Showing papers by "Hong Liu published in 2015"
TL;DR: Graphene-based nitrogen self-doped hierarchical porous carbon aerogels were synthesized for supercapacitor electrode application by using chitosan as a raw material through a carefully controlled aerogel formation and activation process as discussed by the authors.
503 citations
TL;DR: Narrow-bandgap semiconductor WS2 nanosheets are active photocatalysts, either under visible or under NIR irradiation, via photogeneration of an electron-hole pair, with a low rate of recombination.
Abstract: Narrow-bandgap semiconductor WS2 nanosheets are active photocatalysts, either under visible or under NIR irradiation. The photocatalyst functions are confirmed via photogeneration of an electron-hole pair, with a low rate of recombination.
465 citations
TL;DR: A large-area, flexible sensor matrix can map 2D pressure distributions in situ, either statically or dynamically, and the piezophotonic effect is proposed to initiate the mechanoluminescence process once a dynamic mechanical strain is applied.
Abstract: X. Wang, H. Zhang, Prof. L. Dong, Dr. D. Peng, Dr. A. Zhang, Prof. Y. Zhang, Prof. H. Liu, Prof. C. Pan, Prof. Z. L. Wang Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of Sciences Beijing 100083 , PR China E-mail: donglin@binn.cas.cn; cfpan@binn.cas.cn; zhong.wang@mse.gatech.edu H. Zhang, Prof. L. Dong School of Materials Science & Engineering Zhengzhou University Zhengzhou 450001 , PR China R. Yu, Prof. Z. L. Wang School of Materials Science and Engineering Georgia Institute of Technology Atlanta , GA 30332–0245 , USA
430 citations
TL;DR: In this article, the authors report the UV-visible-NIR broad spectrum active photocatalytic property of CQDs/hydrogenated TiO2 (H-TiO2) nanobelt heterostructures.
396 citations
TL;DR: The piezoelectric effect combined with photoelectric conversion realizes an ultrasonic-wave-driven piezophotototronic process in the hybrid photocatalyst, which is the fundamental of sonophotocatalysis.
Abstract: An electric field built inside a crystal was proposed to enhance photoinduced carrier separation for improving photocatalytic property of semiconductor photocatalysts. However, a static built-in electric field can easily be saturated by the free carriers due to electrostatic screening, and the enhancement of photocatalysis, thus, is halted. To overcome this problem, here, we propose sonophotocatalysis based on a new hybrid photocatalyst, which combines ferroelectric nanocrystals (BaTiO3) and semiconductor nanoparticles (Ag2O) to form an Ag2O–BaTiO3 hybrid photocatalyst. Under periodic ultrasonic excitation, a spontaneous polarization potential of BaTiO3 nanocrystals in responding to ultrasonic wave can act as alternating built-in electric field to separate photoinduced carriers incessantly, which can significantly enhance the photocatalytic activity and cyclic performance of the Ag2O–BaTiO3 hybrid structure. The piezoelectric effect combined with photoelectric conversion realizes an ultrasonic-wave-driven...
383 citations
TL;DR: In this article, a 3D porous Bi2MoO6 nanosheet/TiO2 nanobelt heterostructures with a few-layer and uniform Bi 2MoO 6 nanosheets was developed by a simple hydrothermal method.
Abstract: We employed TiO2 nanobelts as the synthetic template and developed three-dimensional (3D) porous Bi2MoO6 nanosheet/TiO2 nanobelt heterostructures with a few-layer and uniform Bi2MoO6 nanosheets by a simple hydrothermal method. The as-prepared Bi2MoO6 nanosheet/TiO2 nanobelt heterostructure shows an excellent photodegradation performance under UV and visible light irradiation. Importantly, such a heterostructure possesses high photocatalytic oxygen production with a rate of 0.668 mmol h–1 g–1. Moreover, the Bi2MoO6 nanosheet/TiO2 nanobelt heterostructure shows an enhanced photoelectochemistry performance under irradiation of solar illumination. The current research can offer an alternative route for designing a 3D heterostructure system to effectively utilize broad-spectrum solar light.
