Simple Electrostatic Self-assembly Method Research Articles

Ti3C2Tx MXene decorated with NiMnO3 / NiMn2O4 nanoparticles for simultaneous photocatalytic degradation of mixed cationic and anionic dyes

The present report investigated the different mass ratios of Ti3C2Tx MXene decorated NiMnO3 / NiMn2O4 nanoparticles and their enhancement of photocatalytic performance. The NiMnO3 / NiMn2O4 - Ti3C2Tx MXene nanocomposites were synthesized by a simple electrostatic self-assembly method. The physicochemical properties of nanocomposites were analyzed by XRD, SEM, and FESEM with EDAX, FTIR, PL, and UV-Visible spectrometer. The rhombohedral / cubic spinel structure of NiMnO3 / NiMn2O4 was confirmed by the XRD. The SEM and FESEM morphology show that spherical NiMnO3 / NiMn2O4 nanoparticles were decorated on the Ti3C2Tx MXene sheets and also present on the inside of the Ti3C2Tx MXene sheets. The average diameter of NiMnO3 / NiMn2O4 nanoparticles (46 nm) and the interlayer spacing of Ti3C2Tx MXene sheets (56 nm) were measured from FESEM analysis. The energy bandgap of NiMnO3 / NiMn2O4 - MXene nanocomposites was determined as ranging from 1.2 eV to 0.8 eV. The Ni, Mn, O, Ti, C, and F elemental compositions of the composites were analyzed by the EDAX. The effective photo-generated electron transferring from NiMnO3 / NiMn2O4 to Ti3C2Tx MXene was established by the PL quenching of NiMnO3 / NiMn2O4. The 100 % degradation efficiency was achieved in methylene blue (MB). The mixed dye degradation rates achieved for Rhodamine B (RhB), methyl orange (MO), and methylene blue (MB) for 90 %,72 %, and 100 % after 50 min in the presence of NiMnO3 / NiMn2O4 -Ti3C2Tx MXene (20 wt %). According to a scavenger experiment, the predominant species actively involved in the photodegradation process were revealed to •OH and •O2-.

Self-assembled cobalt disulfide-graphene oxide composite for efficient and environmentally friendly removal of antibiotic ornidazole through PMS activation

In this study, a highly active peroxymonosulfate (PMS) activator was prepared by the self-assembly of cobalt disulphide (CoS2) nanoparticles on the surface of graphene oxide nanosheets using a simple electrostatic self-assembly method. The catalysts were characterized, and their ability to activate PMS to eliminate ornidazole (ORZ) was assessed. Degradation experiments showed that the CoS2−GO/PMS system exhibited excellent ORZ degradation performance, removing 99.7 % of ORZ in 10 min. In four consecutive cycles, the reduction rate of ORZ removal by the composite catalyst decreased by only 1.8 %. Both radical quenching experiments and electron paramagnetic resonance (EPR) tests revealed that sulfate radical (SO4•-) and superoxide radical (O2•-) contributed to the major reactive oxygen species (ROS). X-ray photoelectron spectroscopy (XPS) results showed that the sulfur (S) species in CoS2 played an important role in the Co(III)/Co(II) cycle, driving the catalyst to exhibit excellent PMS activation. Liquid chromatography-mass spectrometry (LC-MS) was used to determine the possible decomposition processes and identify the intermediates of the ORZ medium. Remarkably, the biotoxicity assessment of degraded intermediates analyzed by ECOSAR software indicated the environmentally friendly features of the degradation process.

Visible light activation of ferrate(VI) by oxygen doped ZnIn2S4/black phosphorus nanolayered heterostructure: Accelerated oxidation of trimethoprim

The increasing consumption of antibiotics and their subsequent release to wastewater or groundwater and ultimately to the water supply (or drinking water) has great concerns. This paper presents a visible light (VL) activated ferrate(VI) (FeVIO42-, Fe(VI)) system to degrade the selected antibiotic, trimethoprim (TMP), efficiently. An oxygen doped ZnIn2S4 nanosheet (O-ZIS) coupled with a black phosphorus (BP) heterostructure (O-ZIS/BP), is fabricated by a simple electrostatic self-assembly method. The O-ZIS/BP photocatalyst is comprehensively characterized by surface and analytical techniques, which show superior separation efficiency of the photoinduced charge carriers in the heterostructure. A VL-O-ZIS/BP-Fe(VI) system achieves more than 80% removal in 1.0 min and complete removal of TMP in 3.0 min. Comparatively, only ⁓7% and ⁓24% of TMP are degraded by O-ZIS/BP and Fe(VI) in 1.0 min, respectively. The degradation experiments using probe molecules of reactive species and electron paramagnetic resonance (EPR) measurements reveal involvement of superoxide (O2-•), hydroxyl radical (•OH), and iron(V)/iron (IV) (FeV/FeIV) species in the mechanism of TMP degradation. Oxidized products of TMP are identified and reaction pathways are given. Theoretical calculations predict the initial attack on the TMP molecule by the reactive species in the VL-O-ZIS/BP-Fe(VI) system. The activation of Fe(VI) by VL-heterostructure photocatalysts accelerates the degradation of antibiotics, demonstrating its potential for water depollution.

