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Recently, the successful synthesis of biphenylene network (BPN) monolayers (A. V. Matetskiy et al., Appl. Surf. Sci., 2021, 539, 148144) has resulted in significant progress in the study of carbon materials. Inspired by this material, the electronic structures and transport properties of graphene–BPN–graphene (G–BPN–G) nanojunction-based nanodevices are systematically studied using density functional theory and non-equilibrium Green's function methods. The results show that the I–V curves of two-dimensional (2D) and quasi-one-dimensional (Q1D) G–BPN–G devices exhibit intrinsic negative differential resistance (NDR) characteristics regardless of the electronic transport direction. But the electronic transport following the zigzag direction (Iz) is faster than that along the armchair direction (Ia) below a bias of 0.8 V, but when the bias is further increased, Ia is greater than Iz. For armchair-edged G–BPN–G nanoribbons, the metal or semi-conductive behaviors are dependent on their width and the kinds of passivated atoms on the edges. Specifically, the nanoribbons achieve the transition from semiconducting to metallic with an increase of the number of BPN in the heterogeneous structure by F-passivation and H-passivation. Moreover, O-passivated G–BPN–G nanoribbons always show metallic characteristics. Adjustable metal to semiconductor devices can be achieved by varying the combination of H- and O-passivated cells in Q1D G–BPN–G nanoribbon-based nanodevices. Overall, these interesting results demonstrate that these novel G–BPN–G devices have promising practical applications in future electronic nanodevices. [ABSTRACT FROM AUTHOR]

Construction of a heterojunction between quantum dots and TiO2 nanowire arrays via electrostatic self-assembly is rarely reported. In this work, mercury lamp irradiation was used to change the surface potential of WO3 quantum dots and TiO2 nanowire arrays, resulting in WO3 quantum dots tightly attached on the surface of TiO2 nanowire through electrostatic self-assembly. Photoelectrochemical measurements showed that the WO3 quantum dots formed a type II heterojunction with the TiO2 nanowire arrays rather than serving as carrier-trapping sites. In the self-assembly system, the TiO2 nanowire arrays provide a charge-transfer channel for the WO3 quantum dots, greatly improving the contribution of the WO3 quantum dots to the photocurrent. Quantitative calculations showed that the improvement of the bulk carrier-separation efficiency was the reason for the enhanced photoelectrochemical performance of the self-assembled system. The photocurrent density of the optical self-assembled system at 1.23 V (vs. RHE) was ∼5.5 times as high as that of the TiO2 nanowire arrays. More importantly, the self-assembled system exhibited excellent photoelectrochemical stability. [ABSTRACT FROM AUTHOR]

Rapid and quantitative detection of nitrobenzene (NB) in wastewater is of great significance to protect the natural environment and human health. In this work, bifunctional Ln@Zr-MOFs based on UiO-66 were successfully fabricated by partially replacing terephthalic acid (H2BDC) ligands with m-phthalic acid (m-H2BDC) ligands and post-synthetic modification (PSM) with Ln3+ (Ln3+ = Eu3+, Tb3+). The "antenna effect" of the m-H2BDC ligands makes Ln@Zr-MOFs exhibit the characteristic emissions of Ln3+. By adjusting the amount and type of Ln3+, controllable color-tuning emissions can be easily realized, which endows them with a great application prospect for white LEDs. On the other hand, Eu10@Zr-MOFs can serve as a turn-off fluorescent switch of NB because the red emission from Eu3+ can be easily quenched by NB through a photoinduced electron transfer (PET) process between NB and its ligands, and as a result, NB is successfully recognized. Particularly, Eu10@Zr-MOFs as a fluorescent probe have shown many appealing properties, such as high sensitivity (limit of detection is 1.04 μM, limit of quantification is 3.48 μM, and Ksv = 24459.71 M−1), quick response (less than 60 s), a broad response window (0–180 μM), excellent selectivity, and strong anti-interference ability. The real detection results of NB concentration in natural water samples have demonstrated that the reported Eu10@Zr-MOFs are a potential fluorescent material that can precisely and sensitively perform fluorescence sensing of NB. [ABSTRACT FROM AUTHOR]

