Graphene oxide–cellulose acetate (GO–CA) nanocomposite membranes have been successfully prepared via phase inversion method. The GO sheets were firstly well dispersed in formamide, and then the solution was mixed with acetone containing CA so as to confirm the GO sheets well dispersed in the final GO–CA nanocomposite membranes. All the GO–CA nanocomposite membranes are composed of dense skin layer and sponge-like sublayer. With the increase in GO contents (from 0 to 0.01 wt%), the skin layer gradually became thinner and the pore size in the sublayer increased; meanwhile, the contact angle of GO–CA membranes decreased from 70.59° to 53.42° due to better hydrophilicity. All the membranes, except for the nanocomposite membrane containing 0.01 wt% GO, have featured pores at about 0.9 nm. The permeation rate of the membrane containing 0.005 wt% GO was 2.3 times higher than that of the CA membrane (0 wt% GO) with a little decrease (~15%) in salt retention. Compared with CA membrane, the enhanced performance of GO–CA membranes may be attributed to their enhanced structure and hydrophilicity.

The anisotropy of nanocrystals and surface functional groups play an important role in their photo-absorption as well as opto-electronic properties. In this manuscript, we report on the synthesis of cluster-like and cubic FeS2 nanocrystals via a simple colloidal chemistry method. As-prepared FeS2 nanocrystals exhibit an enhanced absorption in the light range of 400–1200 nm due to the free carrier induced localized surface plasmon resonances (LSPRs). Compared to nanoclusters, FeS2 nanocubes show a stronger absorption at longer wavelength with larger scattering effect. The surface of as-synthesized FeS2 nanocrystals has been further modified via post-synthetic ligand exchange to remove the insulating long organic hydrocarbon molecules. An obvious red shift of corresponding LSPRs frequency of FeS2 nanocrystals is observed, indicating the decrease of free carrier concentration. High quality FeS2 thin films with thickness of ~500 nm have been spray-painted from colloidal nanocrystal suspensions. The photoresponse activity has been investigated with a structure of FTO/FeS2 thin film/FTO both in the dark and under illumination using a solar simulator (AM 1.5 G irradiation, 100 mW cm−2). The photocurrent of FeS2 nanocubes is almost two times higher than that of nanoclusters, which is in accordance with stronger light absorption of FeS2 nanocubes from UV-Vis-NIR absorption spectra. After ligand exchange, an enhancement of photocurrent has been observed for cluster-like and cubic FeS2 thin films by 136.8 and 125.7% at 1000 mV, respectively. FeS2 nanocrystals with tunable LSPRs and enhanced photocurrent are attractive for applications in low-cost thin film photovoltics.

In this work, hierarchical lead sulfide (PbS) nano-architectures were obtained via a simple one-pot hydrothermal method using a single-source precursor of Pb(II)–thiourea complex, without involving any insulating organic surfactants. Structurally, the eight-armed hierarchical PbS nanostructures were controlled to exhibit one-fold, two-fold, or three-fold hierarchy of anisotropic growth along 〈111〉 directions, under different reaction conditions. The product morphology and structural evolution in the hydrothermal process exhibit four stages: Stage 1, the nucleation of PbS nanoparticles from the complex precursor; Stage 2, the formation of cubic PbS growth bases; Stage 3, the formation of PbS nano-architectures from consumption of the previously formed PbS growth bases; and Stage 4, the deconstruction of the hierarchical PbS nanoarchitectures. Nanostructures with high energy crystal faces are attractive for designing high efficiency solar cell devices. Within the PbS octa-armed dendrites, all sub-units grow along the 〈111〉 directions with {100} facets exposed. The photoexcited electrons can be driven in the {100} facets with mixed Pb/S atoms through σ bonding consisting of the overlapping s(Pb 6s)–p(S 3p) orbitals, which significantly shortens the carrier transfer distance and reduces the carrier recombination. Drop-cast thin films prepared with octa-armed PbS dendrites, showing desired [100] structural orientation, exhibit greatly enhanced photocurrent compared to that of spray-printed thin films without any structural orientation. It is expected that these findings will be useful in understanding the formation and application of PbS and other fcc nanocrystals with different morphologies.

