Gisselrivers7873

The PVO exhibits the capacitance retentions of 82% after 2000 cycles and 56% after 10,000 cycles, whereas this value is only 29% after 3000 cycles in NH4Cl electrolyte. The findings reveal that this strategy can effectively reduce the diffusion resistance of ammonium ions and improve the energy storage efficiency of PVO. The flexible QSS PVO//active carbon hybrid supercapacitor (FQSS PVO//AC HSC) device is assembled and exhibits outstanding capacitance, long cycle stability, good mechanical stability and potential practical applications. This work may open up a new window for the study on the improved electrochemical properties of electrode materials for NH4+ storage.Constructing noble metal-doped g-C3N4/carbon composites is a feasible route to overcome the intrinsic drawbacks of pristine g-C3N4 for enhanced activity of CO2 photoreduction. MEK activation Herein, a novel Ag-doped g-C3N4/biomass-derived carbon composite with hollow bird's nest-like (Ag-g-C3N4/BN-C) is designed and prepared via a simple yet effective one-step pyrolysis method. In the Ag-g-C3N4/BN-C, the highly-dispersed Ag nanoparticles (20-30 nm) with the surface plasmon resonance (SPR) effect act as a significant cocatalyst not only to efficiently trap the photogenerated electrons from g-C3N4 to boost the separation of photogenerated electron-hole pairs but also to produce additional active "hot electrons", while the conductive quasi-spherical hollow structure of BN-C doubles the specific surface area with multiple reflections of light, providing abundant active sites and more utilization efficiency of light energy. As a result, the Ag-g-C3N4/BN-C exhibits a remarkably enhanced CO evolution rate of 33.3 μmol·g-1·h-1 without addition of any sacrificial reagents and photosensitizers, superior to those of both the pristine g-C3N4 and many reported g-C3N4-based counterparts. The findings of this work demonstrate a good indication for integrating g-C3N4 with SPR-dependence noble metal and renewable biomass-derived carbon for enhanced CO2 photoreduction, which may be extended to modify other semiconductor materials for more photocatalytic applications with enhanced activity.The ecosystems and human health were seriously threatened by hexavalent chromium (Cr(VI)) in wastewater. In this article, using the idea of the highly matched energy band structure between indium sulfide (In2S3) and MIL-53(Fe), a Type-II heterojunction has been constructed by loading In2S3 on MIL-53(Fe) microrod to overcome the fault like high recombination rates of photogenerated electron-holes of In2S3. The composite with 201 mass ratio of In2S3 to MIL-53(Fe) (IM-2) was adopted as an optimal sample for efficient photocatalytic Cr(VI) reduction under visible light. Various characterization techniques were used to verify the characteristics of composites and delved into the structure-effect relationship between this heterojunction and its activity. Results showed that the reaction rate constants of the photoreduction process over IM-2 was ~ 4 and 26 times higher than those of pure In2S3 and MIL-53(Fe), respectively, and the catalyst could maintain superior removal efficiency (88.6%) and steady crystal structure after four cycles. First-principles calculations further illustrated that the heterostructure formed between In2S3 and MIL-53(Fe) could effectively accelerate the separation of photogenerated electrons and holes, thus improving the photocatalytic reduction performance. Moreover, the active species analyses revealed that the superoxide radicals and electrons were mainly involved in the reduction of Cr(VI).2D/2D heterojunction photocatalysts with excellent photocatalytic activity highlight considerable potential in water disinfection. Here, an oxidized Sb/g-C3N4 2D/2D nanosheets heterojunction (Sb-SbOx/CNS) was constructed based on a facile one-step liquid-phase exfoliation method using concentrated sulfuric acid. By doing so, bulk Sb and g-C3N4 were exfoliated simultaneously and then, intercalated each other. Compared with CNS and Sb-SbOx, the obtained Sb-SbOx/CNS demonstrated better photocatalytic disinfection activity towards Escherichia coli K-12 (E. coli K-12) under visible light irradiation. The 5% oxidized Sb/g-C3N4 2D/2D nanosheets heterojunction (5.0% Sb-SbOx/CNS) exhibited the best photocatalytic performance and admirable cycling stability, which was ascribed to the unique structure where the interfacial charge separation was strengthened by the strong coupling effect between Sb-SbOx and CNS. Meanwhile, the fundamental mechanism of photocatalytic disinfection was also proposed. The photogenerated ROS (reactive oxygen species) violently attacked the E. coli K-12 membrane, creating massive and irreparable holes on the cell membrane. The leakage of cations (K+, Na+, Ca2+ and Mg2+), adenosine triphosphate, total soluble sugar and protein accelerated the destruction of E. coli K-12. Trapping experiments suggested that the photocatalytic disinfection process against E. coli K-12 was dominated by h+ generated on 5.0% Sb-SbOx/CNS. This work offers a new promising way to modify the 2D/2D heterojunction featuring efficient photocatalytic disinfection performance.The dynamic behavior of electron-hole pairs at the interface of the nanocomposites is important for photoelectrochemical catalysis, but it is difficult to characterize. Here we construct a ternary titanium dioxide/nitrogen-doped carbon dot/gold (TiO2/NCD/Au) complex as the model catalyst to investigate the kinetic indexes at their interfaces. Under irradiation (200 mW cm-2), the photocurrent density of TiO2/NCD/Au is 10.26 mA cm-2, which is higher than those of TiO2/Au (4.34 mA cm-2), TiO2/NCD (7.55 mA cm-2) and TiO2 (3.34 mA cm-2). The evolved oxygen of TiO2/NCD/Au reaches 125.8 μmol after 5000 s