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High roughness has been proved to be an effective design strategy for electrocatalyst in many systems. Especially, high selectivity of carbon monoxide reduction (CORR) in competition with the hydrogen evolution reaction has been observed on high roughness electrocatalysts. However, the two well-known mechanisms, i.e., decreasing the energy barrier of CORR and increasing local pH, failed to understand the roughness-enhanced selectivity in a recent experiment. Herein we unravel the hidden mechanism by establishing a comprehensive kinetic model for CORR on catalysts with different roughness factors. We conclude that the roughness-enhanced CORR selectivity is actually kinetic controlled by local-electric-field-directed mass transfer of adsorbed species on the electrode surface. Several ways to optimize CORR selectivity are predicted. Our work highlights the kinetics in electrocatalysis on nanocatalysts, and provides a conceptually new principle for future catalyst design.

Diffusion of tracer particles in active bath has attracted extensive attention in recent years. So far, most studies have considered isotropic spherical tracer particles, while the diffusion of anisotropic particles has rarely been involved. Here we investigate the diffusion dynamics of a rigid rod tracer in a bath of active particles by using Langevin dynamics simulations in a two-dimensional space. Particular attention is paid to how the translation (rotation) diffusion coefficient \begin{document}$ D_{ \rm{T}} $\end{document} ( \begin{document}$ D_{ \rm{R}} $\end{document} ) change with the length of rod \begin{document}$ L $\end{document} and active strength \begin{document}$ F_{ \rm{a}} $\end{document} . In all cases, we find that rod exhibits superdiffusion behavior in a short time scale and returns to normal diffusion in the long time limit. Both \begin{document}$ D_{ \rm{T}} $\end{document} and \begin{document}$ D_{ \rm{R}} $\end{document} increase with \begin{document}$ F_{ \rm{a}} $\end{document} , but interestingly, a nonmonotonic dependence of \begin{document}$ D_{ \rm{T}} $\end{document} ( \begin{document}$ D_{ \rm{R}} $\end{document} ) on the rod length has been observed. We have also studied the translation-rotation coupling of rod, and interestingly, a negative translation-rotation coupling is observed, indicating that rod diffuses more slowly in the parallel direction compared to that in the perpendicular direction, a counterintuitive phenomenon that would not exist in an equilibrium counterpart system. Moreover, this anomalous (diffusion) behavior is reentrant with the increase of \begin{document}$ F_{ \rm{a}} $\end{document} , suggesting two competitive roles played by the active feature of bath particles.

Infectious microbes that spread easily in healthcare facilities remain as the severe threat for the public health, especially among immunocompromised populations. Given the intricate problem of dramatic increase in resistance to common biocides, the development of safe and efficient biocide formulated agents to alleviate drug resistance is highly demanding. In this study, Schiff-base ligands were successfully formed on natural biopolymer of epsilon-poly-L-lysine (e-PL) decorated aldehyde functionalized mesoporous silica SBA-15 (CHO-SBA-15) for the selective coordination of silver ions, which was affirmed by various physicochemical methods. Besides the identified broad-spectrum antibacterial activities, the as-prepared Schiff-base silver nanocomplex (CHO-SBA-15/e-PL/Ag, CLA-1) exhibited an improved inhibitory effect on infectious pathogen growth typified by Escherichia coli and Staphylococcus aureus in comparison with two control silver complexes without Schiff-base conjugates, SBA-15/e-PL/Ag and CHO-SBA-15/Ag, respectively. In addition, CLA-1 remarkably inhibited the growth of Mycobacterium tuberculosis due to the excellent antimicrobial activity of silver species. Significantly, CLA-1 kills Candida albicans cells, inhibits biofilm formation, and eliminates preformed biofilms, with no development of resistance during continuous serial passaging. The antifungal activity is connected to disruption of bacterial cell membranes and increased levels of intracellular reactive oxygen species. In mouse models of multidrug-resistant C. albicans infection, CLA-1 exhibited efficient in vivo fungicidal efficacy superior to two antifungal drugs, amphotericin B and fluconazole. Moreover, CLA-1 treatment induces negligible toxicity against normal tissues with safety. Therefore, this study reveals the pivotal role of the molecular design of Schiff-base silver nanocomplex formation on biopolymer surface-functionalized silica mesopores as a green and efficient nanoplatform to tackle infectious microbes.