•Sandwich-structured Si nanoparticles-Graphene nanocomposites were fabricated.•The method combines magnesiothermic reduction, freeze-drying, and thermal reduction.•The nanocomposite shows a 746 mAh g−1 reversible capacity after 160 cycles.•The nanocomposite’s specific capacity is superior to that of graphite and pure Si.•This novel method provides a low-cost alternative to prepare Si-based anodes.A novel method was developed to synthesize ordered sandwich-structured magnesiothermo-reduced Si nanoparticles (MR-Si NPs)-thermally reduced graphene oxide (TRGO) nanocomposites that combines magnesiothermic reduction, freeze-drying, and thermal reduction. The MR-Si NPs were dispersed into ordered graphene oxide (GO) layers with the aid of sonication. This MR-Si@TRGO composite structure was retained by freeze-drying and followed by thermal reduction. The key features of the nanocomposites, including nanoparticle crystal phase, size, and dispersity on the TRGO matrix, could be controlled by tuning reaction conditions such as reduction temperature and duration. The influence of the weight ratio of active materials: conductive agent: binder, the types of binder, and the content of electrolytes on the electrochemical performance as an anode in lithium-ion batteries was systematically investigated. The electrode fabricated using the MR-Si@TRGO nanocomposites under optimized conditions (80:10:10 for the weight ratio of MR-Si@TRGO: acetylene black: CMC; the electrolyte containing 5 v% vinylene carbonate) exhibited a reversible capacity of 746 mAh g−1 after 160 cycles at 1000 mA g−1, which is substantially higher than 701 mAh g−1 after 120 cycles for the MR-Si@TRGO in the absence of vinylene carbonate, 330 mAh g−1 for commercial graphite reported, and 10 mAh g−1 for pure MR-Si NPs tested at 200 mA g−1 with a weight ratio of 50:30:20 optimized for active materials: acetylene black: PVDF.

We describe a novel strategy for fabrication of a unique minky-dot-fabric-shaped composite of well-organized porous TiO2 microspheres and reduced-graphene-oxide (rGO) sheets used as an anode material in lithium-ion batteries. In this composite, the porous TiO2 microspheres act as hosts for fast and efficient lithium storage while the rGO sheets serve as highly conductive substrates. Such unique structural features assure a large contact area between the electrolyte and the electrode, favorable for the diffusion of electrons and Li+ ions. Moreover, they can accommodate volume changes of the electroactive TiO2 materials readily so as to improve the overall electrical conductivity between the electrodes during electrochemical processes. In electrochemical tests, the TiO2–rGO composites used as anodes in lithium-ion batteries exhibited superior performance with a reversible capacity of 100 mA h g−1 at 10 C for up to 100 cycles, as compared to 58 mA h g−1 at 10 C for up to 100 cycles from pure TiO2, suggesting great potential of this unique composite to function as high-rate lithium-ion battery materials.

•Porous inorganic silica foams with tunable structures and properties.•Low-temperature hydrothermal ion-exchange reaction.•Green chemistry route to porous foams.Porous inorganic silica foams are synthesized from waste ordinary glasses using a facile green chemistry route that involves a low-temperature hydrothermal ion-exchange reaction. The first step entails hydrothermal incorporation of water molecules and hydrogen ions within glass powders. Subsequent calcination of the product results in inorganic foams of uniform pore structure, with water vapor being the only by-product. The structure and properties of the inorganic foams, such as pore structure, pore size, density, porosity, strength, and thermal conductivity can be tuned by varying synthetic conditions such as reaction time and temperature. The synthesized inorganic foams are thermally stable up to 800 °C with widely tunable porous structures on different length scales. The inorganic foams exhibit useful properties in terms of mechanical strength, thermal insulation and sound absorption, and appear promising for use as catalyst supports, impact absorbers, biomedical implants, and structural materials.

We describe a novel strategy for fabrication of a unique minky-dot-fabric-shaped composite of well-organized porous TiO2 microspheres and reduced-graphene-oxide (rGO) sheets used as an anode material in lithium-ion batteries. In this composite, the porous TiO2 microspheres act as hosts for fast and efficient lithium storage while the rGO sheets serve as highly conductive substrates. Such unique structural features assure a large contact area between the electrolyte and the electrode, favorable for the diffusion of electrons and Li+ ions. Moreover, they can accommodate volume changes of the electroactive TiO2 materials readily so as to improve the overall electrical conductivity between the electrodes during electrochemical processes. In electrochemical tests, the TiO2–rGO composites used as anodes in lithium-ion batteries exhibited superior performance with a reversible capacity of 100 mA h g−1 at 10 C for up to 100 cycles, as compared to 58 mA h g−1 at 10 C for up to 100 cycles from pure TiO2, suggesting great potential of this unique composite to function as high-rate lithium-ion battery materials.