321 citations
TL;DR: The structure of the human P2Y1 receptor with a nucleotide antagonist MRS2500 at 2.7 A resolution and with a non-nucleotide antagonist BPTU with 2.2 A resolution was reported in this article.
Abstract: In response to adenosine 5'-diphosphate, the P2Y1 receptor (P2Y1R) facilitates platelet aggregation, and thus serves as an important antithrombotic drug target. Here we report the crystal structures of the human P2Y1R in complex with a nucleotide antagonist MRS2500 at 2.7 A resolution, and with a non-nucleotide antagonist BPTU at 2.2 A resolution. The structures reveal two distinct ligand-binding sites, providing atomic details of P2Y1R's unique ligand-binding modes. MRS2500 recognizes a binding site within the seven transmembrane bundle of P2Y1R, which is different in shape and location from the nucleotide binding site in the previously determined structure of P2Y12R, representative of another P2YR subfamily. BPTU binds to an allosteric pocket on the external receptor interface with the lipid bilayer, making it the first structurally characterized selective G-protein-coupled receptor (GPCR) ligand located entirely outside of the helical bundle. These high-resolution insights into P2Y1R should enable discovery of new orthosteric and allosteric antithrombotic drugs with reduced adverse effects.
296 citations
TL;DR: A review of synthetic methods, properties, surface modification, and applications of TiO2 nanobelts is presented here and an outline of important directions of future research into the synthesis, modification,and applications of this unique material is given.
Abstract: TiO2 semiconductor nanobelts have unique structural and functional properties, which lead to great potential in many fields, including photovoltaics, photocatalysis, energy storage, gas sensors, biosensors, and even biomaterials. A review of synthetic methods, properties, surface modification, and applications of TiO2 nanobelts is presented here. The structural features and basic properties of TiO2 nanobelts are systematically discussed, with the many applications of TiO2 nanobelts in the fields of photocatalysis, solar cells, gas sensors, biosensors, and lithium-ion batteries then introduced. Research efforts that aim to overcome the intrinsic drawbacks of TiO2 nanobelts are also highlighted. These efforts are focused on the rational design and modification of TiO2 nanobelts by doping with heteroatoms and/or forming surface heterostructures, to improve their desirable properties. Subsequently, the various types of surface heterostructures obtained by coupling TiO2 nanobelts with metal and metal oxide nanoparticles, chalcogenides, and conducting polymers are described. Further, the charge separation and electron transfer at the interfaces of these heterostructures are also discussed. These properties are related to improved sensitivity and selectivity for specific gases and biomolecules, as well as enhanced UV and visible light photocatalytic properties. The progress in developments of near-infrared-active photocatalysts based on TiO2 nanobelts is also highlighted. Finally, an outline of important directions of future research into the synthesis, modification, and applications of this unique material is given.
275 citations
TL;DR: In this article, ultrathin MoO 3 nanocrystals were assembled on 3D graphene oxide frameworks via a hydrothermal reaction forming a layered structure by oxygen-bonding interactions at the interface.
187 citations
TL;DR: Small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS are reported to provide a selective approach to disrupt cellular copper transport and establish copper chaperones as new targets for future developments in anticancer therapies.
Abstract: Copper is a transition metal that plays critical roles in many life processes. Controlling the cellular concentration and trafficking of copper offers a route to disrupt these processes. Here we report small molecules that inhibit the human copper-trafficking proteins Atox1 and CCS, and so provide a selective approach to disrupt cellular copper transport. The knockdown of Atox1 and CCS or their inhibition leads to a significantly reduced proliferation of cancer cells, but not of normal cells, as well as to attenuated tumour growth in mouse models. We show that blocking copper trafficking induces cellular oxidative stress and reduces levels of cellular ATP. The reduced level of ATP results in activation of the AMP-activated protein kinase that leads to reduced lipogenesis. Both effects contribute to the inhibition of cancer cell proliferation. Our results establish copper chaperones as new targets for future developments in anticancer therapies.
