The surface characteristics of nanostructures play a critical role in the applications. In this thesis, two Cu2S nanostructures synthesized via a general solution route are applied in surface enhanced Raman scattering (SERS) and photocatalytic degradation. In the first part of this thesis, we demonstrate a facile, rapid, and practical approach to fabricate a flowerlike Cu2S substrate and then decorated Ag nanoparticles with a convenient galvanic reduction method. The scanning electron microscopy (SEM) images indicate that Ag nanoparticles are preferential deposited on the edge of Cu2S sheets due to the localization of the electrons on the surface of Cu2S. Owing to the introduction of Ag nanoparticles on the surface of Cu2S structures, the resulting Ag-Cu2S composite structures could be used as a versatile substrate for surface enhanced Raman scattering. In addition, Ag nanoparticles on the semiconductor surface behave like electron sinks, which can provide sites for accumulation of the photogenerated electrons, and then facilitate the separation of electrons and holes. Hence, adding Ag nanoparticles is a promising method to enhance the photocatalytic performance of Cu2S nanosheets. It is significant that photocatalysts fabricated by Cu2S nanosheets can be applied to the degradation of organic pollution, and solves the environmental issues. ? In the second part, the Cu2S nanowires grow directly onto copper substrate by utilizing the biomolecule-assisted approach. Besides the reductive properties of biomolecules, they also have strong shape or size directing functionality in the reaction process. The field-emission properties of the Cu2S nanowires are studied by the Folwer-Nordheim (F-N) theory. The Cu2S nanowires show low turn-on field (1.19 V/μm) and high field enhancement factor (β=19381). The photocatalytic activity of two kinds of Cu2S structures was investigated by degradation of rhodamine B (RhB) under UV illumination. The experimental results indicate that surface area play a significant role on the efficiency of photocatalysis since photocatalytic reaction occurred on the surface.
