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Pt/CeO2 catalysts with unitary Pt species, nanoparticles, clusters or single atoms, often exhibit excellent activity and unique selectivity in many catalytic reactions benefiting from their small size, abundant unsaturated active sites, and unique electronic structure. In recent years, a tremendous number of related articles have provided great inspiration to future research and development of Pt/CeO2 catalysts. In this review, the state-of-the-art evolution of Pt nanoparticles to Pt single atoms on CeO2 is reviewed with the emphasis on synthetic strategies, advanced characterization techniques (allowing one to clarify the single atoms from clusters), the catalytic applications and mechanisms from the viewpoint of theoretical calculation. Finally, the critical outlooks and the challenges faced in developing the single-atom Pt/CeO2 catalysts are highlighted.

Inspired by the delicate architecture of hyaline articular cartilage, we report on a biomimetic polymer hydrogel that incorporates strong intermolecular hydrogen bonding between urethane–urethane linkages as well as urethane–ester linkages. The resultant hydrogel, containing ≈75% water, can endure a compressive stress up to 56 MPa with a strain of 98%, and exhibit tunable compressive modulus (0.19–1.38 MPa), as well as toughness (3629–28290 J m–2) within a wide range. The tensile strength and elastic modulus reach as high as 0.56 and 5.5 MPa, respectively. The high stiffness and toughness enable the gel to withstand cyclic compressive loadings without fracturing. Moreover, our hydrogel mimics the extracellular matrices of cartilage and bone tissues and provides biochemical and physical cues that support the three-dimensional proliferation of chondrocytes and osteogenic differentiation of preosteoblasts.

Poly[4,4′-(diphenyl ether)-5,5′-bibenzimidazole] (oPBI) based high temperature proton exchange membranes are prepared by covalent cross-linking with chloromethylated polysulfone (CMPSU) and doping with zirconium phytate (ZrPA). ZrPA is synthesized as the proton conductor through a facile method from zirconyl chloride and phytic acid which is abundant and readily available. oPBI is cross-linked by CMPSU and that hydrogen bonds are formed between ZrPA and oPBI-CMPSU. The composite membranes are dense without through holes when doping with ZrPA. The composite membranes exhibit good thermal stability below 140 °C. Meanwhile, the composite membranes reveal good mechanical strength and methanol resistance. The oxidative stability is improved because of cross-linking and the doping of ZrPA. Conductivities of oPBI-CMPSU/ZrPA at different temperatures and relative humidity (RH) are investigated. At 100% RH, 50% RH and 0 RH, the conductivity of oPBI-CMPSU(20%)/ZrPA(30%) can reach 0.072 S/cm, 0.025 S/cm and 0.012 S/cm at 140 °C, respectively. Although the proton conductivity of the composite membrane was not particularly high at 100% RH, the composite membrane comparatively exhibited good proton conductivity at high temperature and at 50% RH and 0 RH.

Vacuum-drying and freeze-drying were adopted to improve the catalytic activity of Ce0.5Pr0.5O2 for soot combustion. The specific surface area and pore volume of the as-prepared Ce0.5Pr0.5O2 were greatly increased compared to the counterpart using the common drying method. Furthermore, the redox performance and the oxidation ability for soot were enhanced, as demonstrated by H2-TPR and soot-TPR. Thus, lower combustion temperatures and higher intrinsic activity were obtained. This work demonstrated that simply changing the drying process of precipitates can be served as a paradigm to improve the structure and catalytic performance.

As an emerging method for mildly molding polymer hydrogel bioscaffolds, the enzymatically polymerized system is mainly based on the screening of various oxidoreductases to produce radicals, but the design of multifunctional nanoinitiators to facilitate hydrogel performance remains challenging. Here, we utilize N-hydroxyimide-modified silica nanoparticles as nanoinitiators to simultaneously trigger glucose oxidase anaerobic polymerization and nanoparticle-grafting enhancement of the gelatin-polyacrylamide (PAAM) hydrogel. The enzyme-nanoinitiator system produced nitrogen radicals, which were further converted into carbon radicals via GOx-catalyzed glucose reduction, as confirmed by electron paramagnetic resonance (EPR) analysis. Our stretchable hydrogel has a 12-fold increased fracture energy relative to traditional hydrogel due to grafting enhancement by the nanoinitiator. The temperature-dependent physical crosslinking of gelatin endowed our hydrogel facile printing ability. Cytotoxicity assay and 3D cell culture demonstrated the low toxicity of our hydrogel. As the first example of the use of nanoinitiators for enzymatic polymerization, this work provides a biocompatible platform to prepare or print hydrogel bioscaffolds with the required mechanical strength.

Sulfur cathodes in lithium-sulfur (Li-S) batteries still suffer from their low electronic conductivity, undesired dissolution of lithium polysulfide (Li2S n , 3 ≤ n ≤ 8) species into the electrolyte, and large degree volume change during the cycle. To overcome these problems, an effective encapsulation for the sulfur cathode is necessary. By means of particle swarm optimization (PSO) and density functional theory (DFT), we have predicted a stable metallic two-dimensional sp2-hybridized carbon allotrope (DHP-graphene). This carbon sheet can prevent S atoms from cathode entering electrolyte. However, Li-ions can shuttle freely due to the increasing difference in Li-ions concentration between electrolyte and cathode along with the potential difference between cathode and anode during charge-discharge cycles. In addition, versatile electronic band structures and linear dispersion are found in DHP-graphene nanoribbons but only metallic band structure occurs for DHP-graphene nanotubes.

Waterborne viruses frequently cause disease outbreaks and existing strategies to remove such viral pathogens often involve harsh or energy‐consuming water treatment processes. Here, a simple, efficient, and environmentally friendly approach is reported to achieve highly selective disinfection of specific viruses with living engineered biofilm materials. As a proof‐of‐concept, Escherichia coli biofilm matrix protein CsgA was initially genetically fused with the influenza‐virus‐binding peptide (C5). The resultant engineered living biofilms could correspondingly capture virus particles directly from aqueous solutions, disinfecting samples to a level below the limit‐of‐detection for a qPCR‐based detection assay. By exploiting the surface‐adherence properties of biofilms, it is further shown that polypropylene filler materials colonized by the CsgA‐C5 biofilms can be utilized to disinfect river water samples with influenza titers as high as 1 × 107 PFU L−1. Additionally, a suicide gene circuit is designed and applied in the engineered strain that strictly limits the growth of bacterial, therefore providing a viable route to reduce potential risks confronted with the use of genetically modified organisms. The study thus illustrates that engineered biofilms can be harvested for the disinfection of pathogens from environmental water samples in a controlled manner and highlights the unique biology‐only properties of living substances for material applications., A simple, efficient, and environmentally friendly approach to achieve highly selective disinfection of specific viruses with living engineered biofilm materials from virus‐polluted water is reported. The engineered biofilms can disinfect influenza virus from contaminated water to a level below the limit‐of‐detection for a qPCR‐based detection assay, thus protecting mammalian cells against virus infections efficiently.