Uncontrollable Li dendrite growth increases the risks of cell short-circuit or even safety accidents, severely hindering the practical application of lithium metal anodes (LMAs). Herein, N/S-co-doped mesoporous carbon (NSMC) nanospheres with ordered mesoporous channels prepared by an in situ polymerization and facile pyrolysis approach are designed and can effectively regulate the Li nucleation/deposition behavior. As a host, NSMC has high affinity towards Li ions owing to the electronegative surface, which provides a low Li nucleation barrier and promotes the subsequent dendrite-free deposition. Moreover, a robust solid electrolyte interphase (SEI) layer is established, synergistically improving the cycling stability, even under high areal capacity. With these advantages, ultra-stable Li@NSMC‖Li@NSMC symmetric cells were achieved with a lifetime of up to 2700 h and 400 h at a high areal capacity of 4 and 20 mA h cm−2, respectively. Full cells with commercial LiFePO4 cathodes deliver a high reversible capacity of 121 mA h g−1 after 300 cycles at 2C with a retention ratio of 84%, showing great potential in practical applications. [ABSTRACT FROM AUTHOR]

Flexible supercapacitors have attracted increasing interest due to their high power density, long-term cycling life and excellent safety. Like other energy storage devices, flexible supercapacitors exhibit serious performance degradation as they work in extremely cold and/or sweltering climates, which greatly limit their practical applications. Here, we demonstrate a polymer hydrogel with high ionic conductivity for flexible supercapacitors with high performance and excellent climate tolerance. The wide temperature adaptability of the polymer hydrogel is enabled by introducing an additive of dimethyl sulfoxide, which can form abundant hydrogen bonds with water molecules and functional groups of polymer molecules. The optimized hydrogel exhibits high ionic conductivities of 0.82 and 1.12 S m−1 at −20 and 100 °C, respectively, comparable with that at room temperature. Using the polymer hydrogel as an electrolyte, the resulting supercapacitors not only show high electrochemical performance, but also exhibit high capacitance retention up to 91% and 85% at both low (−20 °C) and high (100 °C) temperatures, compared with that at room temperature. In addition, the developed supercapacitors possess excellent mechanical flexibility even at −20 °C. Polymer hydrogels with wide temperature tolerance could be easily functionalized and broadly used for other flexible energy devices and electronics working in harsh environments in the future. [ABSTRACT FROM AUTHOR]

Recently, a novel sp2 hybridized planar two-dimensional carbon allotrope consisting of tetra, penta and octagonal (TPO) rings has attracted much interest. Its quasi-one-dimensional counterpart, the penta-tetra-pentagonal (PTP) molecule chain, can be obtained by carving it from the 2D TPO-carbon structure, and it has also had much attention. Here, we present a first-principles study for the spin-dependent electron transport for model devices which consist of PTP molecule chains with different lengths sandwiching between two semi-infinite zigzag-edged graphene nanoribbon (zGNR) electrodes. By using the non-equilibrium Green's function formalism in combination with density-functional theory, a length-independent, stable and perfect spin-filtering can be found in these PTP molecules based devices with parallel configuration in electrodes. Further, the coexistence of dual spin-filtering and -rectifying with a high ratio is demonstrated in the device with antiparallel spin configuration in electrodes. Interestingly, a two-state molecular conformational switch can be realized by mechanically rotating the plane between the PTP molecule chain and zGNR electrodes from coplanar to perpendicular, and the device exhibits a substantially large current modulation, and the ON/OFF switching ratio can reach up to 103 within the considered bias window. Furthermore, the physical mechanisms are revealed and discussed by presenting the transmission spectra at the Fermi energy in combination with the separation of local device density of states at the Fermi level. All these theoretical predictions might trigger a new avenue to expand the application of carbon allotrope materials in nanoelectronics. [ABSTRACT FROM AUTHOR]

A carbon phosphide (CP) monolayer, a 2D structure derived from the same 3-fold coordination found both in graphene and phosphorene, has been successfully synthesized in an experiment recently. In this paper, we investigated the modulation of electronic structures and transport characteristics of 2D nanosheets and quasi-1D nanoribbons of CP nanomaterials in the α-phase by using first-principles density functional theory simulation. The calculated band structures show that the band gap of 2D CP nanosheets progressively increases as the uniform biaxial strain changes from compression to stretching. However, the biaxial strain cannot change the indirect band gap behavior of the original 2D CP nanosheet. In addition, the band structures of quasi-1D nanoribbons with different styles of H-passivated zigzag edges have also been studied. The results show that the H-passivated zigzag PC ribbons with two P edges are semiconductors with indirect band gaps, and the gaps decrease with increasing width of ribbons. However, the H-passivated CP nanoribbons with one P-atom terminated edge in combination with one P-atom edge, and H-passivated CC nanoribbons with two C-atom terminated edges display metallic behaviors. The semi-conductive or metallic behaviors of zigzag CP nanoribbons can be explained by presenting the wave function of their energy band around the Fermi level. Finally, the electronic transport properties of different CP nanoribbon based nanojunctions are studied in which arise the interesting negative differential resistance or rectification effects in their current–voltage characteristic curves. [ABSTRACT FROM AUTHOR]

