摘要
Localized surface plasmon resonances (LSPR) in near-infrared (NIR) region have been extensively studied for copper chalcogenide nanostructures, not only for the absorption enhancement but also tunable LSPR characteristics with their free carrier concentrations or defects. In the present work, one-step cation exchange method has been used to synthesize Cu 2−x S nanowires with x varied between 0 and 1, including Cu 2 S, Cu 7 S 4 and CuS and so forth. The plasmonic band of Cu 2−x S nanowires shifts to a shorter wavelength with the increase in x, as observed in vis-NIR spectra, which is attributed to the increase in density of copper vacancies. The Cu 2−x S nanowires have been used as catalysts towards the photocatalytic generation of H 2 from ammonia borane (AB). Among samples with different Cu-S compositions, Cu 7 S 4 samples exhibited the highest activity in terms of H 2 evolution rate (25.54 mmol/g h). Moreover, a marked enhancement of the H 2 evolution rate (157.04 mmol/g h) could be achieved after decorating the Cu 2−x S nanowires with Pd nanoparticles to form the hybrid structures. The results of the present investigation may lead to an effective strategy for the design and development of LSPR materials for photocatalytic applications.