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 H2 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 H2 evolution, and 5.62 mmol h−1 g−1 of H2 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 H2 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 H2 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. [Display omitted] •An in situ deposition route was used to prepare CuxS/TiO2 nanocomposites.•CuxS/TiO2 displayed enhanced photocatalytic H2 generation performance.•Both Cu2S and CuS facilitated the charge carriers transfer and separation.•The mechanism of enhanced photoactivity over CuxS/TiO2 was proposed.