Facile synthesis of TiO2/CNC nanocomposites for enhanced Cr(VI) photoreduction: Synergistic roles of cellulose nanocrystals

Yanxiang Li; Jinju Zhang; Chengbo Zhan; Fangong Kong; Wangliang Li; Chuanfang Yang; Benjamin S Hsiao

doi:10.1016/j.carbpol.2020.115838

Facile synthesis of TiO₂/CNC nanocomposites for enhanced Cr(VI) photoreduction: Synergistic roles of cellulose nanocrystals

Carbohydr Polym. 2020 Apr 1:233:115838. doi: 10.1016/j.carbpol.2020.115838. Epub 2020 Jan 11.

Authors

Yanxiang Li¹, Jinju Zhang¹, Chengbo Zhan², Fangong Kong³, Wangliang Li⁴, Chuanfang Yang⁵, Benjamin S Hsiao⁶

Affiliations

¹ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China.
² Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, United States.
³ Key Laboratory of Pulp and Paper Science & Technology of Ministry of Education/Shandong Province, Qilu University of Technology, Jinan, 250353, China.
⁴ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China. Electronic address: wlli@ipe.ac.cn.
⁵ CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China. Electronic address: cfyang@ipe.ac.cn.
⁶ Department of Chemistry, Stony Brook University, Stony Brook, NY 11794, United States. Electronic address: benjamin.hsiao@stonybrook.edu.

PMID: 32059891
DOI: 10.1016/j.carbpol.2020.115838

Abstract

In this study, TiO₂ nanocrystals were synthesized in the scaffold of cellulose nanocrystal (CNC) using in situ hydrolysis, where the morphology and size of TiO₂ was controlled by CNC's functional groups and surface charge. The resulting TiO₂/CNC nanocomposites showed a superior photocatalytic activity for Cr(VI) reduction under visible light (λ > 420 nm) due to the combined effects of small TiO₂ size and ligand-to-metal charge transfer (LMCT) complex between CNC and TiO₂. It was found that the charge-enriched CNC not only acted as a template to direct the crystal growth of TiO₂, but also played essential roles on light harvesting and charge transfer thereby promoting the photoreduction of Cr(VI). The demonstrated system represents a unique pathway to develop a lower cost and efficient purification material for remediation of Cr(VI).

Keywords: Cellulose nanocrystals; Cr(VI) photoreduction; Green synthesis; Ligand-to-metal charge transfer; TiO(2).