Bingqing Liu

Bio: Bingqing Liu is an academic researcher from Northwest Normal University. The author has contributed to research in topics: Detection limit & Suspension (topology). The author has co-authored 2 publications.

Metalated covalent organic frameworks: from synthetic strategies to diverse applications.

Abstract: Covalent organic frameworks (COFs) are a class of organic crystalline porous materials discovered in the early 21st century that have become an attractive class of emerging materials due to their high crystallinity, intrinsic porosity, structural regularity, diverse functionality, design flexibility, and outstanding stability. However, many chemical and physical properties strongly depend on the presence of metal ions in materials for advanced applications, but metal-free COFs do not have these properties and are therefore excluded from such applications. Metalated COFs formed by combining COFs with metal ions, while retaining the advantages of COFs, have additional intriguing properties and applications, and have attracted considerable attention over the past decade. This review presents all aspects of metalated COFs, from synthetic strategies to various applications, in the hope of promoting the continued development of this young field.

Recent Advances in Synthesis, Modification, Characterization, and Applications of Carbon Dots

Abstract: Although there is significant progress in the research of carbon dots (CDs), some challenges such as difficulty in large-scale synthesis, complicated purification, low quantum yield, ambiguity in structure-property correlation, electronic structures, and photophysics are still major obstacles that hinder the commercial use of CDs. Recent advances in synthesis, modification, characterization, and applications of CDs are summarized in this review. We illustrate some examples to correlate process parameters, structures, compositions, properties, and performances of CDs-based materials. The advances in the synthesis approach, purification methods, and modification/doping methods for the synthesis of CDs are also presented. Moreover, some examples of the kilogram-scale fabrication of CDs are given. The properties and performance of CDs can be tuned by some synthesis parameters, such as the incubation time and precursor ratio, the laser pulse width, and the average molar mass of the polymeric precursor. Surface passivation also has a significant influence on the particle sizes of CDs. Moreover, some factors affect the properties and performance of CDs, such as the polarity-sensitive fluorescence effect and concentration-dependent multicolor luminescence, together with the size and surface states of CDs. The synchrotron near-edge X-ray absorption fine structure (NEXAFS) test has been proved to be a useful tool to explore the correlation among structural features, photophysics, and emission performance of CDs. Recent advances of CDs in bioimaging, sensing, therapy, energy, fertilizer, separation, security authentication, food packing, flame retardant, and co-catalyst for environmental remediation applications were reviewed in this article. Furthermore, the roles of CDs, doped CDs, and their composites in these applications were also demonstrated.

Biocompatible carbon quantum dots for intelligent sensing in food safety applications: Opportunities and sustainability

Abstract: Carbon quantum dots (CQDs) are widely used in various industries due to their non-toxic, biocompatibility, antibacterial, and tunable photoluminescence properties. In particular, interest in developing smart/intelligent sensing systems using CQDs is increasing in the food industry. The integration of CQDs-sensing platforms with food packaging could provide a means to allow real-time monitoring of the quality change of packaged foods. A novel fluorescent carbon nanomaterial, CQD, is considered a promising candidate for developing novel intelligent nanosensors for food quality control. Therefore, it is noteworthy to analyze new information on the proficiency of CQD-based sensing systems in developing sustainable, innovative packaging materials. Although CQDs have been used for several potential applications, the focus of the current review is to summarize recent research and developments on CQD-based sensors that can be used in the food industry. This review also outlines the potential challenges and prospects of modern CQDs and real-time intelligent sensing of food quality changes.

Preparation of carbon quantum dots using bike pollutant soot: Evaluation of structural, optical and moisture sensing properties

Abstract: Humidity sensor-based carbon quantum dots (CQDs) have been prepared using waste bike pollutant soot. The synthesized CQDs were characterized using a UV–Visible light chamber, UV–Visible spectroscopy , photoluminescence spectroscopy, TEM, and FTIR research. Initially, the sample was exposed in a closed chamber to UV–Visible light, which produced green luminescence. The photo luminescent spectrometer revealed the emission of green spectra as well as the approximate size of the CQDs. TEM and HRTEM confirmed the spherical shaped particles ∼2 nm in size. The FTIR spectra indicated the existence of a functional group. The sensing element was fabricated using the spin coating method on a borosilicate substrate and was used as a humidity sensor. Carbon quantum dots have excellent humidity sensing properties, as evidenced by measurements of sensitivity, ageing effect, repeatability, reaction, and recovery times. Many humidity sensors based on metal oxides, semiconductors, and polymers have been investigated and developed. The novelty of the work, electrical humidity sensor has been proposed using the waste pollutant soot. • The sustainable, cost effective and rapid synthesis of pollutant bike soot carbon quantum dot. • The prepared were imperiled for electrical humidity sensing. • The first, second, third and fourth layers of sensing characteristics are reported. • The beauty of the experiment is that the electrical humidity sensor is proposed to design by using the waste pollutant soot.