168 citations
TL;DR: In this paper, sulfur and nitrogen self-doped carbon nanosheets are prepared as efficient non-metal catalysts for hydrogen evolution reaction (HER) by thermal decomposition of peanut root nodules, an abundant biowaste.
TL;DR: It is supposed that the plasmon-mediated charge distribution within the alloy NPs is mainly responsible for the enhanced photocatalytic activity of the bimetallic nanostructures.
Abstract: Plasmonic photocatalysts composed of Au and bimetallic Au–Pd alloy nanoparticles (NPs) on one-dimensional TiO2 nanobelts (TiO2-NBs) were used for the aerobic oxidation of benzyl alcohol under visible light irradiation. Remarkable light-promoted activity was observed for the as-synthesized M/TiO2-NB (M = Au, Au–Pd) nanostructures based on the TiO2(B)/anatase heterostructured nanobelt. The difference in band structure and the well matched interface between the TiO2(B) and anatase phases, coupled with the one-dimensional nanostructure, enable an enhanced charge transfer within the heterostructured nanobelt. This inter-phase charge transfer greatly facilitates the flow of hot electrons from the metal NPs to TiO2 and promotes benzyl alcohol oxidation. This efficient electron transfer was identified by the much higher photocurrent response measured for the Au/TiO2-NB nanostructure with the TiO2(B)/anatase heterojunction than those with either of the single phases under visible light irradiation. Alloying Au with Pd in Au–Pd/TiO2-NB results in a significant improvement in the visible light-promoted activity compared to the monometallic Au/TiO2-NB sample. It is supposed that the plasmon-mediated charge distribution within the alloy NPs is mainly responsible for the enhanced photocatalytic activity of the bimetallic nanostructures.
TL;DR: In this paper, the authors summarized recent progress in the enhancement of photocatalytic activities under various light irradiations and discussed the challenges and perspectives of the photocatalysis under different lights irradiations.
Abstract: Owing to extensive industrial revolutions, the harvesting of sunlight for environmental remediation has attracted extensive attention and a number of potential photocatalysts have been reported. These photocatalysts were prepared according to their effectiveness under various light irradiations, that is, from UV/Vis to near-infrared (NIR) regions and finally to full solar light spectrum. This review briefly summarizes recent progress in the enhancement of photocatalytic activities of prepared photocatalysts under various light irradiations. To understand the photocatalytic process, photocatalytic mechanisms and band-structure engineering are discussed in detail in this review. Moreover, various effective photocatalysts are taken as examples of the photocatalytic process under various light irradiations. Finally, the challenges and perspectives of photocatalysis under different lights irradiations are presented.
TL;DR: In this article, tetragonal In2S3 nanoparticles were synthesized to display broad spectrum photocatalytic properties under ultraviolet (UV), visible, and near-infrared irradiation from a simple hydrothermal method.
Abstract: We, herein, report the synthesis of the first photocatalyst, tetragonal In2S3 nanoparticles, to display broad-spectrum photocatalytic properties under ultraviolet (UV), visible, and near-infrared irradiation from a simple hydrothermal method. The as-synthesized In2S3 nanoparticles have irregular morphology and possess a primary particle size of 5–20 nm with high photo-degradation abilities under UV (96.2% within 30 min), visible light (95.4% within 3 h) and near-infrared light (67.2% within 3 h), a phenomenon extremely rare in character with respect to a broad class of photocatalysts that have a single crystalline phase. This current work in broadband spectrum photocatalysis affords a new paradigm for the full utilization of solar light.