Enhanced visible light catalytic activity of holey Ti3C2 based catalyst for azo dyes

The efficient degradation of organic dye pollutions is of great importance for environmental remediation. In this work, we prepared holey Ti3C2 (H-Ti3C2) and further synthesized H-Ti3C2/Ag/AgX (Cl, Br, I) Schottky catalysts by a simple electrostatic self-assembly method, and found that H-Ti3C2 could significantly improve the catalytic activity and stability of AgX. The H-Ti3C2/Ag/AgX composites showed great visible light absorption, obvious photocurrent intensity, and high charge transfer efficiency, ultimately improving photocatalytic efficacy for the degradation of methyl orange (MO) dye. The composite (5 wt%) H-Ti3C2/Ag/AgBr has the greatest photocatalytic activity, degrading 99.2% of the MO solution after 40 min of visible light irradiation, which is 1.08 and 2.02 times more than (5 wt%) Ti3C2 /Ag/AgBr and Ag/AgBr, respectively. The photocatalytic performance of H-Ti3C2/Ag/AgBr for MO dyes remains at 51% after five cycles. This result indicates that combining H-Ti3C2 with other photosensitive semiconductors to improve the catalytic activity and stability offers great possibilities. The present work not only provides a simplified method for the preparation of H-Ti3C2/Ag/AgX composites, but also offers a great possibility for H-Ti3C2 MXene as a co-catalyst to increase the photocatalytic degradation efficiency of organic pollutants.

Constructing metal-free heterophotocatalyst using two-dimensional carbon nitride sheets and violet phosphorene for highly efficient visible-light photocatalysis

Two-dimensional (2D) carbon nitride sheets (CNs) with nanoscale thickness have great potential in solar energy conversion owing to their intrinsic bandgap. However, their photocatalytic efficiency falls far below the practical requirements because the generated electron-hole pairs rapidly recombine. We construct a metal-free 2D p–n junction heterophotocatalyst from CNs and violet phosphorene (VP) using a simple electrostatic self-assembly method. The experimental results and density functional theory calculations show that the built-in electric field of the p–n junction promotes photogenerated carrier transport at the heterojunction interface, thereby promoting the separation of photogenerated electron-hole pairs. Under visible-light illumination, the visible-light photocatalytic hydrogen and CO production rates of the CNs/VP heterojunction were increased by 5.85 and 1.51 times, respectively, when compared to that of CNs. This study provides new insights into the design of metal-free heterogeneous photocatalysts with high catalytic activity.

Shuttle-inhibited 3D sandwich MXene/SnO2QDs sulfur host for high-performance lithium-sulfur batteries

Herein, sandwich-like Ti3C2Tx MXene/SnO2 quantum dots composites were synthesized as sulfur host, aiming to alleviate the shuttle effect of polysulfides present in lithium-sulfur batteries. SnO2 quantum dots (SnO2QDs) were introduced into the interlayer of MXene through a simple electrostatic self-assembly method, and the mass fraction of SnO2QDs was controlled to construct sandwich MXene/SnO2QDs. While SnO2QDs effectively alleviating the stacking tendency of MXene, Ti and Sn co-chemisorb polysulfides and the interlayer structure physically confines polysulfides. Significantly, the synergistic effect between MXene with SnO2QDs effectively alleviates the shuttle effect of polysulfides and buffers the volume expansion. Meanwhile, with the help of the catalysis of SnO2QDs, the liquid-solid reaction kinetics of lithium polysulfides converting to Li2S2/Li2S is accelerated. Electrochemical test results showed that the MXene/SnO2QDs/S cathode has a high initial discharge specific capacity (1147.6 mAh g−1 at 0.1 C, while MXene/S is only 615.4 mAh g−1), as well as excellent rate performance and cycling stability in Li-S batteries.

