Rational Design and Synthesis of ZnWO₄ Nanorods Decorated with SnS Nanodots with Enhanced Visible-Light Photocatalytic Performance

Aiming to construct a direct Z-scheme binary heterostructure for efficient degradation of the organic dye Rhodamine B (RhB), ZnWO4 nanorods decorated with SnS nanodots were rationally designed and prepared via a facile two-step route. Morphological observation and structural study showed that ultra-fine SnS nanodots were anchored on the surface of ZnWO4 nanorods to form an intimate contact between the two components. Such a special structure provided SnS/ZnWO4 nanocomposites with significantly enhanced light harvesting capacity, revealed by the results of UV-vis diffuse reflection spectroscopy (DRS). Photoluminescence (PL) analysis in combination with electrochemical measurements demonstrated that the recombination of photoactivated charge carriers was efficiently inhibited and the transfer of photoactivated charge carriers was successfully achieved due to the introduction of SnS. The degradation rate over SnS/ZnWO4 nanocomposites reached a maximum value at SnS content of 9 wt%. The significantly enhanced photoactivity of SnS/ZnWO4 nanocomposites was imputed to the synergistic effect of the promoted light absorption ability and effective photogenerated charge carriers’ transfer and separation