Carbothermal Reduction Induced Ti3+ Self‐Doped TiO2/GQD Nanohybrids for High‐Performance Visible Light Photocatalysis. Issue 17 (21st February 2018)

• Record Type: Journal Article
• Authors: Tang, Jialin; Liu, Yousong; Hu, Yingjie; Lv, Guoqing; Yang, Chengtao; Yang, Guangcheng
• Is Part Of: Chemistry. Volume 24:Issue 17(2018)
• Page Start: 4390
• Page End: 4398
• Publication Date: 2018-02-21
• Subjects: carbothermal reduction -- graphene -- nanohybrids -- quantum dots -- titanium; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201705637
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: A facile calcination method is developed for the in situ synthesis of nanohybrids of Ti 3+ self‐doped TiO2 /graphene quantum dot nanosheets (Ti 3+ ‐TiO2 /GQD NSs). Ti 3+ sites are formed on the surface of the TiO2 nanosheets through carbothermal reduction by GQDs, using citric acid as a carbon source. Such heterojunctions exhibit enhanced visible‐light absorption properties, large photocurrent current densities, and low recombination of photoinduced carriers. The methylene blue (MB) and rhodamine B (RhB) photodegradation result demonstrates a higher visible‐light photocatalysis performance than that of the original TiO2 . On one hand, inducing Ti 3+ sites is efficient for the separation of photogenerated charge carriers and for reducing electron–hole pair recombination. On the other hand, GQDs are beneficial for generating more photocurrent carriers and facilitating the charge transfer across the TiO2 surface. It is proposed that Ti 3+ sites and GQDs induced in TiO2 nanosheets have a synergistic effect, leading to excellent photocatalysis properties. Finally, a theoretical calculation is provided of the carbothermal reduction for the formation mechanism of the Ti 3+ defect sites. Abstract : Heterojunctions for photocatalysis : Ti 3+ self‐doped TiO2 /graphene quantum dot (Ti 3+ ‐TiO2 /GQDs) heterojunctions are formed at 450 °C under a N2 atmosphere (see figure). The GQDs act as the reduction agents in the nanohybrids and lead directly to the formation of Ti 3+ sites. Theoretical calculations and experimental results show the synergistic effect of the Ti 3+ /Ov defect sites and GQDs for enhanced photocatalytic performance.