test. The energy bands of complexes are very similar to that of the unmodified TiO2 catalyst due to the low content modification of NCDs and Au. In addition, the transient photovoltage (TPV) tests with a series of control samples show differences about the carriers' separation and transfer process, which verify that Au can increase the separation quantity of electron-hole pairs while NCDs play a more important role on the increase of the separation quantity and separation rate simultaneously. This work quantifies the function of each component in a composite catalyst and deepens the understanding of the catalyst interface design.Constructing a p-n heterojunction is a feasible strategy to manipulate the dynamic behaviors of photogenerated carriers through an internal electric field. Herein, a novel highly efficient indium oxide/bismuth oxyiodide (In2O3/BiOI) p-n junction photocatalyst was fabricated using a facile ionic liquid-assisted precipitation method for the first time. The morphologies were modified by adding different amounts of acetic acid solution. Their hierarchical architecture was beneficial for adsorbing contaminants in wastewater, while the in-situ formed p-n heterojunction between BiOI and In2O3 facilitated interfacial charge transfer and improved the quantum efficiency. Their visible light-responsive photocatalytic activities were systematically investigated by photocatalytic o-phenylphenol (OPP) and 4-tert-butylphenol (PTBP) oxidation. The degradation rate of OPP over In2O3/BiOI-2 was up to 5.67 times higher than that for BiOI. The excellent activity of In2O3/BiOI should be attributed to the rapid interfacial charge transfer, depressed carrier recombination, and proper band potentials. Trapping experiments and electron paramagnetic resonance characterizations confirmed the generation of hydroxyl radicals (•OH) and superoxide radicals (•O2-), which have played a key role in decomposing pollutants. The intermediate products generated during the photocatalytic degradation of OPP were detected and identified by liquid chromatography-mass spectrometry. Meanwhile, their possible molecular structures and degradation pathways have also been inferred.In this study, an iron(III)-loaded magnetic chitosan/graphene oxide composite (Fe-MCG) was synthesized and applied for the adsorptive removal of sulfosalicylic acid (SSA) in aqueous solution. The results obtained from the application of various characterization techniques such as scanning electron microscopy (SEM), vibrating-sample magnetometry (VSM), and X-ray photoelectron spectroscopy (XPS) prove the successful formation of the composite with enhanced microstructure and superparamagnetic properties. The adsorption capacity of Fe-MCG towards SSA via batch mode reaches up to 135 mg/g at 293 K. The adsorption of SSA onto Fe-MCG is driven by monolayer adsorption with the chemical and physical adsorption processes both playing active roles. The Langmuir isotherm and pseudo-second-order kinetic models were observed to best describe the equilibrium adsorption and kinetic processes, respectively. The values obtained for the associated thermodynamic parameters confirm that the adsorptive process is spontaneous, exothermic and entropy-increasing. The efficacy and reusability of the spent Fe-MCG was studied using 0.01 mol/L NaOH solution. The kinetic process for the desorption of SSA from Fe-MCG is well described by the pseudo-second-order kinetic model. Based on the experimental results and XPS analysis, the underlying mechanisms for the uptake of SSA onto Fe-MCG involve electrostatic forces, complexation, π-π stacking, and hydrogen bonding. Overall, the excellent features of Fe-MCG enhance its potential as an adsorbent for the sequestration of SSA in environmental media.Cuprous oxide (Cu2O) is a p-type semiconductor with excellent catalytic activity and stability that has gained much attention because it is non-toxic, abundant, and inexpensive. Porous carbon materials have large specific surface areas, which offer abundant electroactive sites, enhance the electrical conductivity of materials, and prevent the aggregation of Cu2O nanocubes. In this study, a composite with high electrocatalytic activity was prepared based on Cu2O nanocubes anchored onto three-dimensional macroporous carbon (MPC) by a simple, eco-friendly, and cheap method for hydrazine detection. Due to the synergistic effect of MPC and Cu2O, the sensor exhibited high electrocatalytic activity, sensitivity, better selectivity, and low limit of detection. The resulting sensor could be a sensitive and effective platform for detecting hydrazine and promising practical applications.Lipase is the most widely used enzyme in industry. Due to its unique "lid" structure, lipase can only show high activity at the oil-water interface, which means that water is needed in the catalytic esterification process. However, the traditional lipase catalytic system cannot effectively control "micro-water" in the esterification environment, resulting in the high content of free water, which hinders the esterification reaction and reduces the yield. In this paper, a promising strategy of esterification catalyzed by polyacrylamide hydrogel immobilized lipase is reported. The porous polyacrylamide hydrogel microspheres (PHM) prepared by inverse emulsion polymerization are used as carrier to adsorb lipase by hydrogen bonding interaction. These hydrogel microspheres provide a "micro-water environment" for lipase in the anhydrous reaction system, and further provide an oil-water interface for "interface activation" of lipase. The obtained lipase-porous polyacrylamide hydrogel microspheres (L-PHMs) exhibit higher temperature and pH stability compared with free lipase, and the optimum enzymatic activity reach 1350 U/g (pH 6, 40 °C).