Here, we present the microemulsion method using sodium dodecylbenzenesulfonate and hydrofluoric acid for the in situ synthesis of brightly luminescent CsPbBr3/CsPb2Br5 composite nanocrystals (NCs) in aqueous solution. The obtained CsPbBr3/CsPb2Br5 composite NCs exhibit a photoluminescence quantum yield of 77.0% and a full width at half maximum of 16.0 nm. And solid-state back-lighting devices were fabricated by combining CsPbBr3/CsPb2Br5 composite NCs and red-emitting K2SiF6:Mn4+ phosphors with blue light. The as-fabricated device exhibits a wide color gamut of about 95.8% of the Rec. 2020. This work provides a green, low-cost, and in situ water-phase route to synthesize high-quality cesium lead halide NCs for their practical applications in solid-state back-lighting devices. [ABSTRACT FROM AUTHOR]

Fluorescent gold nanoclusters (AuNCs) are emerging as novel imaging contrast agents. These molecules offer excellent prospects for non-invasive tumor diagnosis strategies because of their ultra-small size, tunable emissions from the visible to the near-infrared range, excellent biocompatibility, and suitable pharmacokinetic properties. In this tutorial review, we introduce the physiological features of the tumor microenvironment, followed by a description of AuNC pharmacokinetics. Next, we outline the strategies used to deliver AuNCs specifically to tumor tissues for in vivo tumor imaging. Finally, examples are presented to highlight the application potential of AuNCs for in vivo tumor imaging. [ABSTRACT FROM AUTHOR]

Graphene and carbon nanotubes (CNTs) have been widely used as electrode materials for electrochemical energy storage devices (e.g., supercapacitors), but often result in limited performance because of their serious aggregation. To address the aforementioned crucial issue, herein, a three-dimensional seamless graphene/carbon nanotubes (G/CNTs) hybrid was fabricated by directly growing aligned CNTs arrays from the surface of graphene in foam, during which a simpler solution approach with low energy consumption was used to coat the catalyst for growth of CNTs, replacing conventional electron-beam vapor deposition. By using the seamless G/CNTs hybrids as electrodes, two-electrode solid-state multifunctional supercapacitors have been developed. Due to the excellent photo-conductive effect of graphene and CNTs, the capacitance of the obtained supercapacitor increased by 1.9 times under one solar light illumination (1.0 kW m−2), compared with that of the device in the dark. The specific capacitance of supercapacitors could be further improved by incorporating a conducting polymer of polyaniline in G/CNTs hybrids. Furthermore, the newly developed supercapacitors can well maintain their original capacitance as they were bent to any angle and stretched to a strain of 240%, indicating excellent flexibility and stretchability. The unique three-dimensional seamless G/CNTs hybrids are also promising to be used for building other multifunctional electronic devices beyond energy storage. [ABSTRACT FROM AUTHOR]

Thermally robust and optically transparent phosphor ceramics are now attracting great attention as promising luminescent materials for high-power white light-emitting diodes (WLEDs). Here, we report a new CaF2-YAG:Ce phosphor ceramic in which the yellow-emitting YAG:Ce particles are embedded in a non-luminescent CaF2 ceramic matrix. The composite phosphor ceramic was fabricated at a very low sintering temperature of 700 °C by using a simple hot-pressing method. No detectable interfacial reaction occurs between the YAG:Ce particle and the CaF2 matrix. Owing to the excellent optical properties and high thermal conductivity of CaF2, the prepared CaF2-YAG:Ce phosphor ceramic shows a high quantum efficiency (IQE = 83.2%), and a low thermal quenching (only 9% loss in luminescence at 150 °C). WLEDs, fabricated by combining the CaF2-YAG:Ce phosphor ceramic with a 460 nm blue chip of 2 W, exhibited bright white light with a luminous flux of 359.7 lm, a color temperature of 4021–7941 K and a color rendering index of 70.1–82.7. The composite phosphor ceramic showed a better performance than the traditional single-phase YAG:Ce ceramic, enabling it to be used in high-power WLEDs. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs), as a new kind of fluorescent pH nanoprobe, have attracted significant attention due to their favorable optical properties and excellent environmental friendliness. However, a real ratiometric and self-calibrating fluorescent pH nanoprobe based on intrinsic dual-emission CDs (DECDs) still remains scarce. In this study, we reported a kind of intrinsic DECDs for ratiometric fluorescence pH sensing. Interestingly, the two emission bands at 393 and 580 nm from the DECDs simultaneously display strong pH-dependence but with an adverse variation trend. The ratio of the intensity of 393 and 580 nm matches well with an empirical function against pH in the range from 2.2 to 8.0, and further, an excellent linear relationship is presented in an acidic environment with a responsive pH range of 2.2–4.0. Moreover, the rapid response time (＜1 min), high sensitivity, good reversibility and pinpoint accuracy (±1.0%) for pH sensing reveals that the as-prepared DECDs can act as excellent ratiometric luminescent nanoprobes for pH detection. We hope that this study will offer new possibilities for expanding the applications of luminescent CDs in chemical sensing, biomedicine and food safety. [ABSTRACT FROM AUTHOR]

