Dangge Gao,Xin Bao,Bin Lyu,Zhixin Chen,Ailin Zhang,Jianzhong Ma
The growing demand for anti-counterfeiting technology has drawn attention to the emerging perovskite quantum dots (QDs). However, the poor stability of these materials is the main obstacle in their the application for reliable anti-counterfeiting. In this work, we propose an effective approach for the preparation of highly stable all-inorganic Bi-based QDs using a polyacrylate (PA) coating, achieving a photoluminescence intensity retention of 95% even after 71 h of UV irradiation. Using the leather finishing technology, PA/Cs3Bi2Br9 QDs were used as a smart concealed finishing agent to prepare fluorescent anti-counterfeiting leather. More importantly, the fluorescence effect was efficiently sustained even though the fluorescent anti-counterfeiting leather was crudely treated by water-soaking, UV light treatment, bending and rubbing treatment. This research provides effective strategies to improve the stability of Cs3Bi2Br9 QDs and a new idea for leather anti-counterfeiting applications.
Lan Ding,Yongping Ding,Fenghua Bai,Gonglai Chen,Shuwei Zhang,Xiaoxue Yang,Huiqin Li,Xiaojing Wang
Given the global warming caused by excess CO2 accumulation in the atmosphere, it is essential to reduce CO2 by capturing and converting it to chemical feedstock using solar energy. Herein, a novel Cs3Bi2Br9/bismuth-based metal–organic framework (Bi-MOF) composite was prepared via an in situ growth strategy of Cs3Bi2Br9 quantum dots (QDs) on the surface of Bi-MOF nanosheets through coshared bismuth atoms. The prepared Cs3Bi2Br9/Bi-MOF exhibits bifunctional merits for both the high capture and effective conversion of CO2, among which the optimized 3Cs3Bi2Br9/Bi-MOF sample shows a CO2–CO conversion yield as high as 572.24 μmol g–1 h–1 under the irradiation of a 300 W Xe lamp. In addition, the composite shows good stability after five recycles in humid air, and the CO2 photoreduction efficiency does not decrease significantly. The mechanistic investigation uncovers that the intimate atomic-level contact between Cs3Bi2Br9 and Bi-MOF via the coshared atoms not only improves the dispersion of Cs3Bi2Br9 QDs over Bi-MOF nanosheets but also accelerates interfacial charge transfer by forming a strong bonding linkage, which endows it with the best performance of CO2 photoreduction. Our new finding of bismuth-based metal–organic framework/lead-free halide perovskite by cosharing atoms opens a new avenue for a novel preparation strategy of the heterojunction with atomic-level contact and potential applications in capture and photocatalytic conversion of CO2.
In this work, a non-toxic bismuth-based perovskite quantum dot fluorescent nanocomposite (Cs 3 Bi 2 Br 9 @SiO 2 -MIPs) was constructed for the detection of trace oxytetracycline (OTC) in the ethanol phase, which solves the toxicity problem of perovskite quantum dots and realises the application of non-toxic perovskite quantum dots in analysis and detection, the combination boronate affinity effect and molecularly imprinted technology enables highly selective detection of the Cs 3 Bi 2 Br 9 @SiO 2 -MIPs. The basic structure and optical properties of Cs 3 Bi 2 Br 9 @SiO 2 -MIPs were characterized by various characterization methods, and the optimal detection conditions and fluorescence detection ability of Cs 3 Bi 2 Br 9 @SiO 2 -MIPs for OTC were determined. Under the optimal conditions, the Cs 3 Bi 2 Br 9 @SiO 2 -MIPs had a good linear relationship with OTC in the concentration range of 0.8 ∼ 130 μM, and the detection limit was 0.32 μM. Furthermore, the fluorescence detection mechanism of the Cs 3 Bi 2 Br 9 @SiO 2 -MIPs was investigated in detail, which ultimately revealed that the detection mechanism was a synergistic effect of inner filter effect and fluorescence resonance energy transfer. The Cs 3 Bi 2 Br 9 @SiO 2 -MIPs was successfully applied to the detection of trace OTC in real samples. This work provides a new idea for the construction of environmentally friendly and highly selective perovskite quantum dot fluorescent nanocomposite.
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