The elimination of dyes from textile wastewater with a lower carbon footprint is highly contingent on the design of green catalysts. Here, we innovatively developed ultralong one-dimensional BiTiO/TiO heterojunction nanofibers electrospinning so as to photocatalytically degrade dyes efficiently and sustainably through the utilisation of renewable solar irradiation. The heterostructured BiTiO/TiO nanofibers exhibited desirable activity in the visible light region through the slight shift of the absorption edge to a longer wavelength.
View Article and Find Full Text PDFWe unprecedentedly report spatially separated CoN nanodots on carbon nanotubes (CNTs) a facile formamide condensation reaction. To our knowledge, CoN-CNTs outperform the activities of current catalysts in peroxymonosulfate activation. CoN-CNT-oriented radical-free degradation of contaminants shows robust anti-interference capacity toward environmental conditions.
View Article and Find Full Text PDFTo address the worldwide oil and water separation issue, a novel approach was inspired by natural phenomena to synthesize superhydrophilic and underwater superoleophobic organic/inorganic nanofibrous membranes via a scale up fabrication approach. The synthesized membranes possess a delicate organic core of PVDF-HFP and an inorganic shell of a CuO nanosheet structure, which endows super-flexible properties owing to the merits of PVDF-HFP backbones, and superhydrophilic functions contributed by the extremely rough surface of a CuO nanosheet anchored on flexible PVDF-HFP. Such an organic core and inorganic shell architecture not only functionalizes membrane performance in terms of antifouling, high flux, and low energy consumption, but also extends the lifespan by enhancing its mechanical strength and alkaline resistance to broaden its applicability.
View Article and Find Full Text PDFCarbapenem-resistant Enterobacteriaceae (CREs)-mediated infections remain a huge public health concern. CREs produce enzymes such as metallo-β-lactamases (MBLs), which inactivate β-lactam antibiotics. Hence, developing efficient molecules capable of inhibiting these enzymes remains a way forward to overcoming this phenomenon.
View Article and Find Full Text PDFWastewaters with high concentrations of organic pollutants pose a great challenge for membrane filtration due to their severe fouling propensity. In this study, a hydrogel forward osmosis (FO) membrane is explored for treating wastewaters of high concentration organic pollutants. This FO membrane has an ultrathin hydrogel selective layer, which is highly hydrophilic (water contact angle as low as 18°) and smooth (surface roughness <5 nm).
View Article and Find Full Text PDFSurfactant stabilized oil-in-water nanoemulsions pose a severe threat to both the environment and human health. Recent development of membrane filtration technology has enabled efficient oil removal from oil/water nanoemulsion, however, the concurrent removal of surfactant and oil remains unsolved because the existing filtration membranes still suffer from low surfactant removal rate and serious surfactant-induced fouling issue. In this study, to realize the concurrent removal of surfactant and oil from nanoemulsion, a novel hierarchically-structured membrane is designed with a nanostructured selective layer on top of a microstructured support layer.
View Article and Find Full Text PDFGlobally, efficient oil-water separation for surfactant-stabilized oil-water emulsions has been in urgent demand. The current options available for separation are neither sustainable nor resistant to fouling. Herein, we introduce a hierarchically nanostructured TiO2/Fe2O3 composite membrane, which is capable of separating surfactant-stabilized oil-water emulsions with high separation efficiency.
View Article and Find Full Text PDFAn oil spill needs timely cleanup before it spreads and poses serious environmental threat to the polluted area. This always requires the cleanup techniques to be efficient and cost-effective. In this work, a lightweight and compressible sponge made of carbon-silica nanofibers is derived from electrospinning nanotechnology that is low-cost, versatile, and readily scalable.
View Article and Find Full Text PDFA green approach was successfully developed to reap three environmental benefits simultaneously: (1) clean water production, (2) hydrogen (H2) generation, and (3) well-dispersed in situ Cu(2+) recovery for direct TiO2-CuO composite reclamation, by exploiting the synergistic integration of photocatalytic reaction of Cu-EDTA and one-dimensional (1D) ultralong and ultrathin TiO2 nanofibers. In this light-initiated system, Cu-EDTA was oxidized by TiO2 thus releasing Cu(2+) which was reduced and recovered through uniform adsorption onto the long and porous TiO2 surface. A win-win platform was thus attained, on which Cu was recovered while providing active sites for H2 generation via photoreduction of H2O and enhancing photo-oxidation of remaining intermediate oxidation byproducts.