TL;DR: ZnIn2S4-g-C3N4 composites with different g-C 3N4 contents were synthesized by a facile hydrothermal method and characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), XPS, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), high-resolution transmission electron microcopy (HRTEM), N2 adsorption-desorption (DRS), photoluminescence (PL) spectrosc
Abstract: ZnIn2S4–g-C3N4 sheet-on-sheet nanocomposites with different g-C3N4 contents were synthesized by a facile hydrothermal method and characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), high-resolution transmission electron microcopy (HRTEM), N2 adsorption–desorption, ultraviolet-visible diffuse reflection spectroscopy (DRS), photoluminescence (PL) spectroscopy and photoelectrochemical (PEC) experiments. The photocatalytic activities of these samples were evaluated by the photocatalytic H2-production and degradation of organic pollutants (methyl orange and phenol) under visible-light illumination (λ > 420 nm). The results showed that the ZnIn2S4–g-C3N4 composite photocatalysts displayed higher photocatalytic activity than the pristine g-C3N4 and ZnIn2S4 both for H2-evolution and degradation of pollutants. The optimal g-C3N4 content was determined to be 40 wt%, and the corresponding H2-production rate was 953.5 μmol h−1 g−1, which was about 1.91 times higher than that of pure ZnIn2S4. The enhanced photocatalytic activity of ZnIn2S4–g-C3N4 composites should be attributed to the well-matched band structure and intimate contact interfaces between ZnIn2S4 and g-C3N4, which led to the effective transfer and separation of the photogenerated charge carriers. Moreover, the ZnIn2S4–g-C3N4 composites showed excellent stability during the photocatalytic reactions under visible light. A possible mechanism of the enhanced photocatalytic activity of ZnIn2S4–g-C3N4 composites was proposed and supported by the PL and PEC results.
TL;DR: In this paper, a double-shelled NiO/rGO/TiO 2 heterostructured coaxial nanocables with zero-bandgap graphene at the interface between p-type NiO and n-type TiO 2 can further enhance the separation of photogenerated carriers.
TL;DR: In this article, a sound driven triboelectric nanogenerator (TENG) was fabricated based on electrospun polyvinylidene fluoride (PVDF) nanofibers.
TL;DR: This study provides a facile and low-cost method for the large scale production of Sn3O4 based materials in various applications and shows the highest photocatalytic activity of the scaly hybrid nanobelts.
Abstract: A novel scaly Sn3O4/TiO2 nanobelt heterostructured photocatalyst was fabricated via a facile hydrothermal route. The scaly Sn3O4 nanoflakes can be synthesized in situ and assembled on surface coarsened TiO2 nanobelts through a hydrothermal process. The morphology and distribution of Sn3O4 nanoflakes can be well-controlled by simply tuning the Sn/Ti molar ratio of the reactants. Compared with single phase nanostructures of Sn3O4 and TiO2, the scaly hybrid nanobelts exhibited markedly enhanced photoelectrochemical (PEC) response, which caused higher photocatalytic hydrogen evolution even without the assistance of Pt as a co-catalyst, and enhanced the degradation ability of organic pollutants under both UV and visible light irradiation. In addition to the increased exposure of active facets and broad light absorption, the outstanding performance is ascribed to the matching energy band structure between Sn3O4 and TiO2 at the two sides of the heterostructure, which efficiently reduces the recombination of photo-excited electron–hole pairs and prolongs the lifetime of charge carriers. Both photocatalytic assessment and PEC tests revealed that Sn3O4/TiO2 heterostructures with a molar ratio of Sn/Ti of 2/1 exhibited the highest photocatalytic activity. This study provides a facile and low-cost method for the large scale production of Sn3O4 based materials in various applications.
TL;DR: The results demonstrated the feasibility of using GQDs as traceable drug delivery systems with the ability for the pH-triggered delivery of drugs into target cells.
Abstract: Graphene quantum dots (GQDs) were rationally fabricated as a traceable drug delivery system for the targeted, pH-sensitive delivery of a chemotherapeutic drug into cancer cells. The GQDs served as fluorescent carriers for a well-known anticancer drug, doxorubicin (Dox). The whole system has the capacity for simultaneous tracking of the carrier and of drug release. Dox release is triggered upon acidification of the intracellular vesicles, where the carriers are located after their uptake by cancer cells. Further functionalization of the loaded carriers with targeting moieties such as arginine-glycine-aspartic acid (RGD) peptides enhanced their uptake by cancer cells. DU-145 and PC-3 human prostate cancer cell lines were used to evaluate the anticancer ability of Dox-loaded RGD-modified GQDs (Dox-RGD-GQDs). The results demonstrated the feasibility of using GQDs as traceable drug delivery systems with the ability for the pH-triggered delivery of drugs into target cells.
