Fabrication of g-C3N4/PW12/TiO2 composite with significantly enhanced photocatalytic performance under visible light

The exploration and development of supernally effective and persistent visible-light-responsive catalysts for environment remediation is regarded as one of the most challenging topics at present. Herein, a new g-C3N4/PW12/TiO2 (CN/PT-X; X = 3.2, 6 and 9) composite photocatalyst was fabricated through a convenient electrospinning/calcination technique, followed with thermal polymerization method. In the composite, the g-C3N4 was grown on PW12/TiO2 nanofibers forming 3D nanofibrous networks, in which the g-C3N4 quality was simply operated by regulating quality ratios of urea to PW12/TiO2 during preparation process. The X-ray photoelectron spectra (XPS) results confirmed the interfacial interaction between g-C3N4 and PW12/TiO2, implying the heterojunction formation between the two components. The photocatalytic tests showed that the CN/PT composites exhibited remarkable and stable photocatalytic performance for removing tetracycline (TC), bisphenol A (BPA) and reduction of Cr(VI) with visible-light (lambda > 420 nm) irradiation. Furthermore, the CN/PT-6 sample displayed the optimal catalytic activity with the rate constants of 0.03443 min(-1) (TC), 0.00712 min(-1) (BPA) and 0.025 min(-1) (Cr(VI)), respectively. The enhanced performance could be ascribed to the enhanced adsorption in visible-light region, high specific surface area, effective separation and transfer of photoinduced charge carriers. The active species capturing tests and ESR measurements verified that h(+) and center dot O-2(-) were answerable for TC degradation. The mechanism accounting for the observed photocatalytic behaviour was proposed and discussed based on the band gap structure and free radicals capture tests. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

A new g-C3N4/PW12/TiO2 composite photocatalyst was fabricated through electrospinning/calcination technique and thermal polymerization method, showing remarkable and stable photocatalytic performance under visible light irradiation. The enhanced performance can be attributed to enhanced adsorption in visible-light region, high specific surface area, and effective separation and transfer of photoinduced charge carriers.