Plasmonic oxygen-deficient sodium tungsten bronze NayWO3-x microstructures for SERS detection

Nonmetal plasmonic semiconductors have attracted increasing research interests for the low cost and promising surface plasmon properties. Here, oxygen-deficient sodium tungsten bronze NayWO3-x microstructures on tungsten foil has been facilely fabricated, showing nonmetal plasmonic behavior and surface-enhanced Raman scattering (SERS) detection potential. The NayWO3 was firstly grown on tungsten sheets with Na doping in the solvothermal processing. Then, the oxygen vacancies have been introduced with thermal treatment in a hydrogen-containing atmosphere, resulting in NayWO3-x microstructures which revealed a localized surface plasmon resonance band at 620 nm. The NayWO3-x microstructures was used as SERS substrate for detecting methylene blue of 10-7 M, showing application potentials of plasmonic nonmetal materials.