Abstract
With the increasing awareness of environmental issues, the renewable energy production has become urgent. Hydrogen is considered to be the promising fuel for the next generation. In this work, we construct novel nano-structures for hydrogen generation. CdS-ZnO core-shell nanowires and CdS-Cu2S core-shell nanowires were synthesized. First, crystalline CdS nanowires were synthesized in a three heating zone diffusion furnace through a VLS growth method. The ZnO shell was deposited with RF sputtering, and the Cu2S shell was achieved with cation exchange method. The core-shell nanowires have been examined by scanning electron microcopy, transmission electron microcopy, X-ray diffraction and energy dispersive spectroscopy to confirm their crystal structure. Photoluminescence and UV-visible analysis were used to examine their band gap and optical properties. A Shimadzu GC-2014 was used to identify and measure the amount of hydrogen gas produced by CdS-ZnO core-shell nanowires and CdS-Cu2S core-shell nanowires. Compared to CdS nanowires, the hydrogen generating activity of CdS-ZnO and CdS-Cu2S core-shell nanowires improved more than 2 orders and 1 order in magnitude, respectively. This experiment verifies the importance and usefulness of band alignment in structure design and opens up a new path for photocatalyst for hydrogen generation.