Preparation and Photocatalytic Performance of Double-Shelled Hollow W₁₈O₄₉@C₃N₄@Ti₃C₂ Microspheres

Abstract

C₃N₄, C₃N₄@Ti₃C₂ and W₁₈O₄₉@C₃N₄@Ti₃C₂ hollow spheres were successfully prepared by using SiO₂ template followed by gradual deposition method. The degradation of phenol solution and photolysis ability were tested to characterize its photocatalytic activity. Compared with the single-shelled C₃N₄ and C₃N₄@Ti₃C₂ hollow spheres, double-shelled W₁₈O₄₉@C₃N₄@Ti₃C₂ hollow spheres possessed larger surface area and fast charge separation efficiency, exhibiting about 8.9 times and 4.0 times higher H₂ evolution than those of C₃N₄, C₃N₄@Ti₃C₂ hollow spheres, respectively. The photocatalytic mechanism of the W₁₈O₄₉@C₃N₄@Ti₃C₂ hollow spheres were carefully investigated according to the results of morphology design and photoelectric performance. A Z scheme mechanism based on the construction of heterojunctions was proposed to explain the improvement of photocatalytic performance. This new charge transfer mechanism appears to greatly inhibit the recombination of electrons/holes during the charge transfer process, while maintaining its strong hydrogen reduction ability, resulting in a higher photocatalytic performance.

Keywords

W₁₈O₄₉@C₃N₄@Ti₃C₂ composite / double-shelled hollow structure / preparation and characterization / photocatalytic H₂ evolution