A multijunction of ZnIn2S4 nanosheet/TiO2 film/Si nanowire for significant performance enhancement of water splitting

• Published in: Nano research Vol. 8; no. 11; pp. 3524 - 3534
• Main Authors: Liu, Qiong, Wu, Fangli, Cao, Fengren, Chen, Lei, Xie, Xinjian, Wang, Weichao, Tian, Wei, Li, Liang
• Format: Journal Article
• Language: English
• Published: Beijing Tsinghua University Press 01.11.2015
• Subjects: Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Carrier transport; Chemistry and Materials Science; Condensed Matter Physics; Electron transfer; Materials Science; Nanosheets; Nanotechnology; Nanowires; Performance enhancement; Quantum efficiency; Research Article; Silicon; Splitting; TiO2; Titanium dioxide; Water splitting; 光解水; 增强膜; 多结; 性能; 氧化还原电位; 硅纳米线; 载流子输运; photoelectrochemical cells; atomic layer deposition; water splitting; nanosheets; multijunction
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-015-0852-5

Photoelectrodes with a specific structure and composition have been proposed for improving the efficiency of solar water splitting. Here, a novel multijunction structure was fabricated, with Si nanowires as cores, ZnIn2S4 nanosheets as branches, and TiO2 films as sandwiched layers. This junction exhibited a superior photoelectrochemical performance with a maximum photoconversion efficiency of 0.51%, which is 795 and 64 times higher than that of a bare Si wafer and nanowires, respectively. The large enhancement was attributed to the effective electron-hole separation and fast excited carrier transport within the multijunctions resulting from their favorable energy band alignments with water redox potentials, and to the enlarged contact area for facilitating the electron transfer at the multijunction/electrolyte interface.