Herein, we report a new highly luminescent material, a CsPbBr3@NH4Br (CPBr–NB) nanocomposite, formed via an ion-exchange reaction, which can reach up to a few micrometers in size. The CPBr–NB solid-state luminophores with a unique core@shell structure effectively avoid photoluminescence quenching and maintain excellent optical properties of the perovskite nanocrystals. Most importantly, the nanocomposite exhibits excellent water resistance and thermal stability. Such superior optical merits endow them with promising potential in lighting and displays. [ABSTRACT FROM AUTHOR]

Two-dimensional layered nanomaterials, such as graphene and metal sulfides, exhibit great potential to be used as efficient electrode materials for high-performance energy storage devices. However, it remains a great challenge to achieve highly stretchable devices based on the above mentioned nanomaterials because their layered structures are easily damaged even under very little tensile strength. In this paper, compact graphene and its composite films were fabricated by a facile pressing method and showed high flexibility and stretchability (100%). By using the compact graphene/MoS2 composites as electrodes, flexible all-solid-state supercapacitors with a volumetric capacitance of 19.44 F cm−3 (70.00 mF cm−2) were developed. These newly-developed graphene-based supercapacitors can bear a high tensile strain of 60% with slight performance degradation and can retain 87% of their original capacitance after 300 stretching cycles to 30% strain, exhibiting much higher stretchability and stability than most of the graphene-based stretchable supercapacitors reported previously. These compact graphene-based materials may prove to be a promising candidate to be used as electrodes for other stretchable electronics. [ABSTRACT FROM AUTHOR]

Protein-stabilized gold nanoclusters (protein-Au NCs) have been an attractive frontier of nanoparticle research. Due to their unique fluorescence properties, high stability, environmentally friendly synthetic routes and nontoxicity, protein-Au NCs could find applications in highly sensitive and selective detection of metal ions, inorganic ions and biomolecules in food, soil, water and biological samples. The past few years have witnessed the development of many successful strategies for the preparation of numerous protein-Au NC-based sensing systems. In this review, we focus on a number of sensing systems based on protein-Au NCs for the detection of various analytes of interest with a special emphasis on their corresponding sensing mechanisms. [ABSTRACT FROM AUTHOR]

Nitric oxide (NO) is an important signaling molecule in biology. Both NO excess and insufficiency have been implicated in numerous physiological and pathological conditions. In order to study the diverse biological roles of NO in cells and tissues, many techniques have been developed for assaying NO. Recently, new generations of fluorescent probes have become indispensible tools for the study of NO biology because of their sensitivity, selectivity, spatiotemporal resolution, and experimental feasibility. Rational application of these probes in the study requires the understanding of the molecular mechanism that the probes are involved in. In this review, we will present an arsenal of fluorescent probes used to detect NO in living cells and animal tissues. We will also discuss the molecular mechanisms, actualities and prospects of fluorescent probes in detecting NO in cell biology. [ABSTRACT FROM AUTHOR]

Highly photoluminescent carbon nanoparticles with a quantum yield of 37.40% were directly synthesized by a simple hydrothermal treatment of oatmeal in pure water without using any surface passivation and oxidizing agents. Due to the bright fluorescence, high photo-stability, low toxicity and good biocompatibility, the as-prepared carbon nanoparticles are demonstrated to be excellent probes in bio-imaging. [ABSTRACT FROM AUTHOR]

