WS 2 and C-TiO 2 Nanorods Acting as Effective Charge Separators on g-C 3 N 4 to Boost Visible-Light Activated Hydrogen Production from Seawater.

Semiconductor photocatalysis is regarded as an ideal method for use in solving the energy shortage and environmental issues by converting solar energy to chemical energy. Herein, we have designed a facile synthetic methodology to obtain a ternary co-modified g-C ₃ N ₄ composite via WS ₂ and carbon-doped TiO ₂ (C-TiO ₂ ) nanorods with highly efficient photocatalytic activity for hydrogen production from deionized (DI) water and a natural seawater system under visible-light illumination. This composite exhibits enhanced photocatalytic activity compared to the pristine g-C ₃ N ₄ , WS ₂ , C-TiO ₂ nanorods, and the reference-modified g-C ₃ N ₄ composite with individual WS ₂ or C-TiO ₂ nanorods. Co-modified g-C ₃ N ₄ composite shows a great photostability in both DI water and seawater. Under λ=420 nm monochromatic light illumination, the apparent quantum efficiency of the co-modified g-C ₃ N ₄ composite in seawater solution is 13.08 %, which is higher than pure g-C ₃ N ₄ (5.06 %). WS ₂ , TiO ₂ , and g-C ₃ N ₄ constitute a ternary heterojunction boosting the fast separation of photoinduced electron-hole pairs, which plays a crucial role in enhancing photocatalytic activity. Therefore, the WS ₂ and C-TiO ₂ nanorod co-modified g-C ₃ N ₄ composite with high photocatalytic performance provides a promising candidate for rationally utilizing the seawater resource to produce clean chemical energy.
(© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)