From the organization of animal flocks to the emergence of swarming behaviors in bacterial suspension, populations of motile organisms at all scales display coherent collective motion. Recent studies showed that the anisotropic interaction between active particles plays a key role in the phase behaviors. Here we investigate the collective behaviors of based-active Janus particles that experience an anisotropic interaction of which the orientation is opposite to the direction of active force by using Langevin dynamics simulations in two dimensional space. Interestingly, the system shows emergence of collective swarming states upon increasing the total area fraction of particles, which is not observed in systems without anisotropic interaction or activity. The threshold for emergence of swarming states decreases as particle activity or interaction strength increases. We have also performed basic kinetic analysis to reproduce the essential features of the simulation results. Our results demonstrate that anisotropic interactions at the individual level are sufficient to set homogeneous active particles into stable directed motion.

The {[Sm2(FDC)2](FDC) · 10H2O}n complex, where H2FDC is a 2,5-furandicarboxylic acid, has been prepared by hydrothermal reaction and structurally characterized by X-ray single-crystal diffraction and elemental analyses. In the complex, each Sm3+ ion is nine-coordinated by four O atoms from two H2FDC ligands and five O atoms from five water molecules. Due to the crucial role of oxalate detection in food chemistry and clinical analysis, oxalate detecting properties were investigated in water by ultraviolet and visible spectroscopy. The results indicated that the complex is a potential candidate for oxalate detector in aqueous solution.

Designing high-efficiency catalyst is at the heart of a transition to future renewable energy systems. Great achievements have been made to optimize thermodynamics to reduce energetic barriers of the catalytic reactions. However, little attention has been paid to design catalysts to improve kinetics to enrich the local concentration of reactant molecules surrounding electrocatalysts. Here, we find that well-designed nanocatalysts with periodic structures can optimize kinetics to accelerate mass-transport from bulk electrolyte to the catalyst surface, leading to the enhanced catalytic performance. This achievement stems from regulation of the surface reactant flux due to the gradient of the microelectric field directing uniformly to the nearest catalyst on ordered pattern, so that all of the reactant molecules are utilized sufficiently for reactions, enabling the boost of the electrocatalytic performance. This novel concept is further confirmed in various catalytic systems and nanoassemblies, such as nanoparticles, nanorods, and nanoflakes.

Two rare earth metal complexes based on the carbon-bridged bis(phenolate) ligand, 2,2'-methylene-bis(6-tert-butyl-4-methyl-phenoxo) (LH2), have been synthesized. Reaction of LH2 with (C5H5)3Sm(THF) in a 1.5 : 1 molar ratio in THF at 50°C produced rare earth metal bis(phenolate) complex (C5H5)Sm(L)(THF)2 (I) in almost quantitative yields. Complex I reacted with 0.5 molar ratio of LH2 in toluene at 80°C afforded (L)Sm(LH)(THF)2 (II) as the final product in good yield. Reaction of LNa2 with LaCl3 in a 2 : 1 molar ratio in THF at room temperature produced hetero-nuclear rare earth metal bis(phenolate) complex (L)La(LH)(THF)2Na(THF)2 (III). In addition, II and III were characterized by X-ray single-crystal diffraction analysis (CIF file CCDC nos. 1500917 (II) and 1826699 (III)) as well as characterizations including elemental analyses and IR spectra of both complexes. Furthermore, detail reasons of the difference of structures are presented. The ionic radii of the rare earth metal plays a significant role in the structure difference of two complexes.

