Synthesis of TiO_2-x/W₁₈O₄₉hollow double-shell and core-shell microspheres for CO₂photoreduction under visible light

TiO2-x/W(18)O(49)with core-shell or double-shelled hollow microspheres were synthesized through a facile multi-step solvothermal method. The formation of the hollow microspheres with a double-shell was a result of the Kirkendall effect during the solvothermal treatment with concentrated NaOH. The advanced architecture significantly enhanced the electronic properties of TiO2-x/W18O49, improving by more than 30 times the CO(2)photoreduction efficiency compared to the pristine W18O49.OperandoDRIFTS measurements revealed that the yellow TiO(2-x)was a preferable CO(2)adsorption and conversion site.