make the optimized C-decorated SnS/CuInS photocathode exhibit much higher photocathodic current (4.51 mA cm at applied potential -0.45 V vs reversible hydrogen electrode ) and stability than the individual CuInS (2.58 mA cm) and SnS (1.92 mA cm) nanosheet film photocathodes. This study not only reveals the promise of C-decorated hierarchical SnS/CuInS nanosheet heterostructure porous film photocathodes for efficient solar energy harvesting and conversion but also provides rational guidelines in designing high-efficiency photoelectrodes from earth-abundant and low-cost materials allowing widely practical applications.
合理的结构设计和催化剂组分有利于提高光电化学（PEC）性能。在此，制备了分级 SnS/CuInS 纳米片异质结构多孔薄膜，并进行了 C 修饰以形成用于 PEC 水还原的光阴极。首先在透明导电玻璃上生长大尺寸的 CuInS 纳米片薄膜以形成基底薄膜。然后，在 CuInS 纳米片的两侧外延生长小尺寸的 SnS 纳米片，以形成均匀的分级多孔层状薄膜。在 SnS/CuInS 多孔纳米片表面添加 C 有效增加了复合光阴极的可见光吸收。光致发光光谱和阻抗光谱分析表明，SnS/CuInS 异质结的形成和 C 的修饰显著提高了光电流密度，这是通过促进电子-空穴分离和降低载流子输运阻力来实现的。含有多尺度纳米片和孔结构的分级 SnS/CuInS 纳米片异质结构多孔薄膜可以增大表面积并增强可见光的利用。这些有益因素使得优化的 C 修饰的 SnS/CuInS 光阴极在施加电位-0.45 V（相对于可逆氢电极）时表现出更高的光阴极电流（4.51 mA cm）和稳定性，优于单个的 CuInS（2.58 mA cm）和 SnS（1.92 mA cm）纳米片薄膜光阴极。本研究不仅揭示了 C 修饰的分级 SnS/CuInS 纳米片异质结构多孔薄膜光阴极在高效太阳能收集和转化方面的前景，还为从丰富且廉价的材料设计高效光电提供了合理的指导原则，这使得其具有广泛的实际应用。
