A simple yet efficient visible-light-driven CdS nanowires-carbon nanotube 1D-1D nanocomposite photocatalyst

One-dimensional CdS nanowires-carbon nanotubes nanocomposites (1D-1D CdS NWs-CNT NCs) with different weight addition ratios of CNT have been synthesized by a very simple room temperature self-assembly method, which is afforded by electrostatic attractive interaction between positively charged CdS NWs and negatively charged CNT in an aqueous solution. Importantly, the CdS NWs-CNT NCs exhibit remarkably enhanced photoactivity toward selective reduction of aromatic nitro organics in water under visible light irradiation as compared to bare CdS NWs. The significantly enhanced photoactivity is attributed to the integrated factors of the unique 1D-1D morphology associated with CdS NWs and CNT, the efficient retardation of recombination of the photoexcited electron-hole pairs, and the enhanced visible light absorption intensity. Besides, the CdS NWs-CNT NCs exhibit higher photoactivity than CdS NWs-reduced graphene oxide (CdS NWs-RGO NCs), toward selective reduction of aromatic nitro organics. Therefore, this work not only offers a very simple room temperature approach to synthesize highly efficient ID semiconductor-ID CNT composite photocatalyst, but also gives an example that RGO cannot readily manifest its unique and prominent advantage over CNT for specific photocatalytic application, thus underpinning the importance of rationally utilizing the carbon materials (e.g., ID CNT, 20 RGO) to design more efficient carbon-semiconductor composite photocatalyst. (C) 2013 Elsevier Inc. All rights reserved.