Design of few-layer carbon nitride/BiFeO3 composites for efficient organic pollutant photodegradation.

Heterojunction-driven photocatalysis can degrade various organic pollutants, and developing carbon nitride-based composite photocatalysts is of great significance and gains growing interest. In this study, a two-dimensional graphitic carbon nitride nanosheets/BiFeO3 (GCNNs/BiFeO3) Z-scheme heterojunction has been synthesized through the electrostatic spinning and post-calcination The obtained GCNNs/BiFeO3 nanofibers show large surface contact between GCNNs the and BiFeO3 nanostructures. The Z-scheme heterojunction shows a remarkably enhanced photocatalytic performance, which could degrade 94% of tetracycline (TC) and 88% of Rhodamine B (RhB) under LED visible light irradiation in 150 min. Radical trapping experiments demonstrate the effective construction of Z-scheme heterojunctions, and •O2- and h+ are the main active species in the photocatalytic degradation process. This study realizes a novel nanostructured GCNNs/BiFeO3 heterojunction for photodegradation applications, which would guide the design of next-generation efficient photocatalysts.

Metal-Organic Framework Assembled on Oriented Nanofiber Arrays for Field-Effect Transistor and Gas Sensor-Based Applications.

Metal-organic framework (MOF) films are essential for numerous sensor and device applications. However, metal-organic framework materials have poor machinability due to their predominant powder-like nature, and their presence as the active layer in a device can seriously affect the performance and utility of the device. Herein, active layers of field-effect transistor (FETs) devices and chemiresistor gas sensors with high performance were constructed by loading Cu3(HITP)2 (HITP = 2,3,6,7,10,11-hexaiminotriphenylene) in situ-axial anchoring on oriented nanofiber arrays prepared via electrospinning. The strong interaction between polar groups on the polymer chains and metal ions promotes the nucleation of Cu3(HITP)2, steric hindrance makes particles of Cu3(HITP)2 with uniform size, morphology, and good crystallinity during nucleation by liquid phase epitaxial growth (LPE). Influences of differently-oriented Cu3(HITP)2 NFAs-based FETs on the electrical properties were studied, optimally oriented Cu3(HITP)2 NFAs-based FETs showed good mobility of 5.09 cm2/V·s and on/off ratio of 9.6 × 103. Moreover, excellent gas sensing response characteristics were exhibited in sensing volatile organic compounds (VOCs). Chemiresistor gas sensors with high response value, faster response and recovery are widely suited for VOCs. It brings new inspirations for the design and utilization of electrically conductive MOFs as an active layer for FETs and sensor units for chemiresistor gas sensors.

Preparation of polyacrylic-acid/palygorskite composite particles via inverse-suspension polymerization for efficient separation of Ce3+ from aqueous solution.

A novel granular composite adsorbent made from palygorskite (PGS) and polyacrylic acid (PAA) (PAA@PGS) was prepared successfully by inverse-suspension polymerization. Acrylic acid (AA) molecules present in the PGS pores form PAA chains passing through the PGS channels after in situ polymerization, and bond to each other through hydrogen bonds. PAA@PGS was characterized by X-ray diffraction (XRD), Thermogravimetric Analysis (TG/TGA), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). Ce3+ was selected as a model to conduct the adsorption experiment, and the adsorption capacity reached 350 mg/g (initial concentration 500 mg/L, pH 6.0, 303.15 K). PAA@PGS performs well in the presence of interfering ions Na+ and has a high adsorption rate for about one hour. Moreover, PAA@PGS shows an excellent reusability, in the five cycle experiments, all the desorption rates are more than 95%, and when the fifth cycle time was completed, the adsorption capacity could still reach 87.20%.