During the past decade, accumulating studies have been conducted on the mesoporous silica materials as the matrix of controlled drug-delivery, in which the complicated post-synthesis procedures are often involved with the molecular design to achieve the efficacy. In this study, a simplified drug delivery system of anti-cancer drug of doxorubicin (DOX) based on mesoporous SBA-15 functionalized with ferrocenecarboxylic acid (FCA) was constructed. Through a combination of physicochemical characterizations, the presence of FCA that was anchored inside the pore wall of amine groups grafted SBA-15 exhibits electron-accessible behavior without affecting the intactness of composite material. The pH-responsive release of drug molecules was achieved through the conjugation of DOX with FCA in the interior channels of mesoporous composites, which also favors the more coverage of DOX. Furthermore, the real-time cell analysis was performed to monitor the release of DOX from the mesopores and resulting cytotoxicity of cancer cell of A549 was evaluated, which results in a calculated IC50 of 43.8 μg/ml (24 h). The constructed mesoporous FCA-SBA-15 composite material provides an integrated nanoplatform to exert controlled-delivery of anti-cancer drug molecules.

We introduce a general model of biased-active particles (BAPs) with anisotropic interactions, where the direction of the active force has a nonzero biased angle from the principal orientation of the anisotropic interaction between particles, and investigate the self-assembly behaviors of a mixture of BAPs with passive particles by using Langevin dynamics simulations. Remarkably, a highly ordered superlattice consisting of small hexagonal clusters with dynamic chirality emerges within a proper range of active force, given that the biased angle is not too small. In addition, there exists an optimal level of particle activity, being dependent on the biased-angle, which is the most favorable for both the long-range order and global dynamic chirality of the system. Our results demonstrate that fascinating collective behaviors can be explored through a proper design of new active particle models.

A single-molecule-level understanding of the activity of solvating water molecules in hydrogen-bonded assemblies would provide insights into the properties of the first hydration shells. Herein, we investigate the solvation of one of the DNA bases, cytosine, whose glassy-state network formed on Au(111) contains diverse types of hydrogen-bonded dimer configurations with hierarchical strengths. Upon water exposure, a global structural transformation from interwoven chain segments to extended chains was identified by scanning tunneling microscopy and atomic force microscopy. Density functional theory calculation and coarse-grained molecular dynamics simulation indicate that water molecules selectively break the weak-hydrogen-bonded dimers at T-junctions, while the stable ones within chains remain intact. The resulting hydrated chain segments further self-assemble into molecular chains by forming strong hydrogen bonds and spontaneously releasing water molecules. Such an intriguing transformation cannot be realized by thermal annealing, indicating the dynamic nature of water molecules in the regulation of hydrogen bonds in a catalytic manner.

Configuration dynamics of flexible polymer chains is of ubiquitous importance in many biological processes. Here, we investigate a polymer chain immersed in a bath of size-changed active particles in two dimensional space using Langevin dynamics simulations. Particular attention is paid to how the radius of gyration Rg of the polymer chain depends on the size σc of active crowders. We find that Rg shows nontrivial non-monotonic dependence on σc: The chain first swells upon increasing σc, reaching a fully expanded state with maximum Rg, and then, Rg decreases until the chain collapses to a compact coil state if the crowder is large enough. Interestingly, the chain may oscillate between a collapse state and a stretched state at moderate crowder size. Analysis shows that it is the competition between two effects of active particles, one stretching the chain from inside due to persistence motion and the other compressing the chain from outside, that leads to the non-monotonic dependence. Besides, the diffusion of the polymer chain also shows nontrivial non-monotonic dependence on σc. Our results demonstrate the important interplay between particle activity and size associated with polymer configurations in active crowding environments.