Constructing Z-scheme Fe3N/BiVO4 heterojunction via electrostatic self-assembly toward high visible-light photocatalytic hydrogen evolution

Fe3N/BiVO4 nanocomposites without noble metals were synthesized by a simple electrostatic self-assembly method. The morphology, crystal structure, composition and properties of the samples were studied by XRD, SEM, TEM, UV–vis and XPS. Under visible light irradiation, the average hydrogen production efficiency of 9 wt% Fe3N/BiVO4 nanocomposites reached 1420.7 μmol h−1 g−1, about 4 times than that of pure BiVO4. After four cycle experiments, the hydrogen production of 9 wt% Fe3N/BiVO4 is basically the same, indicating that the sample has good cycle stability. The enhancement of the activity and stability of the photocatalyst is mainly due to the fact that Fe3N is loaded on the surface of BiVO4, forming a Z-scheme heterojunction, which hinders the recombination of photogenerated electron hole pairs and greatly improves the separation efficiency of charge carriers.

Sea-urchin-like NiCo2S4 modified MXene hybrids with enhanced microwave absorption performance

The development of electromagnetic wave absorbing materials with lightweight and high absorption capacity is an effective way to solve electromagnetic wave pollution. Although the two-dimensional MXene material has become one of the most attractive electromagnetic wave absorbing materials due to its unique structure, the poor impedance matching makes it difficult to obtain both lightweight and efficient absorption capacity. Herein, few-layer MXene sheets and sea-urchin-like NiCo2S4 (NCS) hybrids were successfully synthesized by a simple electrostatic self-assembly method. MXene/NCS hybrids achieve good absorption performances. The maximum absorption bandwidth is 5.6 GHz at a matching thickness of only 1.53 mm with a filling ratio of only 10 wt%. In addition, the excellent microwave absorption performance is attributed to the improved impedance matching of MXene and the synergistic effects of dielectric loss and interfacial polarization. This work provides new ideas for the design and synthesis of materials with lightweight and efficient electromagnetic wave absorption.

Targeted co-delivery of a photosensitizer and an antisense oligonucleotide based on an activatable hyaluronic acid nanosystem with endogenous oxygen generation for enhanced photodynamic therapy of hypoxic tumors

Photodynamic therapy (PDT) is a promising cancer treatment modality with advantages of minimal invasiveness, repeatable therapy, and mild systemic toxicity. However, the limited bioavailability of photosensitizer (PS), tumor hypoxia, and the presence of antiapoptotic proteins in cancer cells, has hampered the efficiency of PDT. To address these limitations, herein, we developed a hyaluronic acid (HA) based nanosystem (HA-Ce6-Hemin@DNA-Protamine NPs, HCH@DP) loaded with chlorin e6 (Ce6, as PS), hemin (as mimetic catalase) and antisense oligonucleotide (ASO) of B-cell lymphoma 2 (Bcl-2) anti-apoptosis protein via a simple electrostatic self-assembly method for enhanced PDT of hypoxic solid tumors. The HCH@DP can target deliver the PS and ASO to tumor cells via cancer cell overexpressed HA receptors (i.e., CD44 or RHAMM). The Ce6 was released from HA-ss-Ce6 (HSC conjugates) after the reaction of cleavable disulfide bond with glutathione (GSH), which recovered the fluorescence and phototoxicity of Ce6 upon laser irradiation. Meanwhile, the catalase-mimicking hemin (degradation of HA-eda-hemin by hyaluronidase) decomposed the tumor overdressed endogenous H2O2 to oxygen, which relieved tumor hypoxia and further overcome hypoxia-associated resistance of PDT. Furthermore, the inhibition of Bcl-2 expression by Bcl-2 ASO also greatly improved the cellular sensitivity to PDT. Both in vitro and in vivo results showed the tumor cell targeting ability, hypoxia relief and significantly enhanced antitumor PDT efficacy of HCH@DP for hypoxic tumor cells upon laser irradiation. Thus, by improving the target delivery of PS and ASO, relieving tumor hypoxia, and down-regulation of anti-apoptotic proteins, this HCH@DP nanosystem achieved enhanced PDT efficiency against hypoxic tumors. In general, our work provided a promising strategy to increase the utilization of key components (PS and oxygen) of PDT and the cell sensitivity to PDT by targeting co-delivery PS and oligonucleotides to tumor cells via a biocompatible HA based carrier, thereby achieving efficiently PDT treatment of hypoxic solid tumors with potential translation possibility. Statement of significanceThe efficiency of PDT against solid tumor is severely restricted by the limited bioavailability of photosensitizer, tumor hypoxia, and the presence of antiapoptotic proteins in cancer cells. Herein, we have developed an activatable hyaluronic acid (HA) based nanosystem (HA-Ce6-Hemin@DNA-Protamine NPs, HCH@DP) via a simple electrostatic self-assembly method for PDT treatment of hypoxic solid tumors. The HCH@DP enabled to target co-delivery of photosensitizer and antisense oligonucleotide to tumor cells, overcoming tumor hypoxia through in situ oxygen production and improving cellular sensitivity by efficiently reducing anti-apoptosis effect of cancer cells for synergistically enhancing PDT efficiency. This work suggests a promising strategy to develop small molecule drug and oligonucleotides co-delivery nanoplatforms for efficiently PDT treatment of hypoxic solid tumor.

