Controlled fabrication of TiO.sub.2/C.sub.3N.sub.4 core-shell nanowire arrays: a visible-light-responsive and environmental-friendly electrode for photoelectrocatalytic degradation of bisphenol A

• Published in: Journal of materials science 2018-08, Vol.53 (15), p.11015
• Main Authors: Wang, Yajun, Wu, Qiaohuan, Li, Yan, Liu, Liming, Geng, Zhouliang, Li, Yuming, Chen, Juan
• Format: Article
• Language: English
• Subjects: Bisphenol-A; Phenols (Class of compounds)
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-018-2368-3

Photoelectrocatalytic (PEC) oxidation is a promising method in water treatment due to the synergistic effect of photocatalytic (PC) oxidation and electro-oxidation. Up to now, developing visible-light-responsive, efficient and environmental-friendly electrode for PEC degradation application is still a challenge. In this work, novel and environmental-friendly TiO.sub.2/C.sub.3N.sub.4 core-shell nanowire arrays as an electrode were investigated for PEC degradation of bisphenol A (BPA). TiO.sub.2 nanowire arrays provide a direct electron pathway, g-C.sub.3N.sub.4 serves as a stable and environmental-friendly visible light sensitizer, and effective charge spatial separation can be achieved across the well-matched core-shell interface. Compared with TiO.sub.2 nanowire arrays, TiO.sub.2/C.sub.3N.sub.4 core-shell nanowire arrays exhibit higher PC and PEC performance. The photocurrent response of the TiO.sub.2 nanowire arrays is enhanced about two times after C.sub.3N.sub.4 shell deposition. And the PEC performance of TiO.sub.2/C.sub.3N.sub.4 core-shell nanowire arrays is significantly enhanced, which is one time higher than that of TiO.sub.2 (under 1.0 V external potential). The enhancement of PEC performance of TiO.sub.2 nanowire arrays after C.sub.3N.sub.4 modification can be attributed to the synergistic photoelectric effect, well-matched interface and efficient charge separation induced by the type-II TiO.sub.2/C.sub.3N.sub.4 band alignment. Moreover, the intermediate products of BPA degradation by PEC oxidation were analyzed by gas chromatography-mass spectrometry and five specific products were identified, and then two possible pathways for BPA degradation by PEC process were proposed.