Multifunctional molybdenum oxide for solar-driven water evaporation and charged dyes adsorption

Significant efforts have been made to seek technologies to resolve water shortages. Among these efforts, seawater desalination and wastewater purification are considered mainstream strategies. Photothermal materials and adsorbents are the main components of solar-driven seawater desalination and wastewater purification, respectively. Herein, we propose MoO3-x (0 < x < 1) as a multifunctional material applied simultaneously to solar-driven seawater desalination and wastewater purification. Thanks to the oxygen vacancies (OVs)-induced localized surface plasmon resonance (LSPR) and 3D nanoflower-like superstructures, the resultant MoO3-x possesses a high total absorption of 97% over the whole solar spectrum and a high water evaporation rate of 1.51 kg m−2 h−1 as well as an calculated energy conversion efficiency of 95% under one-sun irradiation. At the same time, MoO3-x exhibits a remarkably high removal ratio of 96.1% and a high adsorption capacity of 295.0 mg g−1 for positively charged organic dyes with a fast speed (~5 min), which is ascribed to the surface functional groups generated by OVs. Finally, the photocatalytic properties of MoO3-x can be further utilized to recycle with green solar energy. The high photothermal conversion efficiency of the material combined with its excellent adsorption properties and good photocatalytic activity opens up exciting possibilities in energy and environmental applications.