Gold nanoparticles (Au NPs) are installed in situ on the surfaces of graphitic carbon nitride (g-C 3 N 4 ) based on supramolecular hydroxylatopillar[6]arene (P6). The Au NPs can be obtained via the redox reaction between HAuCl 4 and P6 without any NH 2 –NH 2 , NaBH 4 , and other reductants, where AuCl 4 – is reduced to Au 0 by the −OH groups in the presence of OH – , and the −OH groups are oxidized into −COOH. First, P6 is loaded onto the surface of g-C 3 N 4 via π–π interaction between P6 and g-C 3 N 4 , which offers a stabilized and reduced site for in situ anchoring of Au NPs. The hybrid nanomaterial Au-NPs@P6@g-C 3 N 4 exhibits higher catalytic capability than the Pd/C catalyst in 4-nitrophenol (4-NP) reduction and methylene blue degradation, which opens a new avenue for designing more efficient hybrid nanomaterials for application in catalysis, sensing, and other fields.

Covalent organic frameworks (COF), as a novel platform for the synthesis metal nanoparticles, display abundant properties of adjustable porosity, high crystallinity and large surface area. Particularly, the three-dimensional (3D)-COF is...

This article analyzes exponential synchronization for a class of Cohen-Grossberg neural networks with time-varying delays. Firstly, according to the concept of synchronization, a controlled response system is constructed, and the error system is obtained. Secondly, by establishing suitable Lyapunov functions and using inequality techniques, sufficient conditions for exponential synchronization of the error system under different controllers are provided, and the exponential convergence rate of the system is given. Finally, two examples are used to verify the effectiveness of the theoretical results.INDEX TERMS Cohen-grossberg neural network, time-varying delays, exponential synchronization, impulsive control.