2D/2D Heterojunction of TiO2 Nanoparticles and Ultrathin G-C3N4 Nanosheets for Efficient Photocatalytic Hydrogen Evolution

Photocatalytic hydrogen evolution is considered one of the promising routes to solve the energy and environmental crises. However, developing efficient and low-cost photocatalysts remains an unsolved challenge. In this work, ultrathin 2D g-C3N4 nanosheets are coupled with flat TiO2 nanoparticles as face-to-face 2D/2D heterojunction photocatalysts through a simple electrostatic self-assembly method. Compared with g-C3N4 and pure TiO2 nanosheets, 2D/2D TiO2/g-C3N4 heterojunctions exhibit effective charge separation and transport properties that translate into outstanding photocatalytic performances. With the optimized heterostructure composition, stable hydrogen evolution activities are threefold and fourfold higher than those of pure TiO2, and g-C3N4 are consistently obtained. Benefiting from the favorable 2D/2D heterojunction structure, the TiO2/g-C3N4 photocatalyst yields H2 evolution rates up to 3875 μmol·g−1·h−1 with an AQE of 7.16% at 380 nm.

ZnO/COF S-scheme heterojunction for improved photocatalytic H2O2 production performance

Covalent organic frameworks (COFs) are burgeoning crystalline porous materials with great potential in photocatalysis, but their applications are mainly restricted by the speedy recombination rate of charge carriers. Herein, a step-scheme heterojunction ZnO/COF(TpPa-Cl) is fabricated by a simple electrostatic self-assembly method, and its photocatalytic H2O2 production performance is also investigated. The S-scheme heterojunction between ZnO and TpPa-Cl contributes to enhanced light absorption, promoted reactant adsorption capacity, increased redox power, and efficient separation and transfer of photogenerated charge carriers, leading to an improved photocatalytic H2O2 evolution activity. The optimal composite possesses the maximum H2O2 evolution rate of 2443 μmol·g−1·h−1 under simulated solar light irradiation, which is about 3.3 and 8.7 times higher than pristine ZnO nanoparticles and TpPa-Cl, respectively. Moreover, the charge transfer pathway in S-scheme heterojunction photocatalysts is well elucidated. This investigation provides designing guidelines in the construction of other COF-based S-scheme heterojunctions.

Visible-light-responsive NaBiO3/UiO-67 heterojunction with enhanced photocatalytic performance

Photocatalysts for the degradation of pollutants, including semiconductors and metal-organic frameworks (MOFs), are currently limited by poor visible-light response, high carrier recombination rate, and finite quantum efficiency. In this study, we fabricated a new heterojunction using NaBiO3 and the MOF, UiO-67, by a simple electrostatic self-assembly method to achieve enhanced photocatalytic performance. Under visible-light irradiation, the NaBiO3/UiO-67 heterojunction exhibited better photocatalytic activity for tetracycline degradation than neat UiO-67 and NaBiO3. Its high degradation efficiency (88.6%) can be attributed to the efficient separation of photoinduced carriers, as evidenced by the results from photocurrent result, electrochemical impedance spectroscopy, and surface photovoltage spectroscopy analyses. Electron spin resonance spectroscopy indicated that h+, ·O2–, and ·OH played dominant roles in the photocatalytic degradation of tetracycline. Liquid chromatography confirmed that, rather than being adsorbed, tetracycline was successfully photodegraded. Finally, an electron transfer mechanism for the generation of intermediates during tetracycline degradation was also proposed based on liquid chromatography-mass spectrometry and keto-enol tautomerism. These findings demonstrate the promising application of semiconductor/MOF heterojunctions as photocatalysts for pollutant degradation.

