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A copper-based catalyst, which was supported by sulfonate group (−SO3H) grafted active carbon (AC), was prepared and activated simultaneously by liquid phase chemical reduction method. The modified copper catalyst, Cu/AC–SO3H, displayed an enhanced catalytic performance for selective hydrogenation of furfural (FAL) to furfuryl alcohol (FOL) in liquid phase, in which almost 100% FOL yield was obtained at 378 K and 0.4 MPa of hydrogen pressure after 120 min reaction. The effect of −SO3H was evaluated and illustrated by the combination of reaction performance and physicochemical characterizations, such as X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectrometer (XPS) measurements. Through grafting sulfonate group on the support, better dispersion of nanoparticles, higher reduction degree of Cu, and stronger adsorption of FAL can be attained to contribute high hydrogenation performance. In addition, the effects of reaction conditions (such as reaction temperature, H2 pressure, reaction time, solvent, and catalyst to FAL mass ratio) were evaluated intensively. Also, the Cu/AC–SO3H catalyst showed an excellent catalytic performance for transfer hydrogenation of FAL, in which 2-propanol was utilized as the solvent and hydrogen donor concurrently. Cycling test proved the prepared catalyst could be recycled and reused for several times without noticeably reduced catalytic activity of hydrogenation.

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Surface wrinkles are commonly observed in large-scale of graphene films. As a new feature, the wrinkled surface of graphene films may directly affect bacterial viability by means of various interactions of bacterial cells with graphene sheets. In the present study, we introduce a wrinkled surface geometry of graphene oxide (GO) thin films for antibacterial application. Highly wrinkled GO films were formed by vacuum filtration of a GO suspension through a prestrained filter. Several types of wrinkled GO surfaces were obtained with different roughness grades determined by root-mean-square values. Antibacterial activity of the fabricated GO films toward three different bacterial species, Escherichia coli, Mycobacterium smegmatis, and Staphylococcus aureus, was evaluated in relation to surface roughness. Because of their nanoscopically corrugated nature, the wrinkled GO films exhibited excellent antibacterial properties. On the basis of our detailed observations, we propose a novel concept of the surrounded contact-based mechanism for antimicrobial activity of wrinkled GO films. It postulates formation of a mechanically robust GO surface "trap" that prompts interaction of bacteria with the diameter-matched GO sink, which results in substantial damages to the bacterial cell membrane. We believe that our approach uncovered a novel use of a promising two-dimensional material for highly effective antibacterial treatment.

3D graphene/δ-MnO2 aerogels demonstrated high removal efficiency, fast adsorption kinetics, excellent regeneration towards heavy metal ions based on the perfect integration of surface adsorption and in-depth bulk uptake.

Bifunctional NH2-MIL-88(Fe) nanooctahedra have been successfully fabricated for highly sensitive and specific recognition as well as efficient removal of arsenate.

developing area of nanochemistry. A particularly interesting topic in this fi eld is the synthesis and properties of NPs with concave nanoscale geometries. These NPs have distinct "spiky" shapes, with apexes that give rise to multiple optical, chemical, biological effects. NPs typically have Platonic geometries, which include tetrahedrons, cubes, hexahedrons, octahedrons, dodecahedrons, and icosahedrons, representing fi ve regular tessellations of the sphere. Some examples of Archimedean and Johnson solids can also be found among NPs. [ 1-3 ] From a geometrical perspective, all shapes mentioned above are convex. Concave NPs are much less common and, while known, [ 4-9 ] their formation mechanism is still enigmatic. A large surface area, plasmonic hot spots, strong near-infrared absorbance, and special interactions with cells and cell components [ 10-27 ] differentiate concave spiky particles from NPs with spherical and/or other convex shapes. All of these properties have high practical relevance and, apart from the fundamental interest, make it possible to substantially advance NP applications in catalysis, photonics, electronics, plasmonics, sensing, biological labeling, imaging, and cancer therapy. In general, the spiky particles are thermodynamically unstable and can potentially transform into spherical particles with time. [ 28 ] The synthesis conditions for them were identifi ed serendipitously, which does negate their importance or uniqueness but rather underlines the need to understand the underlying reasons for such growth pattern seeming deviating from thermodynamic control elaborated for "smooth" particles with Platonic shapes. While many papers do not describe the mechanism of formation of the spikes and focus primarily on the unusual morphology and optical properties of corresponding dispersions, [ 17,29,30 ] the formation of the spiked or bristled particles is currently attributed to different tendency of the stabilizers exemplifi ed by thioglycolic acid, [ 31 ] poly(vinylpyrrolidone) (PVP), [ 6 ] or cetyltrimethylammonium bromide (CTAB), [ 7 ] to absorb on diverse crystal faces. [ 6,8 ] The pivotal role of surface defects on NP seeds increasing in numbers under rapid growth conditions was also suggested as potential reason for the growth of spikes. [ 7 ] These explanations involving the thermodynamically controlled variability of stabilizer density and kinetically controlled density of defects as well as the combination thereof, however,

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