Z-scheme carbon-bridged Bi2O3/TiO2 nanotube arrays to boost photoelectrochemical detection performance

• Published in: Applied catalysis. B, Environmental Vol. 248; pp. 255 - 263
• Main Authors: Pang, Yajun, Li, Yuwei, Xu, Guangqing, Hu, Yating, Kou, Zongkui, Feng, Qiang, Lv, Jun, Zhang, Yong, Wang, John, Wu, Yucheng
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 05-07-2019; Elsevier BV
• Subjects: Bismuth oxides; Bismuth trioxide; Carbon; Carbon-bridged; Charge transfer; Conductors; Decomposition; Electromagnetic absorption; Environmental monitoring; Heterostructures; Light; Metal oxide nanocrystals; Metal oxides; Metals; Nanocrystals; Nanotubes; Organic wastes; Oxides; Photoelectric effect; Photoelectric emission; Photoelectrochemical detection; Pollution monitoring; Sensor arrays; Surface reactions; TiO2 nanotube arrays; Titanium dioxide; Water pollution; Z-scheme; TiO2 nanotube arrays; Z-scheme; Carbon-bridged; Metal oxide nanocrystals; Photoelectrochemical detection
• ISSN: 0926-3373; 1873-3883
• DOI: 10.1016/j.apcatb.2019.01.077

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•A carbon bridged Bi2O3/C@TiO2 Z-scheme system is construed.•Bi2O3 nanocrystals with uniform size of 2˜3 nm are introduced by a in situ illumination-assisted method.•The surface electrochemical reactions of TiO2 are regulated controllably.•Bi2O3/C@TiO2 NTAs exhibit a significantly improved selective photoelectrochemical determination performance for organics.
An effective photoelectrochemical sensor is urgently needed for monitoring of the environmental pollution caused by organic wastes. In this work, we report a facile in-situ illumination-assisted process to introduce uniform metal oxide (Bi2O3) nanocrystals of 2–3 nm in sizes on carbon bridged TiO2 nanotube arrays (TiO2 NTAs) (Bi2O3/C@TiO2 NTAs), in which the carbon functions as both electron trapping for high efficiency and system integration. The Bi2O3/C@TiO2 NTAs thus made exhibit a highly selective photoelectrochemical determination performance, with low background photocurrent (derived from the decomposition of water) and high detection current (derived from the decomposition of organics target). In particular, the current detection of the Bi2O3/C@TiO2 NTAs is 3.38 times higher than that of the pristine TiO2 NTAs. To understand the key working principles involved, they are scrutinized by probing into the photoelectrochemical reaction process, including the light absorption, charge separation and transfer, and surface reactions. With the novel Z-scheme heterostructure system being achieved with Bi2O3/C@TiO2 NTAs, the present work demonstrates the potential of metal oxides with uniform size in nanometer range and conductor-bridged strategy in creating Z-scheme heterostructure system with high photoelectrochemical detection performance for organics.