Photothermal Conversion of WO with a Tunable Oxidation State.

WO with a tunable oxidation state was prepared by addition of NaNO or NaBH as a redox agent in the solvothermal system. The addition of redox agents has no influence on the crystallization of WO. The obtained WO structures keep their morphology as a bundle of nanowires with a regular hexagonal on the cross-section. WO exhibits strong valence-dependent absorption features in the near-IR region. Reduced WO with more W has a higher concentration of oxygen vacancies, which enhances the localized surface plasmon resonance effect. Reduced WO exhibits a high photothermal conversion efficiency of 59.6 % and has good photothermal stability.