Nanorod Array of SnO2 Quantum Dot Interspersed Multiphase TiO2 Heterojunctions with Highly Photocatalytic Water Splitting and Self-Rechargeable Battery-Like Applications

• Published in: ACS applied materials & interfaces 2019-01, Vol.11 (2), p.2071-2081
• Main Authors: Sun, Bai, Chen, Yuanzheng, Tao, Li, Zhao, Hongbin, Zhou, Guangdong, Xia, Yudong, Wang, Hongyan, Zhao, Yong
• Format: Article
• Language: English
• ISSN: 1944-8244; 1944-8252
• DOI: 10.1021/acsami.8b18884

The ever-growing demand for sustainable and renewable power sources has led to the development of novel materials for photocatalytic water splitting, but enhancing the photocatalytic efficiency remains a core problem. Herein, we report a conceptual effective and experimental confirmed strategy for SnO2 quantum dot (QD) interspersed multiphase (rutile, anatase) TiO2 nanorod arrays (SnO2/RA@TiO2 NRs) to immensely enhance the carrier separation for highly efficient water splitting by merging simultaneously the QD, multiphase, and heterojunction approaches. Under this synergistic effect, a doping ratio of 25% SnO2 QD interspersed into multiphase TiO2 NRs exhibited a superior optical adsorption and excellent photocurrent density (2.45 mA/cm2 at 1.0 V), giving rise to a largely enhanced incident light to current efficiency in the UV region (45–50%). More importantly, this material-based device can act as power supply with a voltage of ∼2.8 V after illumination, which can automatically self-recharge by reacting with oxygen vacancy and water molecule to realize reuse. The current study provides a new paradigm about heightening the carrier separation extent of QD interspersed multiphase heterojunctions, fabricating a new solar-energy-converting material/device, and achieving a highly photocatalytic water splitting/self-charging battery-like application.