Constructing van der Waals Heterogeneous Photocatalysts Based on Atomically Thin Carbon Nitride Sheets and Graphdiyne for Highly Efficient Photocatalytic Conversion of CO2 into CO.

Atomically thin two-dimensional (2D) carbon nitride sheets (CNs) are attracting attention in the field of photocatalytic CO2 reduction. Because of the rapid recombination of photogenerated electron-hole pairs and limited more active sites, the photocatalytic efficiency of CNs cannot meet the actual requirements. Here, atomically thin 2D/2D van der Waals heterostructures of metal-free graphdiyne (GDY)/CNs are fabricated through a simple electrostatic self-assembly method. Experimental characterizations along with first-principles calculations show that the introduction of GDY in CNs promoted the transport of photogenerated carriers in the melon chain, thus suppressing the recombination of photogenerated electron-hole pairs. Both in situ FTIR measurements and DFT calculation confirm that the introduced GDY served as the CO2 adsorption site and enhanced the CO2 adsorption capacity of the CNs/GDY heterostructure. Thanks to the 2D/2D van der Waals heterojunction, the optimized CNs/GDY enhances significantly the CO generation rate up to 95.8 μmol g-1 that is 19.2-fold higher than that of CNs. This work provides a viable approach for the design of metal-free van der Waals heterostructure-based photocatalysts with high catalytic activity.

Indoor light boosted formaldehyde abatement over electrostatic self-assembled graphitic carbon nitride/ceric oxide at ambient temperature

The pursuit of efficient noble metal-free catalysts is highly desirable for possible practical application of ambient-temperature removal of indoor formaldehyde (HCHO). In this work, graphitic carbon nitride/ceric oxide (g-C3N4/CeO2) heterojunctions were prepared via a simple electrostatic self-assembly method, which possessed moderate catalytic performances for HCHO elimination in the dark at ambient temperature. Indoor fluorescent-light irradiation obviously sped up the conversion of HCHO into CO2 and H2O over g-C3N4/CeO2 heterojunctions. Particularly, C3N4/CeO2 with theoretical 20 wt% of g-C3N4 (20%g-C3N4/CeO2) exhibited a HCHO removal efficiency of ca. 73% and HCHO conversion ratio of ca. 70% under fluorescent-lamp illumination, higher than the corresponding ones of 47% and 26% in the dark, respectively. The fluorescent-lamp irradiation promoting HCHO degradation over C3N4/CeO2 was proposed on the basis of the visible-light response of individual g-C3N4 and CeO2, and the distinct heterostructure conducive to the separation of photo-generated carriers as well as intrinsic capability of CeO2 favoring the formation of extra active oxygen species. This work might provide a vane of energy saving and emission reduction by taking full advantage of indoor lights for environmental remediation.

Enhanced photocatalytic hydrogen evolution over semi-crystalline tungsten phosphide

Increasing the separation efficiency and transfer rate of photogenerated charges is the dominant factor for improving photocatalytic activity. Herein, we successfully prepared semi-crystalline WP (SC-WP) with good optical properties and as a cocatalyst to modify CdS nanorods (CdS NRs) to construct SC-WP/CdS (PD) composite catalyst by simple electrostatic self-assembly method for photocatalytic hydrogen evolution. Two high-efficiency and stable photocatalytic hydrogen evolution systems were constructed with 1.0 M ammonium sulfite solution and 10 vol% lactic acid solution as sacrificial agents, respectively. Surprisingly, the maximum photocatalytic H2 production rate of 15446.21 μmol h−1 g−1 is obtained over 10PD composite, which is 10.58 times greater than that of pure CdS. The improved photocatalytic activity can be attributed to the fact that the SC-WP nanoparticles provides a large number of exposed active sites on the surface of CdS for hydrogen evolution reaction, which can efficiently capture photogenerated electrons from CdS nanorods and promotes the transport and separation of light-induced charges. And the introduction of SC-WP nanoparticles with excellent optical properties can efficiently improve the visible light absorption range and the utilization rate of the absorbed light of the PD composite. In addition, the SC-WP nanoparticles show semi-crystalline state, which is also conducive to enhancing the photocatalytic activity.

Pursuit of a high-capacity and long-life Mg-storage cathode by tailoring sandwich-structured MXene@carbon nanosphere composites

Sandwich-structured MXene@C nanospheres with an enlarged interlayer spacing were pioneeringly prepared by a simple electrostatic self-assembly method, and exhibited excellent electrochemical performance as a cathode for rechargeable Mg batteries.