We investigate configuration dynamics of a flexible polymer chain in a bath of active particles with dynamic chirality, i.e., particles rotate with a deterministic angular velocity $\omega$ besides self-propulsion,by Langevin dynamics simulations in two dimensional space. Particular attentions are paid to how the gyration radius $R_{g}$ changes with the propulsion velocity $v_{0}$,angular velocity $\omega$ and chain length. We find that in a chiral bath with a typical nonzero $\omega$, the chain first collapses into a small compact cluster and swells again with increasing $v_{0}$, in quite contrast to the case for a normal achiral bath $(\omega=0)$ wherein a flexible chain swells with increasing $v_{0}$. More interestingly, the polymer can even form a closed ring if the chain length is large enough,which may oscillate with the cluster if $v_{0}$ is large. Consequently, the gyration radius $R_{g}$ shows nontrivial non-monotonic dependences on $v_{0}$, i.e., it undergoes a minimum for relatively short chains, and two minima with a maximum in between for longer chains. Our analysis shows that such interesting phenomena are mainly due to the competition between two roles played by the chiral active bath: while the persistence motion due to particle activity tends to stretch the chain, the circular motion of the particle may lead to an effective osmotic pressure that tends to collapse the chain. In addition, the size of the circular motion $R_{0}=v_{0}/\omega$ shows an important role in that the compact clusters and closed-rings are both observed at nearly the same values of $R_{0}$ for different $\omega$.

New water soluble complex [Zn(HPDDA)2(H2O)2(4,4'-Bipy)2] n (I), where H2PDDA is pyridazine- 4,5-dicarboxylic acid, 4,4'-Bipy = 4,4'-bipyridine), has been prepared by hydrothermal reaction and structurally characterized by X-ray single-crystal diffraction analysis (CIF file CCDC no. 835525 ) and elemental analysis. In I, each Zn2+ ion is six-coordinated by two oxygen atoms from the two HPDDA ligands, two nitrogen atoms from two 4,4'-Bipy and two oxygen atoms from two water molecules. The interactions of I with calf thymus DNA were studied by circular dichroism spectroscopy. The results indicated that this water soluble zinc complex show moderate binding with DNA and could be used for candidate for therapy of cancer.

The increasing complexity of environmental pollution nowadays poses a severe threat to the public health, which attracts considerable attentions in searching for nanomaterials of multiproperty. In this study, mesoporous silica of KIT-6-encapsulated bismuth oxychloride (BiOCl), an intrinsically multifunctional material exhibiting bunched structure in the composites, are facilely prepared under hydrothermal conditions. Subsequently, the produced materials of multifunctionality were applied for photocatalysis, antibacterial test, and simultaneous determination of heavy metals including lead and cadmium. A combination of physiochemical characterizations have revealed that the BiOCl-KIT-6 composites exhibit enlarged yet refined surface morphology contributing to the improved photocatalytic ability with a band gap of 3.06 eV at a molecular ratio of 8Bi-Si. Moreover, the antibacterial activities of our BiOCl-KIT-6 composites were explored, and possible antimicrobial mechanism related to the production of reactive oxygen species was discussed. Furthermore, a sensitive electrochemical determination of heavy metals of lead and cadmium using square-wave anodic stripping voltammetry was also achieved. The composites-modified glassy carbon electrode displays a linear range of calibration curve from 0.2 to 300 μg/L with a detection limit of 0.05 μg/L (Pb2+) and 0.06 μg/L (Cd2+), respectively.

Determination of PPi levels in urine represents a measurable factor for diagnostic, treatment, and monitoring of urolithiasis. Owing to the quenching ability of Cu2+ on fluorescent carbon dots (CDs) and strong binding affinity between Cu2+ and PPi, we develop a new off–on assay for PPi detection using newly BPHA CDs (BPHA: N,N-bis(pyridin-2-ylmethyl)hexan-1-amine). The fluorescence intensity of BPHA CDs was significantly quenched by Cu2+ (“off”) through forming BPHA CDs/Cu2+ complexes and the fluorescence intensity of BPHA CDs /Cu2+ system was completely resumed by PPi (“on”) owing to the release of free Cu2+. The fluorescence turn-off/on approach showed a highly selective response to PPi over the large family of other anions. The detection limits were 0.094 μM for Cu2+ and 0.025 μM for PPi, respectively. A wide linear range for PPi was up to 4400 μM. The indicator displacement assay (IDAs) using pyrocatechol violet (PV) as a colorimetric indicator was carried out to detect PPi with the naked eyes. The “off–on” fluorescent sensor based on BPHA CDs shows many merits, including convenient operation, cost-saving, high sensitivity, selectivity, stability and wide detecting range, which is applied to PPi detection in human urine sample.

