Tuning morphology-dependent localized surface plasmon resonance in quasi-metallic tungsten oxide nanostructures for enhanced photocatalysis

Quasi-metallic tungsten oxide (W18O49) with unique surface plasmon resonance shows great promise for photocatalysis. In this work, the localized surface plasmon resonance (LSPR) of W18O49 nanostructures is tuned through morphology control to improve the performance in photocatalytic reduction of Cr(vi). Their morphology change from nanowires to nanobundles and urchin-like nanospheres results in a gradual blue shift and an intensity increase in their corresponding LSPR bands due to the decreased aspect ratio and the increased oxygen vacancy concentrations of the nanostructures. The three-dimensional finite element simulation demonstrates enhanced localized electric fields from nanowires to nanobundles and urchin-like nanospheres, confirming the experimental results. Benefiting from the blue-shifted and enhanced light extinction from the LSPR in the visible-NIR region, the urchin-like W18O49 nanospheres show enhanced photocatalytic activity in the photoreduction of Cr(vi) by 21.6% compared to the nanowires under visible-NIR light illumination. The mechanism leading to the enhanced photocatalytic performance is elucidated based on the unique electronic band structure of W18O49.

Automated summary

The performance of photocatalytic reduction of Cr(vi) is improved by tuning the localized surface plasmon resonance (LSPR) of W18O49 nanostructures through morphology control. The blue shift and intensity increase of the corresponding LSPR bands are attributed to morphology changes from nanowires to nanobundles and urchin-like nanospheres, resulting in enhanced photocatalytic activity.