Mussel-inspired polydopamine (PDA) deposition offers a promising route to fabricate multifunctional coatings for various materials. However, PDA deposition is generally a time-consuming process, and PDA coatings are unstable in acidic and alkaline media, as well as in polar organic solvents. We report a strategy to realize the rapid deposition of PDA by using CuSO4/H2O2 as a trigger. Compared to the conventional processes, our strategy shows the fastest deposition rate reported to date, and the PDA coatings exhibit high uniformity and enhanced stability. Furthermore, the PDA-coated porous membranes have excellent hydrophilicity, anti-oxidant properties, and antibacterial performance. This work demonstrates a useful method for the environmentally friendly, cost-effective, and time-saving fabrication of PDA coatings.

This feature article describes the multiple interfaces in the breath figure (BF) method toward functional honeycomb films with ordered pores. If a drop of polymer solution in a volatile solvent such as carbon disulphide is placed in a humid environment, evaporative cooling leads to self-assembled arrays of condensed water droplets. After evaporation of the solvent and water, patterned pores can be formed. During this BF process, the interfaces between the solution and the substrate, the solution and water droplets, and the film surface and air play extremely important roles in determining both the structures and functions of the honeycomb films. Progress in the BF method is reviewed by emphasizing the roles of the interfacial interactions. The applications of hierarchical and functional honeycomb films in separation, biocatalysis, biosensing, templating, stimuli-responsive surfaces and adhesive surfaces are also discussed.

The interface between metal catalyst and support plays a critical role in heterogeneous catalysis. An epitaxial interface is generally considered to be rigid, and tuning its intrinsic microstructure with atomic precision during catalytic reactions is challenging. Using aberration-corrected environmental transmission electron microscopy, we studied the interface between gold (Au) and a titanium dioxide (TiO2) support. Direct atomic-scale observations showed an unexpected dependence of the atomic structure of the Au-TiO2 interface with the epitaxial rotation of gold nanoparticles on a TiO2 surface during carbon monoxide (CO) oxidation. Taking advantage of the reversible and controllable rotation, we achieved in situ manipulation of the active Au-TiO2 interface by changing gas and temperature. This result suggests that real-time design of the catalytic interface in operating conditions may be possible.

Imaging a reaction taking place at the molecular level could provide direct information for understanding the catalytic reaction mechanism. We used in situ environmental transmission electron microscopy and a nanocrystalline anatase titanium dioxide (001) surface with (1 × 4) reconstruction as a catalyst, which provided highly ordered four-coordinated titanium “active rows” to realize real-time monitoring of water molecules dissociating and reacting on the catalyst surface. The twin-protrusion configuration of adsorbed water was observed. During the water–gas shift reaction, dynamic changes in these structures were visualized on these active rows at the molecular level.

Mussel-inspired polydopamine (PDA) deposition offers ap romising route to fabricate multifunctional coatings for various materials.H owever,P DA deposition is generally at ime-consuming process,a nd PDAc oatings are unstable in acidic and alkaline media, as well as in polar organic solvents. We report astrategy to realize the rapid deposition of PDAby using CuSO 4 /H 2 O 2 as atrigger.Compared to the conventional processes,o ur strategy shows the fastest deposition rate reported to date,and the PDAcoatings exhibit high uniformity and enhanced stability.F urthermore,t he PDA-coated porous membranes have excellent hydrophilicity,anti-oxidant properties,a nd antibacterial performance.T his work demonstrates auseful method for the environmentally friendly,cost-effective, and time-saving fabrication of PDAc oatings.

Preventing sintering of supported nanocatalysts is an important issue in nanocatalysis. A feasible way is to choose a suitable support. However, whether the metal–support interactions promote or prevent the sintering has not been fully identified. Now, completely different sintering behaviors of Au nanoparticles on distinct anatase TiO2 surfaces have been determined by in situ TEM. The full in situ sintering processes of Au nanoparticles were visualized on TiO2 (101) surface, which coupled the Ostwald ripening and particle migration coalescence. In contrast, no sintering of Au on TiO2 anatase (001) surface was observed under the same conditions. This facet‐dependent sintering mechanism is fully explained by the density function theory calculations. This work not only offers direct evidence of the important role of supports in the sintering process, but also provides insightful information for the design of sintering‐resistant nanocatalysts.

We report the synthesis and characterization of a series of hydroxyl-end-functionalized polystyrenes (PS-OH) and the formation of patterned porous films. The polymers were synthesized by chain end reaction of polystyrene having a bromide end group (PS-Br) with hydramines including ethanolamine, diethanol amine, 2-amino-1,3-propanediol, and 2-(2-aminoethoxy) ethanol. The polymers were characterized by gel permeation chromatography (GPC), nuclear magnetic resonance (NMR), matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and differential scanning calorimetry (DSC). It was found that the end groups can influence the glass transition temperature (T(g)) of the polystyrenes. The polymers with different end groups were then used to prepare honeycomb-patterned porous films by the breath figure method. Results reveal that the subtle chain-end modification leads to a dramatic change in the morphology of the films. Honeycomb films with large area ordered structure can be easily prepared from PS-OH. Effects of the end groups as well as blending PS-OH with PS-Br on the surface pore diameter, pore center distance, and the hierarchical structure were studied in detail. As supported by the results of polymer hydrophilicity, in situ observation of the film formation process, as well as the chain mobility, the film structure is supposed to be mainly determined by the precipitation of polystyrene at the solution/water droplet interface and the interfacial activity enhanced by the end groups.

The strong metal-support interaction (SMSI) is widely used in supported metal catalysts and extensive studies have been performed to understand it. Although considerable progress has been achieved, the surface structure of the support, as an important influencing factor,isusually ignored. We report af acet-dependent SMSI of Pd-TiO 2 in oxygen by using in situ atmospheric pressure TEM. Pd NPs supported on TiO 2 ( 101) and (100) surfaces showed encapsulation. In contrast, no such cover layer was observed in Pd-TiO 2 (001) catalyst under the same conditions.This facet-dependent SMSI, which originates from the variable surface structure of the support, was demonstrated in ap robe reaction of methane combustion catalyzedb yP d-TiO 2 .O ur discovery of the oxidative facet-dependent SMSI gives direct evidence of the important role of the support surface structure in SMSI and provides anew way to tune the interaction between metal NPs and the support as well as catalytic activity.