Chiral selector-functionalized magnetic nanoparticles were achieved by self-assembly anchoring L-cysteine (L-Cys) on the surface of the Au/Fe 3 O 4 nanocomposites, which was synthesized via a facile in-situ reduction process. The as-prepared L-Cys-Au/Fe 3 O 4 magnetic nanoparticles (MNPs) were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy, ultraviolet-visible spectroscopy, Fourier-transform infrared spectroscopy and electrochemical methods The typical MNPs with uniform globular morphology not only can provide the enhanced pore accessibility and excellent electrocatalytic active site for the guest species, but also effectively improve the load capacity of chiral selector of L-Cys. Based on magnetic field-induced assembly, a novel magnetic electrochemical chiral sensor (MECS) was first constructed by MNPs for the discrimination and determination of tyrosine (Tyr) enantiomers. Under the optimized experimental condition, the oxidation peak current ratio of L-Tyr to D-Tyr ( I L / I D ) and the difference between the peak potential of the two enantiomers (Δ E p = E D – E L ) was observed to be 1.85 and 84 mV according to square wave voltammetry (SWV). With the synergic effect of the magnetic Fe 3 O 4 NPs and the chiral electrocatalytic activity of L-Cys functionalized AuNPs, a linear relationship between the peak current and the concentration of the two enantiomers was obtained over the range of 1–125 μM, with the limit of detection of 0.021 μM and 0.084 μM for L- and D-Tyr, respectively. The preferential chiral recognition for L-Tyr was further verified by circular dichroism spectroscopy. Furthermore, the sensitive MECS has been successfully used for the practical determination of L- or D-enantiomer in the Tyr mixture solutions by continuously increasing the concentration of one isomer, showing the consistent and reproducible results.

The diffusion of nanoparticles immersed in semidilute polymer solutions is investigated by a hybrid mesoscopic multiparticle collision dynamics method. Effects of polymer concentration and hydrodynamic interactions among polymer monomers are focused. Extensive simulations show that the dependence of diffusion coefficient D on the polymer concentration c agrees with Phillies equation D-exp (-αcδ) with a scaling exponent δ≈0.97 which coincides with the experimental one in literature. For increasing nanoparticle size, the scaling prefactor α increases monotonically while the scaling exponent always keeps fixed. Moreover, we also study the diffusion of nanoparticle without hydrodynamic interactions and find that mobility of the nanoparticle slows down, and the scaling exponent is obviously different from the one in experiments, implying that hydrodynamic interactions play a crucial role in the diffusion of a nanoparticle in semidilute polymer solutions.

Disordered hyperuniformity, a brand new type of arrangements with novel physical properties, provides various practical applications in extensive fields. To highlight the great potential of applying disordered hyperuniformity to active systems, a practical example is reported here by an optimal sorting of dynamically chiral microswimmers in disordered hyperuniform obstacle environments in comparison with regular or disordered ones. This optimal chirality sorting stems from a competition between advantageous microswimmer-obstacle collisions and disadvantageous trapping of microswimmers by obstacles. Based on this mechanism, optimal chirality sorting is also realized by tuning other parameters including the number density of obstacles, the strength of driven force and the noise intensity. Our findings may open a new perspective on both theoretical and experimental investigations for further applications of disordered hyperuniformity in active systems., 6 pages, 5 figures

