A review of stabilizing systems for metal nanocatalysts, such as surfactants, complexants, polymers, SiO₂, Fe₃O₄, graphene materials, and combined components thereof.

Surface functionalization with stimuli-responsive materials can turn an ordinary material into a smart one that shows adaptive properties upon external stimuli. In this study, an electrospun regenerated cellulose (RC) nanofibrous membrane was firstly prepared; subsequently, poly(N-isopropylacrylamide) (PNIPAAm), a thermo-responsive polymer, was surface grafted to form the polymer chains/brushes on the surface of RC nanofibers via the surface-initiated atom transfer radical polymerization (SI-ATRP) method. Thereafter, the PNIPAAm-modified RC nanofibrous membrane was investigated for its temperature-responsive surface wettability at temperatures below/above the lower critical solution temperature (LCST). Furthermore, the nature of the hydrophilic/hydrophobic transitions of the modified nanofibrous membrane was also investigated through the water up-take and release experiment at various temperatures. Especially, as responses to different temperatures, the PNIPAAm-grafted nanofibrous membrane exhibits switchable super-lyophilic/super-lyophobic properties at a water–oil–solid three-phase interface. With the large surface area and switchable surface wettability, the as-prepared PNIPAAm-grafted nanofibrous membrane exhibits excellent properties of controllable oil/water separation, and possesses great potential towards both wastewater treatment and oil purification.

The synthesis and application of biomass-derived carbon in energy storage have drawn increasing research attention due to the ease of fabrication, cost-effectiveness, and sustainability of the meso/microporous carbon produced from various biological precursors, including plants, fruits, microorganisms, and animals. Compared to the artificial nanostructured carbons, such as fullerene, carbon nanotube and graphene, the biomass-derived carbons may obtain superior capacitance, rate performance and stability in supercapacitor applications ascribing to their intrinsic nanoporous and hierarchical structures. However, challenges remain in processing techniques to obtain biomass-derived carbons with high carbon yield, high energy density, and controllable graphitic microstructures, which may require a clear understanding over the chemical and elemental compositions, and the intrinsic microstructural characteristics of the biological precursors. Herein we present comprehensive analyses over the impacts of the chemical and elemental compositions of the precursors on the carbon yield of the biomass, as well as the mechanism of chemical activation on the nanoporous structure development of the biomass-derived carbons. The structure–property relationship and functional performance of various biomass-derived carbons for supercapacitor applications are also discussed in detail and compared. Finally, useful insights are also provided for the improvements of biomass-derived carbons in supercapacitor applications.