Eu(2+) and Eu(3+) Doubly Doped ZnWO(4) Nanoplates with Superior Photocatalytic Performance for Dye Degradation

Eu(2+) and Eu(3+) doubly doped ZnWO(4) nanoplates with highly exposed {100} facets were synthesized via a facile hydrothermal route in the presence of surfactant cetyltrimethyl ammonium bromide. These ZnWO(4) nanoplates were characterized using scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectrometry, diffuse UV-vis reflectance spectroscopy, photoluminescence spectrophotometry, and photoluminescence lifetime spectroscopy to determine their morphological, structural, chemical, and optical characteristics. It is found that Eu-doped ZnWO(4) nanoplates exhibit superior photo-oxidative capability to completely mineralize the methyl orange into CO(2) and H(2)O, whereas undoped ZnWO(4) nanoparticles can only cleave the organic molecules into fragments. The superior photocatalytic performance of Eu-doped ZnWO(4) nanoplates can be attributed to the cooperative effects of crystal facet engineering and defect engineering. This is a valuable report on crystal facet engineering in combination with defect engineering for the development of highly efficient photocatalysts.