View Article and Find Full Text PDFThe nanostructures of TiO2 significantly affect its photocatalytic activity. In this work, various TiO2 nanostructures have been successfully synthesized, including one-dimensional (1D) TiO2 nanotube, 1D TiO2 nanowire, three-dimensional (3D) TiO2 sphere assembled by nanoparticles (TiO2 sphere-P) and 3D TiO2 sphere assembled by nanosheets (TiO2 sphere-S). The results of photodegradation activity towards acid orange 7 (AO7) indicate that the photodegradation efficiency of TiO2 sphere-S is the highest among the investigated TiO2 nanostructures, even though the specific surface area of TiO2 sphere-S is lower than that of TiO2 nanotube.
View Article and Find Full Text PDFA novel free-standing and flexible electrospun carbon-silica composite nanofibrous membrane is newly introduced. The characterization results suggest that the electrospun composite nanofibers are constructed by carbon chains interpenetrated through a linear network of 3-dimensional SiO2. Thermogravimetric analysis indicates that the presence of insulating silica further improve the thermal resistance of the membrane.
View Article and Find Full Text PDFPhotocatalytic degradation of pollutants under visible light provides a new door to solve the water contamination problem by utilizing free and renewable sunlight. The search for highly efficient photocatalysts with hierarchical nanostructures remains crucial for accessing this new door. In this work, a new hierarchical nanostructured photocatalyst is designed and synthesized, for the first time, by anchoring In2S3 flower-like nanostructures on non-woven carbon nanofiber (CNF).
View Article and Find Full Text PDFThis manuscript describes the characterization of as-synthesized titanate nanotube (TNT) and its sorption behaviours on cadmium with the interactions of inorganic anions. The X-ray diffraction and transmission electron microscopy found that the nanotube is in sodium titanate crystal phase (Na2Ti3O7) and the pores of TNT are bimodally distributed with nominal pore sizes of 3 and 15 nm. In the binary systems between TNT and anions, the binding affinity is fluoride > phosphate > sulphate with sulphate being the least preferred.
View Article and Find Full Text PDFDisposal of mercury waste has always provided unique challenges due to its high degree of complexity and volatility. This study evaluated the feasibility of using waste LF slag to form a cementitious matrix capable of providing an effective stabilization/solidification solution for the treatment of mercury wastes. The new matrix was synthesized and simulated through a combination of alkali activation and autoclaving process and doped with mercury nitrate at increasing dosage while monitoring the final form of the mercury and its effects on the mineral stability and structure of the new matrix.
View Article and Find Full Text PDFMembrane technology provides a new choice to solve the looming clean water scarcity crisis. However, severe membrane fouling is a great challenge in the membrane-based water treatment field. In this study, a new hierarchical TiO /V O multifunctional membrane was fabricated for the first time by assembling TiO /V O composites as a functional layer on top of the polymer supporting layer.
View Article and Find Full Text PDFCu species was introduced into TiO2 nanotube prepared by hydrothermal method via a facile adsorption-dry process. The fabricated sample exhibited excellent H2 generation activity (76.3 mmol h(-1) g(-1)(catalyst)), which was higher than most of the reported Cu incorporated TiO2 samples, even superior to some Pt/Pd/Au/Ni incorporated TiO2.
View Article and Find Full Text PDFSynthesis of efficient visible-light-driven photocatalyst is urgent but challenging for environmental remediation. In this work, for the first time, the hierarchical plasmonic sulfonated graphene oxide-ZnO-Ag (SGO-ZnO-Ag) composites were prepared through nanocrystal-seed-directed hydrothermal method combining with polyol-reduction process. The results indicated that SGO-ZnO-Ag exhibited much faster rate in photodegradation of Rhodamine B (RhB) and disinfection of Escherichia coli (E.
