Modification of TiO2 Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti3+ Complex

Yang Cao; Peng Zhou; Yongguang Tu; Zheng Liu; Bo-Wei Dong; Aryan Azad; Dongge Ma; Dong Wang; Xu Zhang; Yang Yang; Shang-Da Jiang; Rui Zhu; Shaojun Guo; Fanyang Mo; Wanhong Ma

doi:10.1016/j.isci.2019.09.024

Modification of TiO₂ Nanoparticles with Organodiboron Molecules Inducing Stable Surface Ti³⁺ Complex

iScience. 2019 Oct 25:20:195-204. doi: 10.1016/j.isci.2019.09.024. Epub 2019 Sep 18.

Authors

Yang Cao¹, Peng Zhou², Yongguang Tu³, Zheng Liu⁴, Bo-Wei Dong⁴, Aryan Azad¹, Dongge Ma⁵, Dong Wang¹, Xu Zhang⁶, Yang Yang⁷, Shang-Da Jiang⁴, Rui Zhu⁸, Shaojun Guo⁹, Fanyang Mo¹⁰, Wanhong Ma¹¹

Affiliations

¹ Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, China.
² Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.
³ State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China; Shaanxi Institute of Flexible Electronics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.
⁴ Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
⁵ School of Science, Beijing Technology and Business University, Beijing 100048, China.
⁶ Department of Physics and Astronomy, California State University Northridge, Northridge, CA 91330, USA.
⁷ Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA 91125, USA.
⁸ State Key Laboratory for Artificial Microstructure and Mesoscopic Physics, School of Physics, Frontiers Science Center for Nano-optoelectronics & Collaborative Innovation Center of Quantum Matter, Peking University, Beijing 100871, China; Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China.
⁹ Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, China; Department of Materials Science and Engineering, College of Engineering, Peking University, Beijing 100871, China.
¹⁰ Department of Energy and Resources Engineering, College of Engineering, Peking University, Beijing 100871, China; Jiangsu Donghai Silicon Industry S&T Innovation Center, Donghai County, Jiangsu 222300, China. Electronic address: fmo@pku.edu.cn.
¹¹ Beijing National Laboratory for Molecular Sciences, Key Laboratory of Photochemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, The Chinese Academy of Sciences, Beijing 100190, China.

Abstract

As one of the most promising semiconductor oxide materials, titanium dioxide (TiO₂) absorbs UV light but not visible light. To address this limitation, the introduction of Ti³⁺ defects represents a common strategy to render TiO₂ visible-light responsive. Unfortunately, current hurdles in Ti³⁺ generation technologies impeded the widespread application of Ti³⁺ modified materials. Herein, we demonstrate a simple and mechanistically distinct approach to generating abundant surface-Ti³⁺ sites without leaving behind oxygen vacancy and sacrificing one-off electron donors. In particular, upon adsorption of organodiboron reagents onto TiO₂ nanoparticles, spontaneous electron injection from the diboron-bound O^2- site to adjacent Ti⁴⁺ site leads to an extremely stable blue surface Ti³⁺‒O^-· complex. Notably, this defect generation protocol is also applicable to other semiconductor oxides including ZnO, SnO₂, Nb₂O₅, and In₂O₃. Furthermore, the as-prepared photoelectronic device using this strategy affords 10³-fold higher visible light response and the fabricated perovskite solar cell shows an enhanced performance.

Keywords: Chemistry; Energy Materials; Materials Chemistry; Materials Science; Surface Chemistry.