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Graphitic carbon nitride (C3N4) was hybridized by Bi2WO6 via a hydrothermal method. The high-resolution transmission electron microscopy (HR-TEM) results reveal that an intimate interface between C3N4 and Bi2WO6 forms in the heterojunctions. The UV-vis diffuse reflection spectra show that the resulting C3N4-Bi2WO6 heterojunctions possess more intensive absorption within the visible light range in comparison with pure Bi2WO6. These excellent structural and spectral properties endowed the C3N4-Bi2WO6 heterojunctions with enhanced photocatalytic activities. Significantly, the optimum photocatalytic activity of the 0.5C3N4-0.5Bi2WO6 heterojunction for the degradation of methyl orange (MO) was almost 3 and 155 times higher than those of either individual C3N4 or Bi2WO6. The possible photocatalytic mechanism with superoxide radical species as the main active species in photocatalysis is proposed on the basis of experimental results. Moreover, the heterojunction depicted high stability and durability during six successive cycles.

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Development of biosensing platforms plays a key role in research settings for identification of biomarkers and in clinical applications for diagnostics. Biosensors based on nucleic acids have taken many forms, from simple duplex-based constructs to stimuli-responsive nucleic acid nanostructures. In this review, we look at various nucleic acid-based biosensors, the different read-out strategies employed, and their use in chemical and biological sensing. We also look at current developments in DNA nanotechnology-based biosensors and how rational design of such constructs leads to more efficient biosensing platforms.

A novel graphitized porous carbon nanosphere (GPCNS) material was reported by a conveniently simultaneous activation and graphitization route, which was realized by heating resorcinol-formaldehyde (RF) resin nanospheres immersed with ZnCl 2 and FeCl 3 in an inert atmosphere. The high graphitization level was achieved through the catalytic graphitization by reduced metal Fe and the hierarchically micro/mesoporous structure was controllably produced by tuning the mass ratio of activating agent ZnCl 2 and carbon precursor. An optimal sample of GPCNS-2, which was prepared with a FeCl 3 /ZnCl 2 /RF mass ratio of 0.5:2:1, exhibiting a highly graphitized framework and uniform spherical morphology with an average diameter of ~500 nm, as well as well-interconnected micro/mesoporous structure and large surface area of 1664.8 m 2 g -1 . Behaved as an electrode material for supercapacitor application in 6 M KOH electrolyte, GPCNS-2 displayed excellently electrochemical performance with a high specific capacitance of 402.5 F g -1 at a current density of 1 A g -1 . More deeply, electrochemical impedance spectroscopy test demonstrated the low internal electrical resistance of GPCNS-2 that contributed a superior rate capability of above 75% retention ratio even at 50 A g -1 . Furthermore, GPCNS-2 electrode possessed outstanding cycling stability, and about 96% of its initial specific capacitance at 5 A g -1 was maintained after 5000 cycles.