Room-temperature synthesis of CuxS (x=1 or 2) co-modified TiO2 nanocomposite and its highly efficient photocatalytic H2 production activity

TiO2 nanoparticles functionalized with CuxS (CuxS-TiO2, x =1 or 2) photocatalysts were synthesized via a facile precipitation method at room temperature. The resulting products were well characterized by XRD, TEM, EDS, XRF, BET, XPS, UV-vis and PL. The performance of H-2 production by photocatalytic water decomposition for the CuxS-TiO2 nanocomposite was examined in methanol aqueous solution using a 300 W Xe lamp as light source. Results showed that the activities of the CuS and Cu2S dual-cocatalysts co-loaded samples exhibited highly efficient water splitting capabilities for H-2 evolution, and 5.62 mmol h(-1) g(-1) of H-2 production was achieved with the composition-optimized CuxS-TiO2, which was more efficient than those of single cocatalyst deposited samples and TiO2 alone. It is proposed that the co-deposition of CuS and Cu2S onto TiO2 nanoparticle surface could efficiently extend light absorption toward visible light range, facilitate the separation of photoinduced charge carriers and consequently enhance the photocatalytic H-2 production activity. The present work not only shows the possibility for the simultaneous utilization of CuxS mixtures as efficient cocatalysts and photosensitizers to significantly facilitate the photoactivity of H-2 evolution, but also offers a general, feasible strategy for constructing ternary hybrid photocatalysts with other multivalent non-noble metal compounds as cocatalysts for target applications in solar energy conversion. (C) 2017 Elsevier B.V. All rights reserved.