In search of a recyclable catalyst with synergistic adsorption and photocatalysis, unique composite photocatalysts of flower-like bismuth tungstate (Bi2WO6) and carbon nanospheres (CSs) were composited using a hydrothermal synthesis method (named CSs-Bi2WO6). Notably, based on the high visible light utilization and a reasonable band gap (2.53 eV), CSs-Bi2WO6 have good photocatalytic properties. For example, the composite with an optimized ratio (2% CSs-Bi2WO6) showed good adsorption and photocatalytic performance. Under simulated natural light conditions, the degradation rate of tetracycline (TC) by 2% CSs-Bi2WO6 was 84.6% in 60 min, which is nearly 25% higher than pure Bi2WO6. After five cycles, the observed barely decreased TC degradation rate of 2% CSs-Bi2WO6 confirmed the high cyclability and reproducibility of the photocatalyst. The total organic carbon estimation of the post-degradation reaction medium corresponded to 68.2% mineralization. Furthermore, we determined the photocatalytic reaction path by LC–MS, which confirmed that the composite catalyst could effectively degrade TC molecules into small molecules. It can be concluded that the catalyst has a broad application prospect in the field of wastewater treatment. Carbon-doped Bi2WO6 composite catalyst was used to degrade TC in wastewater efficiently. 

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Carbon-doped flower-like Bi2WO6 decorated carbon nanosphere nanocomposites with enhanced visible light photocatalytic degradation of tetracycline

Carbon dots (CDs) that simultaneously exhibit full-color and wide-range lifetime-tunable room-temperature phosphorescence (RTP) are of particular interest for potential applications in encryption and information security. However, achieving such CDs remains a great challenge thus far. This work reports on the development of a straightforward host–guest approach, where a metal–organic framework (MOF) host acts as an RTP activator of fluorescent CDs, with the RTP color dependent on the fluorescent component. The developed CDs@MOF composites exhibited RTP with a tunable emission wavelength from blue (478 nm) to red (631 nm), while the lifetime was tunable from 85.67 to 1064.21 ms. As far as is known, this is the report of CD-based RTP materials with simultaneous full-color and wide-range lifetime-tunable properties for the first time. In comparison to conventional 3D coding applications of CDs, the wide-range lifetime-tunable property allows for the creation of an additional dimension in encryption. Thus, the developed RTP CDs@MOF composites have potential as writable security inks for advanced 4D coding applications. This study paves a path for development of RTP CD-based nanomaterials with multiple controllable factors to meet the requirements of advanced applications. 

Metal–Organic Framework-Activated Full-Color Room-Temperature Phosphorescent Carbon Dots with a Wide Range of Tunable Lifetimes for 4D Coding Applications

In search of a recyclable catalyst with synergistic adsorption and photocatalysis, unique composite photocatalysts of flower-like bismuth tungstate (Bi2WO6) and carbon nanospheres (CSs) were composited using a hydrothermal synthesis method (named CSs-Bi2WO6). Notably, based on the high visible light utilization and a reasonable band gap (2.53 eV), CSs-Bi2WO6 have good photocatalytic properties. For example, the composite with an optimized ratio (2% CSs-Bi2WO6) showed good adsorption and photocatalytic performance. Under simulated natural light conditions, the degradation rate of tetracycline (TC) by 2% CSs-Bi2WO6 was 84.6% in 60 min, which is nearly 25% higher than pure Bi2WO6. After five cycles, the observed barely decreased TC degradation rate of 2% CSs-Bi2WO6 confirmed the high cyclability and reproducibility of the photocatalyst. The total organic carbon estimation of the post-degradation reaction medium corresponded to 68.2% mineralization. Furthermore, we determined the photocatalytic reaction path by LC–MS, which confirmed that the composite catalyst could effectively degrade TC molecules into small molecules. It can be concluded that the catalyst has a broad application prospect in the field of wastewater treatment. Carbon-doped Bi2WO6 composite catalyst was used to degrade TC in wastewater efficiently 

https://www.researchsquare.com/article/rs-2009614/latest.pdf

Rational synthesis of silane-functionalized carbon dots with high-efficiency full-color solid-state fluorescence for light emitting diodes

Environmentally friendly gelatin-based ink with durability on low surface energy substrates for anti-counterfeiting printing

Sensing performance and mechanism of carbon dots encapsulated into metal–organic frameworks

Construction of carbon dots modified Cl-doped Bi2WO6 hollow microspheres for boosting photocatalytic degradation of tetracycline under visible light irradiation

Solid-state carbon dots (SCDs) have been widely investigated by scholars owing to their stability, environmental friendliness, and their good optical properties. The current studies on carbon dots (CDs) are mainly focused on the solutions of CDs, while the researches on SCDs are relatively few in comparison. Nowadays, the fabrication and design of high-performance SCDs have attracted much interest. However, due to resonance energy transfer and π-π interactions, CDs undergo aggregation-induced quenching (ACQ) phenomena. This poses an obstacle to the acquisition of SCDs and affects their luminescence performance. Publications of the past 5 years are reviewed on how to suppress the ACQ phenomenon and improve the fluorescence and phosphorescence emission of CDs (Ref. 87) and about the mechanism of achieving the luminescence of SCDs. Then, the applications of SCDs in the fields of luminescent devices, anti-counterfeiting, and detection are outlined. The concluding section analyzes the current challenges faced by SCDs and provides an outlook. Mechanism of photoluminescence from solid state carbon dots

Yao Wang

Papers

Sensing performance and mechanism of carbon dots encapsulated into metal–organic frameworks

Construction of carbon dots modified Cl-doped Bi2WO6 hollow microspheres for boosting photocatalytic degradation of tetracycline under visible light irradiation

Self-quenching-resistant solid-state carbon dots for mechanism and applications

Solid-state carbon dots with orange phosphorescence and tunable fluorescence via in-situ growth in phthalimide crystal matrix

Advances in Integrating Carbon Dots With Membranes and Their Applications