Fabrication mesoporous BiOCl nanocrystals decorated by WO3 nanoparticles for acceleration Visible-Illumination-Induced reduction of Hg(II)

Abstract

Herein, the synthesis of heterojunction WO3/BiOCl nanocomposites with a large surface area (195 m2 g−1) has been achieved for the first time through a simplistic synthetic procedure. The photocatalytic ability toward Hg(II) reduction was conducted under visible illumination. The obtained WO3/BiOCl nanocomposites exhibited better performance (100%) within 45 min compared with bare BiOCl, and commercial P25, particularly the 6%WO3/BiOCl nanocomposite was the highest photoreduction ability. The 6%WO3/BiOCl nanocomposite accomplished a high photoreduction rate of 1816.36 µmolg−1h−1 in comparison with the bare BiOCl ∼ 67.1 µmolg−1h−1 and P 25 ∼84.14 µmolg−1 h−1. The apparent rate constant of 6%WO3/BiOCl nanocomposite was determined at about 0.095 min−1, which promoted 41.3 and 32.7 folds higher than bare BiOCl and P25, respectively. The excellent photoreduction ability was ascribed to the promoted light-harvesting and synergistic effect for the effective separation rate of electron-hole. Through photocurrent responses and photoluminescence measurement, the possible mechanism was proposed and verified. Moreover, WO3/BiOCl photocatalyst possessed its photoreduction ability for five consecutive cycles, implying its outstanding stability. WO3/BiOCl exhibited a remarkable ability to reduce Hg(II) ions, indicating its potential in wastewater remediation. This study provides an economical and efficient avenue for the development, and recycling, of S-scheme material-based nanocomposites.