Rational design of α-MnO2/HT-GCN nanocomposite for effective photocatalytic degradation of ciprofloxacin and pernicious activity.

The present study is mainly concerned with the development of cost-efficient composite material utilized to produce one-dimensional manganese oxide (α-MnO2) nanoparticles coated on two-dimensional graphitic carbon nitrides (HT-GCN) as nanocomposite (α-MnO2/HT-GCN) for highly efficient CIP degradation. The α-MnO2 nanoparticles (NPs) were prepared by a simple hydrothermal technique before being decorated on HT-GCN (H denotes protonation and T represents thermal-decomposition-graphitic carbon nitride). Tauc plots were used to calculate the band gap values of the photocatalysts α-MnO2 (1.74 eV), GCN (2.84 eV), HT-GCN (2.63 eV), and α-MnO2/HT-GCN (2.31 eV). The mechanism was investigated by various scavengers, particularly isopropanol (•OH) makes a significant role in the photodegradation process. The degradation percentage for ciprofloxacin was 89.2% and the rate of reaction R2 = 0.9913. This study demonstrates a unique method for developing a heterojunction-based nanocomposite of α-MnO2/HT-GCN, which exhibit better light absorption performance.

Novel Metal-Free Fluorescent Sensor Based on Molecularly Imprinted Polymer N-CDs@MIP for Highly Selective Detection of TNP.

In this article, we designed a fluorometric sensor based on nitrogen-passivated carbon dots infused with a molecularly imprinted polymer (N-CDs@MIP) via a reverse microemulsion technique using 3-aminopropyltriethoxysilane as a functional monomer, tetraethoxysilane as a cross-linker, and 2,4,6-trinitrophenol (TNP) as a template. The synthesized probe was used for selective and sensitive detection of trace amounts of TNP. The infusion of N-CDs (QY-21.6 percent) with a molecularly imprinted polymer can increase the fluorescent sensor sensitivity to detect TNP. Removal of template molecules leads to the formation of a molecularly imprinted layer, and N-CDs@MIP fluorescence response was quenched by TNP. The developed fluorescence probe shows a fine linear range from 0.5 to 2.5 nM with a detection limit of 0.15 nM. The synthesized fluorescent probe was used to analyze TNP in regular tap and lake water samples.

Green Synthesis of Self-Passivated Fluorescent Carbon Dots Derived from Rice Bran for Degradation of Methylene Blue and Fluorescent Ink Applications.

Recently, natural products are the powerful carbon source to synthesize carbon dots (CDs) with interesting physical and chemical properties. In this present work, we report a facile hydrothermal synthesis method for preparing fluorescent carbon dots using a biogenic precursor of rice bran without any surface passivation agent. The synthetic methodology was easy, simple, environmental friendly and convenient. Structural and optical properties of the RB-CDs have been studied by UV-visible, Fourier transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Fluorescence spectra and X-ray photoelectron spectroscopy (XPS) techniques. The prepared RB-CDs exhibited green emission upon irradiation with UV light and the calculated fluorescence quantum yield (QY) was found to be 7.4%. The morphological features of the synthesized RB-CDs were characterized by High-Resolution Transmission Electron Microscopy (HR-TEM), the average size of the RB-CDs was found to be 2.96 nm. The synthesized RB-CDs were beneficially applied as a catalyst for the catalytic degradation of methylene blue (MB) dye using NaBH4 as the reducing agent in the ambient conditions. The degradation of MB dye under light illumination was 89.20% in 30 min. Further, the obtained highly fluorescent RB-CDs were efficiently utilized as a fluorescent ink for luminescent pattern printing (patterning agent) in the anti-counterfeiting applications.