TL;DR: In this article, a fully functional photoelectrocatalysis device was constructed by connecting single crystalline TiO2 nanowires assembled on graphite microfibers to a wind-driven triboelectric nanogenerator (WDTENG).
TL;DR: In this article, the authors used metal organic frameworks formed by Cu and trimesic acid to construct porous composites with adjustable composition and various morphologies, including cube, octahedron, rod and wire.
Abstract: CuO/Cu2O porous composites with adjustable composition and various morphologies, including cube, octahedron, rod and wire, have been successfully achieved. These structures are inherited from metal organic frameworks formed by Cu and trimesic acid and can be regulated under mild conditions. While tested in CO oxidation, these porous composites exhibited a high performance.
TL;DR: This study synthesized a porous MnCo2O4.5 nanoneedle/carbon aerogel hybrid nanostructure that exhibits a high energy density and capacitance retention and is applicable to carbon-based supercapacitor applications.
Abstract: Current applications of carbon-based supercapacitors are limited by their low energy density One promising strategy to enhance the energy density is to couple metal oxides with carbon materials In this study, a porous MnCo2O45 nanoneedle/carbon aerogel hybrid nanostructure was synthesized by assembling MnCo2O45 nanoneedle arrays on the surface of channel walls of hierarchical porous carbon aerogels derived from chitosan for the supercapacitor application The synthetic process of the hybrid nanostructure involves two steps, ie the growth of Mn-Co precursors on carbon aerogel by a hydrothermal process and the conversion of the precursor into MnCo2O45 nanoneedles by calcination The carbon aerogel exhibits a high electrical conductivity, high specific surface area and porous structure, ensuring high electrochemical performance of the hybrid nanostructure when coupled with the porous MnCo2O45 nanoneedles The symmetric supercapacitor using the MnCo2O45 nanoneedle/carbon aerogel hybrid nanostructure as the active electrode material exhibits a high energy density of about 843 Wh kg(-1) at a power density of 600 W kg(-1) The voltage window is as high as 15 V in neutral aqueous electrolytes Due to the unique nanostructure of the electrodes, the capacitance retention reaches 86% over 5000 cycles
TL;DR: The findings suggest that megalin/cubilin and lysosome rupture are involved in albumin-triggered tubular injury and TI, and implicates the active control of albuminuria as a critical strategy to halt the progression of CKD.
TL;DR: In this paper, a meso-microporous carbon was prepared by the combination of a template method and chemical activation with earth abundant cellulose and lignosulphonate as the sources.
Abstract: The notion of environmental protection and renewable sources for energy conversion and storage has become particularly important nowadays. In this research, a meso-microporous carbon was prepared by the combination of a template method and chemical activation with earth abundant cellulose and lignosulphonate as the sources. The as-synthesized meso-microporous carbon contained mesopores generated by regeneration of cellulose with the assistance of a silica template, and micropores created by chemical activation of carbon. Such a unique porous structure makes the as-synthesized meso-microporous carbon the ideal electrode active material for energy storage. The two-electrode symmetric supercapacitors built using the meso-microporous carbon electrodes show a specific capacitance of 286 F g−1 at a current density of 0.25 A g−1 in aqueous electrolyte. More importantly, the symmetric supercapacitor achieves a high energy density of 13 W h kg−1 while at a high power density of 27 kW kg−1. It is demonstrated that using renewable natural sources for the manufacturing of porous carbon with high performance for energy storage can be an effective way to lower the cost of a supercapacitor.
TL;DR: The facile synthesis of hydrogenated TiO2 (H-TiO2) nanobelts are reported, which exhibit excellent UV and visible photocatalytic decomposing of methyl orange (MO) and water splitting for hydrogen production.