The diffusion behavior of an active Brownian particle (ABP) in polymer solutions is studied using Langevin dynamics simulations. We find that the long time diffusion coefficient D can show a non-monotonic dependence on the particle size R if the active force Fa is large enough, wherein a bigger particle would diffuse faster than a smaller one which is quite counterintuitive. By analyzing the short time dynamics in comparison to the passive one, we find that such non-trivial dependence results from the competition between persistent motion of the ABP and the length-scale dependent effective viscosity that the particle experiences in the polymer solution. We have also introduced an effective viscosity ηeff experienced by the ABP phenomenologically. Such an active ηeff is found to be larger than a passive one and strongly depends on R and Fa. In addition, we find that the dependence of D on propelling force Fa presents a good power-law scaling at a fixed R and the scaling factor changes non-monotonically with R. Such results demonstrate that the active process plays rather subtle roles in the diffusion of nano-particles in complex solutions.

New complex of Mn(C5H4N2O3)2(H2O)2·H2O (1) where C5H4N2O3 is pyridazine-5-olate-4-carboxylate (HPZOC) has been prepared by hydrothermal reaction and structurally characterized by X-ray single-cryst...

A novel magnetic molecularly imprinted sensing film (MMISF) was fabricated for the determination of estradiol (E2) based on magnetic glassy carbon electrode (MGCE) and magnetic molecularly imprinted polymers (MMIPs). The MMIPs were synthesized by in situ polymerization of glutathione (GSH)-functionalized gold (Au)-coated Fe3O4 (Fe3O4@Au-GSH) nanocomposites and aniline. The MMISF was constructed with MMIPs via a kind of "soft modification" where MMIPs were assembled and immobilized on the surface of MGCE or removed from it by freely installing a magnet into MGCE or not. The E2-MMIPs were obtained by MMIPs recognizing E2 from sample, and the electrochemical detection was carried out after forming the "soft modification" sensing film by putting MGCE into the E2-MMIPs suspension liquid. Afterwards, the "soft modification" MMISF was peeled off from the electrode by removing the magnet from MGCE. The interface of the electrode could be quickly refreshed through simple treatment for the next detection. The structures and morphologies of Fe3O4@Au-GSH, MMIPs and MMISF were investigated by Fourier transform infrared spectrometer, ultraviolet and visible spectrophotometer, scanning electron microscope and atomic force microscope. In addition, the MMISF was successfully used for detecting E2 in milk powder with good sensitivity, selectivity, reproducibility and efficiency. The linear range of the MMISF for E2 was 0.025-10.0μmolL(-1) with the limit of detection of 2.76nmolL(-1) (S/N= 3).

In this paper, a facile and one-step hydrothermal carbonization approach has been developed for the first time to synthesize β-amino alcohol functionalized fluorescent carbon dots (CDs) with L-phenylalaninol as the sole precursor source. The present CDs with β-amino alcohol moieties attached to the surface were successfully applied to fabricate a novel, simple fluorescent sensing interface for selective detection of copper ions under basic conditions based on the biuret reaction. The added copper ions, not only lead to the specific cross-linked formation of the violet complex with the two β-amino alcohol units on the surface of the CDs, but also in turn lead to the aggregation of the functionalized CDs and induce fluorescence quenching. Such fluorescence responses can be used for monitoring copper ions in the range of 0.01–100 μmol L−1 under basic conditions with the limit of detection (LOD) as low as 3.2 nmol L−1. Moreover, the proposed fluorescent sensor can resist interferences from other metal ions and can be employed for the detection of copper ions in water samples. Due to the simplicity and effectiveness, it exhibits great promise as a practical sensing platform for copper ions especially under basic conditions.