View Article and Find Full Text PDFMultifunctional nanocomposites (GO-TiO2-Ag) integrating 2D GO sheets, 1D TiO2 nanorods and 0D Ag nanoparticles were synthesized via a facile two-phase method and characterized by various analytical techniques including TEM, EDS and XRD. The GO-TiO2-Ag nanocomposites demonstrate remarkably enhanced photocatalytic activities in degrading AO 7 and phenol under solar irradiation compared with GO-TiO2 and GO-Ag. They also exhibit excellent intrinsic antibacterial activity toward Escherichia coli, as well as significantly enhanced photo-biocidal capability over GO-TiO2 and GO-Ag.
View Article and Find Full Text PDFHierarchical graphene oxide (GO)-TiO2 composite microspheres with different GO/TiO2 mass ratios were successfully prepared by mixing GO and TiO2 microspheres under ultrasonic conditions. Ultrasonication helped the GO and TiO2 microsphere to uniformly mix on the microscale. The results showed that the GO-TiO2 composites that were prepared by ultrasonic mixing exhibited significantly higher hydrogen-evolution rates than those that were synthesized by simple mechanical grinding, owing to synergetic effects, including enhanced light absorption and scattering, as well as improved interfacial charge transfer because of the excellent contact between the GO sheets and TiO2 microspheres.
View Article and Find Full Text PDFGraphene oxide (GO) was reduced by stirring the solution contaning GO sheets with platinum (Pt) nanoparticles and formic acid at room temperature for 72 h. The resulting reduced graphene oxide-Pt (RGO-Pt) nanocomposites were characterized, and it was found that the Pt nanoparticles of size 4-6 nm were anchored onto the RGO sheets. The reduction of GO was facilitated by formic acid catalysed by the Pt nanoparticles.
View Article and Find Full Text PDFIt was found that with replenishment, powdered activated carbon (PAC) in the membrane bioreactor (MBR) would develop biologically activated carbon (BAC) which could enhance filtration performance of a conventional MBR. This paper addresses two issues (i) effect of PAC size on MBR (BAC) performance; and (ii) effect of sludge retention time (SRT) on the MBR performance with and without PAC. To interpret the trends, particle/floc size, concentration of mixed liquor suspended solid (MLSS), total organic carbon (TOC), short-term filtration properties and transmembrane pressure (TMP) versus time are measured.
View Article and Find Full Text PDFHierarchical 3D dendritic TiO2 nanospheres building with ultralong 1D TiO2 nanoribbon/wires were hydrothermally synthesized via controlling the hydrolysis rate of precursor by EG. It is found that the EG and Cl(-) in the precursor solution are the dominant factors in controlling the hydrolysis rate of Ti(4+) from TTIP, and the growing direction of 1D TiO2, respectively. Through optimizing the molar ratio of TTIP:EG, hierarchical 3D dendritic TiO2 nanospheres building with long 1D nanoribbons (TiO2 nanoribbon spheres) were synthesized at a molar ratio of TTIP:EG = 1:2.
View Article and Find Full Text PDFIt is still a challenge to photocatalytically cogenerate clean water and energy from dye wastewater owing to the relatively low photocatalytic efficiency of photocatalysts. In this study, novel-structured TiO2/CuO composite nanofibers were successfully fabricated via facile electrospinning. For the first time, the TiO2/CuO composite nanofibers demonstrated multifunctional ability for concurrent photocatalytic organic degradation and H2 generation from dye wastewater.
View Article and Find Full Text PDFGraphene oxide (GO)-CdS composites were synthesized via a novel two-phase mixing method successfully. CdS nanoparticles were uniformly self-assembled on GO sheets at water/toluene interface. The photocatalytic degradation (photodegradation) and disinfection activities of GO-CdS composites were investigated thoroughly.
View Article and Find Full Text PDFWe report a facile non-hydrothermal method for the large-scale production of hierarchical TiO(2) nanorod spheres for the photocatalytic elimination of contaminants and killing bacteria. Crescent Ti/RF spheres were prepared by deliberately adding titanium trichloride (TiCl(3)) to the reaction of resorcinol (R) and formaldehyde (F) in an open reactor under heating and stirring. The hierarchical TiO(2) nanorod spheres were obtained by calcining the crescent Ti/RF spheres in a furnace in air to burn off the RF spheres.
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