Significant effect on the photo conversion performance of non-stoichiometric tungsten oxide with various reaction solvents

Photothermal therapy (PTT) is a new emerging treatment method in recent years which has the advantages of non-invasive and wide adaptability. The key to PTT is the development of effective photothermal agents. Herein, the non-stoichiometric tungsten oxides were prepared in a facile solvothermal method with various reaction solvents (ethanol, n-propanol, isopropanol) and time. The obtained samples were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscope, photoluminescence and UV-vis-NIR adsorption spectroscopy. The kind of solvent had a significant effect on the phase, microstructure, photo conversion efficiency. Once n-propanol was used as solvent, the samples possessed high crystallinity, uniform fusiform morphology, good dispersibility, obvious absorbance of NIR and the photothermal conversion efficiency of 35.6%. Under the 808 nm near-infrared light irradiation, in vitro cell tests were further conducted on L929 normal and MCF-7 tumor cells for comparative experiments. The outstanding properties make the samples highly potential agents for PTT.