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Nature has provided a lot of important inspirations for human beings to create artificial methods to mimic the excellent performance of biological systems. Based on the shark skin pattern microstructure, the low surface energy and stimuli-responsive behavior of the poly(2-perfluorooctylethyl methacrylate) (PFMA) brush, a biomimetic PDMS film with superhydrophobic, self-healing and drag reduction properties was prepared by first replication of shark skin surface on PDMS film, followed by treatment with surface-initiated atom transfer radical polymerization (SI-ATRP) of FMA. The PFMA brushes can self-assemble into different hierarchical structures in ethanol or DMF, which make the biomimetic PDMS films show different contact angles. Having been damaged by finger-wipe with and without water respectively, the water repellency of the biomimetic PDMS films decreased. However, the surfaces recovered superhydrophobic property just by immersing the destroyed PDMS films into DMF which is good solvent for PFMA. The SEM images and XPS results demonstrated the changes of structure and chemical compositions of the biomimetic PDMS films surface in damage and self-healing processes. Rotational viscometer result showed the drag reduction rate of the biomimetic PDMS films surface can reach up to 21.7%. This research is expected to supply a novel method of controlling polymer brushes’ self-assembly to prepare superhydrophobic and self-healing films.

The problem with metal–organic frameworks (MOFs) as CO2-epoxide cycloaddition catalysts is the ambiguous catalytic sites. No system can precisely modify the structures and thus optimize the catalytic performance. Reticular chemistry is recognized as an efficient approach to systematically control the chemical and structural features as well as the properties of porous, crystalline materials. In this work, a Zn-phosphonocarboxylate framework (ZnPC-2) was employed as a prototype structure to investigate the structure–property relationship (SPR). ZnPC-2 is a porous rutile-type framework constructed by 6-connected Zn3(PO3)2(CO2)4 secondary building unit (Zn3-SBU) and tritopic 5-phosphonobenzene-1,3-dicarboxylic acid (H4pbdc). ZnPC-2 showed the ability to catalyze the CO2 cycloaddition reactions and Zn3-SBU was proved as efficient catalytic site. Guided by reticular chemistry, a series of iso-reticular frameworks, including Hpyr@ZnPC-2 (Hpyr = protonated pyrrolidine, Hpyr is fixed by hydrogen bonding interactions to participate the channel into segments); MZnPC-2 (M = Mg, Mn, Fe, Co, Cu; Zn(II) atoms on Zn3-SBU were partially replaced by M) and ZnPC-2-im (im = imidazole, im coordinates to the apical Zn(II) on Zn3-SBU), were designed and successfully synthesized to explore the precise active site. The catalytic performances over these iso-structures together with density functional theory calculations revealed that the dynamical transformation of the apical Zn (II) on Zn3-SBU from tetrahedral geometry to five coordinated model played the pivotal role during the catalytic process.

The electrochemical nitrogen reduction reaction (eNRR) provides a sustainable way to generate ammonia (NH3) but its Faradaic efficiency (FE) is relatively low and could be further improved, especially on the highly active molybdenum carbide (Mo2C) electrocatalyst. Our theoretical calculations suggest that unlike substitute doping model, interstitial Fe doping into Mo2C is highly eNRR-selective due to decreasing hydrogen evolution activity and unique surface-hydrogenation mechanism on negatively charged Mo sites around Fe atoms. Inspired by this prediction, we successfully developed a novel interstitial Fe doped Mo2C electrocatalyst by the pyrolysis of Fe-doped Mo/Zn bimetallic imidazolate frameworks (Fe-Mo/Zn BIFs) as a precursor where Fe atoms substitute Zn sites to obtain the spatial confinement effect. When evaluated in eNRR catalysis, Fe/Mo2C catalyst therefore exhibits a much higher FE of 20.1% at −0.45 V vs. RHE (reversible hydrogen electrode), which is almost double that of pristine Mo2C and substitute type. Moreover, the Fe/Mo2C catalyst also exhibits high ammonia yield rate with excellent durability over the six continuous cycles.

In situ chemical oxidation can be used to remediate soils contaminated with polycyclic aromatic hydrocarbons (PAHs). However, typical oxidation systems are limited by the acidic environment needed for Fenton reactions, cost and soil effects of activated persulfate, and large pores required for ozone or selected oxidation by permanganate. Chlorine dioxide (ClO2) is an environmentally friendly strong oxidant that is highly reactive with PAHs and produces limited halogenated byproducts. In this study, the kinetics, products, and mechanisms of PAH degradation in industrial soil using ClO2 were investigated. The degradation rate was approximately 84.24% for 0.90 mol kg−1 of ClO2; it increased with ClO2 concentration and temperature had little effect. The degradation process was divided into quick ( 70% of the PAHs were degraded at a typical soil pH of 5.0–7.0. Chemical pretreatment is favorable for PAH removal during ClO2 oxidation and the degradation rate was passively correlated with the desorbing fraction of the PAHs in the soil. Quenching experiments indicated that HOCl was the most important active species responsible for degradation. Among five representative PAH congeners, the degradation products of anthracene, phenanthrene, and benzo[a]pyrene were all oxygenated products. However, the degradation product of pyrene was the Cl substitution product and fluoranthene oxidation produced ring rupture oxygenated transformation and Cl substitution products. The mechanisms of PAH degradation by ClO2 oxidation include one-electron transfer, HOCl as a second oxidant, and •OH participation.

We demonstrate the synthesis of antibacterial carbon quantum dots (CQDs) through a one-step pyrolysis of biogenic polyamine (PA) and dopamine (DA) mixture. SPM/DA-CQDs synthesized from DA combined with spermine (SPM) exhibit effective antibacterial activity and high adhesion properties on glass and surfaces of polymeric contact lens material. The antimicrobial activity of SPM/DA-CQDs is primarily due to their ability to disrupt the bacterial membrane, and they possess wide spectrum antimicrobial activity against Gram-negative bacteria (Escherichia coli, Salmonella enterica serovar Enteritidis, and Pseudomonas aeruginosa) and Gram-positive bacteria (Staphylococcus aureus and its multidrug-resistant strain, methicillin-resistant S. aureus). The minimal inhibitory concentration (MIC) of SPM/DA-CQDs against the tested bacteria was >17-fold and >7-fold lower than those of CQDs prepared solely from spermine and dopamine, respectively. The great biocompatibility of our SPM/DA-CQDs is revealed from the in vitro cytotoxicity and hemolysis assays and in vivo evaluation of morphological and physiological changes of rabbit corneas. We further prepared SPM/DA-CQDs-coated coverslips and contact lenses, which display excellent stability and antibiofilm properties. Moreover, in vivo tests show that SPM/DA-CQDs suppress bacterial keratitis (BK) formation in a corneal-injured rabbit model. Our results indicate that SPM/DA-CQDs have great potential as a coating material for inhibition of biofilm formation on contact lenses, and broadly to protect medical devices from contamination.