3D CQDs-{001}TiO2/Ti photoelectrode with dominant {001} facets: Efficient visible-light-driven photoelectrocatalytic oxidation of organic pollutants and mechanism insight

• Published in: Applied catalysis. B, Environmental Environmental, 2020-02, Vol.261, p.118229, Article 118229
• Main Authors: Niu, Qiongyan, Gu, Xiaotong, Li, Lei, Zhang, Ya-nan, Zhao, Guohua
• Format: Article
• Language: English
• Subjects: 3D CQDs-{001}TiO2/Ti; Carbon quantum dots; Oxidation; PEC oxidation; Pollutants; Quantum dots; Radiation; Titanium dioxide; Up-conversion; Upconversion; Visible light irradiation
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.118229

[Display omitted] •The 3D CQDs-{001}TiO2/Ti photoelectrode are constructed through reasonable design.•Highly efficient removal of BPA and MO wastewater are achieved on CQDs-{001}TiO2/Ti.•The nearly 100% exposed {001} facets provide the high ηinj.•The introduction of CQDs greatly improves the ηabs and ηsep.•Enhanced PEC activity is attributed to the synergy effect between CQDs and {001} TiO2. A three dimensional (3D) carbon quantum dots (CQDs) decorated {001}TiO2/Ti photoelectrode was prepared by constructing the CQDs on the surface of {001} TiO2, which were grown in-situ on Ti-mesh structure, providing the nearly 100% exposed active {001} facets. The 3D CQDs-{001}TiO2/Ti shows high PEC oxidation activity towards the MO and BPA under visible light radiation, while the relevant removal ratios are 94.8% for BPA in 1 h and 93.6% for MO in 2 h, respectively. The enhanced PEC activity of CQDs-{001}TiO2/Ti is mainly attributed to the three improved factors (ηabs, ηsep and ηinj), which is analyzed deeply. The existence of CQDs not only improve the ηabs since its superior up-conversion performance, but also promote the higher ηsep due to enhanced hole-electron pairs’ separation. The highly exposed {001} facets are favorable for oxidation reactions to provide the increased ηinj.