Hybrid nanomaterials offer potential scope for an increasing number of novel applications when engineered to deliver usefully functional properties. Recent advancements in the design of new material products that result from interactions among different compositions at the nanoscale and microscale has led to innovative ways to fabricate and process hybrids with altered structural physicochemical properties. An example is the development of novel "lubricants" that make use of ionic liquids (ILs) and their ability to induce exploitable molecular assemblies at the IL-graphene interface. In the present study, we report the potential of graphene-IL hybrid nanomaterials for engineering applications with a focus on "lubricant" properties to reduce frictional forces to enhance tribological performance. The present contribution outlines the wear and tribological properties (friction and lubrication) of a highly viscous IL [BMIM][I] and its comparison with its nanohybrid material counterpart. Detailed structural-microstructural investigations of the nanohybrid materials were performed using X-ray diffraction and microscopic techniques employing scanning electron (SEM), transmission electron (TEM), and high resolution transmission electron (HRTEM) microscopies. A comparative study of the morphology of friction track and wear behavior was assessed by SEM and TEM. These characteristic properties within and outside the friction track were further correlated with physical and chemical interactions obtained by contact angle measurements and Raman spectroscopy and energy dispersive analysis by X-ray (EDAX).

Rational engineering and assimilation of diverse chemo‐ and biocatalytic functionalities in a single nanostructure is highly desired for efficient multistep chemical reactions but has so far remained elusive. Here, we design and synthesize multimodal catalytic nanoreactors (MCNRs) based on a mesoporous metal‐organic framework (MOF). The MCNRs consist of customizable metal nanocrystals and stably anchored enzymes in the mesopores, as well as coordinatively unsaturated cationic metal MOF nodes, all within a single nanoreactor space. The highly intimate and diverse catalytic mesoporous microenvironments and facile accessibility to the active site in the MCNR enables the cooperative and synergistic participation from different chemo‐ and biocatalytic components. This was shown by one‐pot multistep cascade reactions involving a heterogeneous catalytic nitroaldol reaction followed by a [Pd/lipase]‐catalyzed chemoenzymatic dynamic kinetic resolution to yield optically pure (>99 % ee) nitroalcohol derivatives in quantitative yields.

Conspectus The extensive research performed in the past two decades has enabled the production of a range of colloidal nanocrystals, mostly through solution-based procedures that generate and transform nanostructures in bulk-phase solutions containing precursors and surfactants. However, the understanding and control of each nanocrystal (trans)­formation step during the synthesis are still complicated because of the high complexity of this process, in which multiple diverse events such as nucleation, subsequent growth, attachment, and ripening occur simultaneously in bulk suspensions. Unlike well-established solution-based methods, solid-state reactions, which had been at the forefront of traditional inorganic materials chemistry, are quite rarely utilized in the realm of nanomaterials because of the high temperatures required for most solid-state reactions, as a result of which the clusters and NCs are prone to migrate through the bulk reaction medium and sinter together uncontrollably into large particles. We have been pursuing the “nanospace-confined approach” to explore the use of a variety of solid and hollow silica nanoparticles as either solid-state or solution-phase reaction media to carry out the syntheses and transformations of nanocrystals in a unique microenvironment, partitioning the reactants, intermediates, and transition states from the rest of the bulk reaction medium. Such nanoconfined systems have the potential not only to enable efficient and selective nanocrystal conversion chemistries but also to provide fundamental understanding pertaining to the synthetic evolution of nanostructures and transient mechanistic steps. The unique spaces with sizes of a few tens of nanometers inside nanoconfined systems offer the opportunity to observe and elucidate novel deconvoluted chemical phenomena that are impossible to investigate in bulk systems, and comprehensive understanding of nanoconfined chemistry can be implicated in explaining and controlling the macroscopic chemical behaviors. This Account describes our focused research on developing spatially confined platforms for nanocrystal syntheses and transformations, highlighting our diversity-oriented strategy, namely, the “postdecoration approach”, which results in the evolution of new nanocatalytic sites in a preformed cavity for diversifying and controlling their morphologies, number, density and combinations. We discuss key examples of the “nanoconfined solid-state conversion approach” that involve novel reactions of nanocrystals within thermally stable solid silica nanospheres to synthesize and transform complex hybrid nanocrystals with increased complexity and functionality. In addition, an enlightening discussion of the examples of nanocrystal syntheses and conversions in nanoconfined solutions inside enclosed and exposed cavities of silica nanospheres is included. Finally, the important applications of nanospace-confined systems in various fields are also briefly discussed.

Cellulose can be converted into 5‐bromomethylfurfural (BMF), a brand new biofuel or biofuel intermediate, in 80 % yield by treatment with HBr and LiBr and continuous extraction with toluene. From other carbohydrates and straw, BMF was also obtained in high yields. The mechanism of BMF formation was investigated, and the results indicate that this furfural is formed during the depolymerization of cellulose and that glucose is not an intermediate.

Artificial nanoreactors that can facilitate catalysis in living systems on-demand with the aid of a remotely operable and biocompatible energy source are needed to leverage the chemical diversity and expediency of advanced chemical synthesis in biology and medicine. Here, we designed and synthesized plasmonically integrated nanoreactors (PINERs) with highly tunable structure and NIR-light-induced synergistic function for efficiently promoting unnatural catalytic reactions inside living cells. We devised a synthetic approach toward PINERs by investigating the crucial role of metal-tannin coordination polymer nanofilmthe pH-induced decomplexation-mediated phase-transition processfor growing arrays of Au-nanospheroid-units, constructing a plasmonic corona around the proximal and reactant-accessible silica-compartmentalized catalytic nanospace. Owing to the extensive plasmonic coupling effect, PINERs show strong and tunable optical absorption in the visible to NIR range, ultrabright plasmonic light scattering, controllable thermoplasmonic effect, and remarkable catalysis; and, upon internalization by living cells, PINERs are highly biocompatible and demonstrate dark-field microscpy-based bioimaging features. Empowered with the synergy between plasmonic and catalytic effects and reactant/product transport, facilitated by the NIR-irradiation, PINERs can perform intracellular catalytic reactions with dramatically accelerated rates and efficiently synthesize chemically activated fluorescence-probes inside living cells.