CdS decorated MnWO nanorod nanoheterostructures: a new 0D-1D hybrid system for enhanced photocatalytic hydrogen production under natural sunlight.

Constructing a heterostructure is an effective strategy to reduce the electron-hole recombination rate, which enhances photocatalytic activity. Here, we report a facile hydrothermal method to grow CdS nanoparticles on MnWO nanorods and their photocatalytic hydrogen generation under solar light. A structural study shows the decoration of hexagonal CdS nanoparticles on monoclinic MnWO. Morphological studies based on FE-TEM analysis confirm the sensitization of CdS nanoparticles (10 nm) on MnWO nanorods of diameter-35 nm with mean length ∼100 nm. The lower PL intensity of MnWO was observed with an increasing amount of CdS nanoparticles, which shows inhibition of the charge carrier recombination rate. A CdS@MnWO narrow band gap semiconductor was employed for photocatalytic hydrogen generation from water under solar light and the highest amount of hydrogen, 3218 μmol h g, is obtained which is 21 times higher than that with pristine MnWO. The enhanced photocatalytic activity is ascribed to the formation of a CdS@MnWO nanoheterostructure resulting in efficient spatial separation of photogenerated electron-hole pairs due to vacancy defects. More significantly, direct Z-scheme electron transfer from MnWO to CdS is responsible for the enhanced hydrogen evolution. This work signifies that a CdS decorated MnWO nanoheterostructure has the potential to improve the solar to direct fuel conversion efficiency.