Plasmonic Bi Metal Deposition and g-C3N4 Coating on Bi2WO6 Microspheres for Efficient Visible-Light Photocatalysis

A low-cost semiconductor-based photocatalyst using visible light energy has attracted increasing interest for energy generation and environmental remediation. Herein, plasmonic Bi metal was deposited in situ in g-C3N4@Bi2WO6 microspheres via a hydrothermal method. As an electron-conduction bridge, metallic Bi was inserted as the interlayer between gC(3)N(4) and the surface of Bi2WO6 microspheres to enhance visible light absorption due to the surface plasmon resonance (SPR) effect and facilitate efficient electron-carrier separation. Different characterization techniques, including XRD, SEM, TEM, UV-vis, XPS, photoluminescence, and photocurrent generation, were employed to investigate the morphology and optical properties of the as-prepared samples. The results indicated that the g-C3N4(20%)@Bi@Bi2WO6 microsphere sample exhibited an extraordinary enhanced photocatalytic activity, higher than those of the g-C3N4, Bi2WO6, and g-C3N4(20%)@Bi2WO6 samples. It implies that the heterostructured combination of g-C3N4, metallic Bi, and Bi2WO6 microspheres provided synergistic photocatalytic activity via an efficient electron transfer process. On the basis of the results, a possible photocatalytic mechanism of the as-prepared samples was proposed. The present study demonstrated the feasibility of utilizing low-cost metallic Bi as a substitute for noble metals to design a doped photocatalysis composite with enhanced photocatalytic performance.