Preparation and optical properties of HgWO4 nanorods by hydrothermal method coupled with ultrasonic technique

For the first time, a newly luminescent nanomaterial, monoclinic wolframite-type HgWO4 nanorods (diameter: ∼200 nm; length: ~2000 nm) are prepared by hydrothermal method together with ultrasonic technique. Fluorescent (FL) and UV–Vis results both show that for HgWO4, ultrasonic irradiation procedure will change its optical behaviors greatly. When the crystals become into nanorods, the fluorescent emitting peaks (365 and 495 nm) shift to central region, and finally form a wider one at 435 nm. Similar results of UV–visible absorption peaks are observed for these two products. FTIR spectra further characterize their structure. All above unique optical performances might result from both small sizes caused by ultrasonic irradiation procedure and involvement of incompact d10 electrons. Moreover, possible synthesis mechanisms of HgWO4 nanorods are also investigated.