Encapsulation of CsPb2Br5 in TiO2 Microcrystals to Enhance Environmental Stability

• Published in: Micromachines (Basel) Vol. 14; no. 12; p. 2186
• Main Authors: Wang, Yuezhu, Xu, Xiaotong, Yang, Wenchao, Wei, Yawen, Wang, Junsheng
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.12.2023
• Subjects: Acids; Anatase; Charge efficiency; CsPb2Br5; Electrical resistivity; environmental stability; Functional groups; Heat treatment; Lead compounds; Ligands; Metal halides; Microcrystals; Nanocrystals; Optical properties; Optoelectronic devices; p-aminobenzoic acid; Perovskites; Photoelectricity; Stability; Temperature; TiO2; Titanium dioxide; Ultraviolet radiation; United States > US; China; Japan
• ISSN: 2072-666X; 2072-666X
• DOI: 10.3390/mi14122186

All-inorganic lead halide perovskite has emerged as an attractive semiconducting material due to its unique optoelectronic properties. However, its poor environmental stability restricts its broad application. Here, a simple method for the fabrication of CsPb2Br5/TiO2 is investigated. The introduction of p-aminobenzoic acid, which has two functional groups, is critical for the capping of amorphous TiO2 on CsPb2Br5. After calcination at 300 °C, amorphous TiO2 crystallizes into the anatase phase. The CsPb2Br5/TiO2 NCs show high long-term stability in water and enhanced stability against ultraviolet radiation and heat treatment, owing to the chemical stability of TiO2. More importantly, photo-electrochemical characterizations indicate that the formation of TiO2 shells can increase the charge separation efficiency. Hence, CsPb2Br5/TiO2 exhibits improved photoelectric activity owing to the electrical conductivity of the TiO2 in water. This study provides a new route for the fabrication of optoelectronic devices and photocatalysts based on perovskite NCs in the aqueous phase. Furthermore, the present results demonstrate that CsPb2Br5/TiO2 NCs has considerable potential to be used as a photoelectric material in optical sensing and monitoring.