Bacterial resistance accelerated by the antibiotics misuse remains threatening for the public health propelling continuous searches for safe and economical antibacterial agents. Two-dimensional (2D) molybdenum disulfide (MoS2) holds potential in biomedical applications. In this study, MoS2 of distinct nanostructure prepared by galvanostatic electrolysis exhibited pronounced antibacterial activities and identified effect on mature biofilm disaggregation. Significantly, compared with that of nanosheets, MoS2-nanoflowers showed relatively improved antibacterial performance. When incubated with produced nanomaterials, no detectable reactive oxygen species while an apparent oxidation ability towards glutathione oxidation was identified, suggesting MoS2-nanoflowers of higher specific surface area may cause more oxidation stress to bacteria upon contact than nanosheets. The study reveals the pivotal role of modulating MoS2 surface properties using electrochemical method related to the enhanced antibacterial activity.

Formation of highly ordered structures usually needs to overcome a high free-energy barrier that is greatly beyond the ability of thermodynamic fluctuation, such that the system would be easily trapped into a state with many defects and the annealing process of which often occurs on unreachable long time-scales. Here we report a fascinating example theoretically that active core corona particles can successfully self-assemble into a large-scaled and highly ordered stripe or trimer lattice, which is hardly achieved in a non-driven equilibrium system. Besides, such an activity-induced ordered structure shows an interesting self-healing feature of defects. In addition, there exists an optimal level of activity that most favorably enhance the formation of ordered self-assembly structures. Since core corona particles act as important units for self-assembly in real practice, we believe our study opens a new design-strategy for highly ordered materials., 8 pages, 6 figures

To tackle severe environmental pollution, a search for materials by economical and eco-friendly preparations is demanding for public health. In this study, a novel in situ method to form silver nanoparticles under mild conditions was developed using biomimetic reducing agents of polydopamine coated on the rodlike mesoporous silica of SBA-15. The synthesized SBA-15/polydopamine (PDA)/Ag nanocomposites were characterized by a combination of physicochemical and electrochemical methods. 4-Nitrophenol (4-NP) and methylene blue (MB) were used as models for the evaluation of the prepared nanocatalysts of SBA-15/PDA/Ag in which the composite exhibited enhanced catalytic performance toward degrading 4-NP in solution and MB on the membrane, respectively. Additionally, compared with that of solid core-shell SiO2/PDA/Ag, tubular SBA-15/PDA/Ag showed the prolonged inhibitory effect on microbial growth as typified by Escherichia coli (60 h), Staphylococcus aureus (36 h), and Aspergillus fumigatus (60 h), which demonstrated efficient control of silver nanoparticles release from the mesopores. The constructed dual-functional SBA-15/PDA/Ag as the long-term antimicrobial agent and the catalyst of industrial products provides an integrated nanoplatform to deal with environmental concerns.

The electrocatalytic reduction reaction of carbon dioxide can be significantly enhanced by the use of sharp tip electrode. However, the experimentally observed rate enhancement is many orders of magnitudes smaller than what one would expect from an energetic point of view. Here we demonstrate that the kinetic of this tip-enhanced reaction plays a decisive role by proposing a novel reaction-diffusion kinetic model. The experimentally observed sharp-tip enhanced reaction and the maximal producing rate of carbon monoxide under different electrode potentials are well reproduced. Moreover, the optimal performance shows a strong dependence on the interaction between CO2 and the local electric field, on the adsorption rate of CO2, but not on the reaction barrier. Two new strategies to further enhance the reaction rate have also been proposed. Our findings highlight the importance of the kinetic in modeling electrocatalytic reactions.

BiOCl-SiO2 KIT-6 composite materials with raspberry-like structures are facilely prepared under hydrothermal conditions. The mesoporous siliceous support of SiO2 KIT-6-incorporated BiOCl with enlarged yet refined surface morphology characterized by physiochemical methods exhibits an improved electrochemical performance. A sensitive electrochemical detection method of cadmium concentration using square wave anodic stripping voltammetry was developed based on BiOCl-SiO2 KIT-6 composite-modified glassy carbon electrodes, which displayed wide linear ranges of 0.5 to 10 μg/L and 10 to 300 μg/L and a detection limit of 65 ng/L. The sensitive, versatile and eco-friendly sensor was successfully applied for the determination of cadmium-spiked human blood samples.