Effect of Elevated Temperature Annealing on Nafion/SiO₂ Composite Membranes for the All-Vanadium Redox Flow Battery.

Conducting Nafion/SiO2 composite membranes were successfully prepared using a simple electrostatic self-assembly method, followed by annealing at elevated temperatures of 240, 270, and 300 °C. Membrane performance was then investigated in vanadium redox flow batteries (VRB). These annealed composite membranes demonstrated lower vanadium permeability and a better selectivity coefficient than pure Nafion membranes. The annealing temperature of 270 °C created the highest proton conductivity in the Nafion/SiO2 composite membranes. The microstructures of these membranes were analyzed using transmission electron microscopy, small-angle X-ray scattering, and positron annihilation lifetime spectroscopy. This study revealed that exposure to high temperatures resulted in an increase in the free volumes of the composite membranes, resulting in improved mechanical and chemical behavior, with the single cell system containing composite membranes performing better than systems containing pure Nafion membranes.

Enhanced Fenton, photo-Fenton and peroxidase-like activity and stability over Fe3O4/g-C3N4 nanocomposites

We prepared the Fe3O4/g-C3N4 nanoparticles (NPs) through a simple electrostatic self-assembly method with a 3:97 weight ratio to investigate their Fenton, photo-Fenton and oxidative functionalities besides photocatalytic functionality. We observed an improvement of the Fenton and photo-Fenton activities of the Fe3O4/g-C3N4 nanocomposites. This improvement was attributed to efficient charge transfer between Fe3O4 and g-C3N4 at the heterojunctions, inhibition of electron-hole recombination, a high surface area, and stabilization of Fe3O4 against leaching by the hydrophobic g-C3N4. The obtained NPs showed a higher degradation potential for rhodamine B (RhB) dye than those of Fe3O4 and g-C3N4. As compared to photocatalysis, the efficiency of RhB degradation in the Fenton and photo-Fenton reactions was increased by 20% and 90%, respectively. Additionally, the horseradish peroxidase (HRP) activity of the prepared nanomaterials was studied with 3,3,5,5-tetramethylbenzidinedihydrochloride (TMB) as a substrate. Dopamine oxidation was also examined. Results indicate that Fe3O4/g–C3N4 nanocomposites offers more efficient degradation of RhB dye in a photo-Fenton system compared with regular photocatalytic degradation, which requires a long time. Our study also confirmed that Fe3O4/g-C3N4 nanocomposites can be used as a potential material for mimicking HRP owing to its high affinity for TMB. These findings suggest good potential for applications in biosensing and as a catalyst in oxidation reactions.

Fabrication of gold nanoparticles/graphene oxide films with surface-enhanced Raman scattering activity by a simple electrostatic self-assembly method

The paper reports a simple electrostatic self-assembly method to fabricate the gold nanoparticles/graphene oxide (Au NPs@GO) films which present superior SERS activity. The Au NPs@GO films with different layers construction and surface compositions (with Au NPs or GO as the outer layer) are obtained simply by changing the self-assembly cycles. Results indicate that the film with two assembly cycles (F-2 film) exhibits the best SERS activity towards R6G molecules compared with that of one assembly cycle (F-1 film) and three assembly cycles (F-3 film) due to the high loadings of the absorbed Au NPs exposed on the surface of the film. Meanwhile, the Raman enhancement effect of the F-2 film with the outer layer of Au NPs is better than that of the outer layer covering with GO sheets (F-2-GO) possibly owing to the optimal synergetic effect of Au NPs and GO. Furthermore, our fabricated Au NPs@GO films present favorable reproducibility and high stability, which are significant for the practical application of these SERS substrates.

Constructing one-dimensional silver nanowire-doped reduced graphene oxide integrated with CdS nanowire network hybrid structures toward artificial photosynthesis.

A ternary hybrid structure of one-dimensional (1D) silver nanowire-doped reduced graphene oxide (RGO) integrated with a CdS nanowire (NW) network has been fabricated via a simple electrostatic self-assembly method followed by a hydrothermal reduction process. The electrical conductivity of RGO can be significantly enhanced by opening up new conduction channels by bridging the high resistance grain-boundaries (HGBs) with 1D Ag nanowires, which results in a prolonged lifetime of photo-generated charge carriers excited from the CdS NW network, thus making Ag NW-RGO an efficient co-catalyst with the CdS NW network toward artificial photosynthesis.