TL;DR: Oxygen reduction catalysts based on heteroatom-doped mesoporous carbon nanotubes loaded with Co2P nanoparticles were skilfully fabricated and could strongly promote the ORR catalytic performance of the heteroatomatic carbon structures.
TL;DR: Polarized ferroelectric crystal lithium niobate wafers with different cuts are selected and results illustrate that the positively charged wafer surface enhances rBMMSCs osteogenic differentiation.
Abstract: Polarized ferroelectric crystal lithium niobate wafers with different cuts are selected to offer differently charged surfaces By induction of the mesenchymal stem cells differentiation into osteoblasts on different charged surfaces, the specific osteogenic-associated markers are assessed and the results illustrate that the positively charged wafer surface enhances rBMMSCs osteogenic differentiation
TL;DR: The observations demonstrate the potential of low-cost SnO2-based sensors with controlled morphology and reactive facets for detecting gases around room temperature.
Abstract: A SnO2 gas sensor was prepared by a two-step oxidation process whereby a Sn(II) precursor was partially oxidized by a hydrothermal process and the resulting Sn3O4 nanoplates were thermally oxidized to yield SnO2 nanoplates. The SnO2 sensor was selective and responsive toward ethanol at a temperature as low as 43 °C. This low sensing temperature stems from the rapid charge transport within SnO2 and from the presence of high-energy (001) facets available for oxygen chemisorption. SnO2/TiO2 nanobelt heterostructures were fabricated by a similar two-step process in which TiO2 nanobelts acted as support for the epitaxial growth of intermediate Sn3O4. At temperatures ranging from 43 to 276 °C, the response of these branched nanobelts is more than double the response of SnO2 for ethanol detection. Our observations demonstrate the potential of low-cost SnO2-based sensors with controlled morphology and reactive facets for detecting gases around room temperature.
TL;DR: A strategy to achieve well-dispersed and size-controlled supported metal oxides through the manageable growth of a metal organic framework (Cu-BTC) on TiO2 followed by pyrolysis is described.
Abstract: Supported metal oxide nanoparticles are important in heterogeneous catalysis; however, the ability to tailor their size, structure, and dispersion remains a challenge. A strategy to achieve well-dispersed and size-controlled supported metal oxides through the manageable growth of a metal organic framework (Cu-BTC) on TiO2 followed by pyrolysis is described.
TL;DR: In this article, a hybrid nanostructured photocatalyst by assembling Sn3O4 nanosheets on N-doped TiO2 nanotubes has been constructed with enhanced broad spectrum photocatalytic properties, which can harness UV and visible light to decompose organic contaminants in aqueous solutions and split water to hydrogen.
Abstract: Semiconductor nanostructures with photocatalytic activity have many potential applications including remediation of environmental pollutants and photocatalytic hydrogen evolution. An effective way of promoting photocatalytic activity is by creating heterogeneous photocatalysts. In this paper, a hybrid nanostructured photocatalyst with desired three-dimensional (3D) nanoarchitecture by assembling Sn3O4 nanosheets on N-doped TiO2 nanotubes has been constructed with enhanced broad spectrum photocatalytic properties, which can harness UV and visible light to decompose organic contaminants in aqueous solutions and split water to hydrogen. Photocatalytic tests showed that the Sn3O4/N-TiO2 hierarchical hybrid nanostructures possessed a much higher degradation rate of methyl orange and hydrogen evolution rate than that of the unmodified TiO2 nanotubes, N-TiO2 nanotubes, Sn3O4 nanosheets and Sn3O4/TiO2 hybrid nanostructures. The mechanism related to the enhancement of the photocatalytic activity was discussed. Deposition of Sn3O4 nanosheets onto N-TiO2 nanotubes resulted in a dramatic increase in light-induced generation of hydroxyl radicals, superoxides and singlet oxygen, and the production of holes and electrons. This work is the first instance of combining Sn3O4 with N-TiO2, the Sn3O4/N-TiO2 hierarchical hybrid nanostructures show good photocatalytic performance. This study is potentially applicable to a range of 3D hybrid nanostructures with promising applications in photocatalysis and relevant areas.