In this paper, mechanically strong organic–inorganic nanocomposite (NC) gradient hydrogels were successfully prepared by the in situ polymerization of acrylamide (Am) and N,N-dimethyl aminoethyl methacrylate (DMAEMA) using an electrophoresis method. Due to its specific colloidal properties, LAPONITE® showed directional movement in direct-current (DC) electric field and thus formed a gradient distribution in the hydrogel. The concentration gradient of LAPONITE® was characterized by UV-vis absorption, FTIR and TGA. The network structures of lyophilized gradient hydrogels were observed from SEM images. The TEM morphology indicated that LAPONITE® had a good gradient dispersion in the NC gradient hydrogel. As a physical crosslinker, LAPONITE® can regulate the cross-linking density of the hydrogel, thus affecting its mechanical properties. The NC gradient hydrogel exhibited a high mechanical strength (a gradient tensile strength ranging from 43.4 to 135.3 kPa and a gradient compression strength ranging from 116 kPa to 1100 kPa, depending on the distance from the anode). This work provided a facile method to develop NC gradient hydrogels with improved mechanical performance. The NC gradient hydrogels can be used as potential candidates in the field of biological and chemical materials. [ABSTRACT FROM AUTHOR]

To enhance the photocatalytic properties of coordination complex modified polyoxometalates (CC/POMs) in the visible light region, its nanobelts (CC/POMNBs) were loaded on activated carbon fiber (ACF) through a simple colloidal blending process. The resulting coordination complex modified polyoxometalate nanobelts loaded activated carbon fiber composite materials (CC/POMNBs/ACF) exhibited dramatic photocatalytic activity for the degradation of rhodamine B (RhB) under visible light irradiation. Optical and electrochemical methods illustrated the enhanced photocatalytic activity of CC/POMNBs/ACF, which originates from the high separation efficiency of the photogenerated electrons and holes on the interface of the CC/POMNBs and ACF, which results from the synergistic effects between them. In the composite material, the role of ACF could be described as a photosensitizer and a good electron transporter. Furthermore, the influence of the mass ratio between the CC/POMNBs and ACF on the photocatalytic performance of the resulting composite material was discussed, and an ideal value to obtain highly efficient photocatalysts was obtained. The results suggested that the loading of CC/POMNBs on the surface of ACF would be a feasible strategy to enhance their photocatalytic activity. [ABSTRACT FROM AUTHOR]

Bifunctional Ag2S QDs@CS-RBS nanospheres with ultralow toxicity for biomedical use were fabricated. These are capable of releasing NO under irradiation of visible light and emitting in near-infrared (NIR) region fluorescence excited by NIR laser under physiological environment. Glutathiose (GSH)-capped Ag2S QDs were synthesized and encapsulated by chitosan (CS) to form NIR fluorescent Ag2S QDs@CS nanospheres. A type of iron/sulfur/-nitrosyl cluster, Roussin's black salt anion Fe4S3(NO)7− (RBS) was conjugated with the Ag2S QDs@CS to obtain Ag2S QDs@CS-RBS nanospheres. A variety of characterization methods were employed to analyze the nanospheres. In vitro cell imaging and in vivo mice imaging experiments demonstrated that the Ag2S QDs@CS-RBS nanospheres could emit readily observable NIR fluorescence and deliver NO in living cells and small animals. The NIR imaging of the Ag2S QDs@CS nanospheres would not interfere with the light-triggered NO release from them, as the excitation lasers needed for these two functions are in different wavelength regions. This work provides new perspectives for the application of multifunctional nano-structured materials in diagnostics and bioimaging. [ABSTRACT FROM AUTHOR]

A new strategy toward controllable release of NO for therapeutic purpose is described. Mn2+-doped ZnS quantum dots with NIR-II to visible upconversion properties were encapsulated by chitosan, with which photochemical NO precursors were conjugated to generate nanostructured materials capable of releasing NO under NIR-II irradiation. [ABSTRACT FROM AUTHOR]

High quality CdS nanocrystals emitting from 412 to 458 nm were synthesized by a simple one-pot noninjection microwave irradiation route using low-cost, air-stable CdO, S powder, 1-octadecene and oleic acid as the starting materials under air atmosphere. With simple variation of the reaction recipe (growth temperature and time), the absorption and emission wavelength, full width at half maximum (FWHM), and crystalline size of the resulting CdS quantum dots (QDs) can be conveniently tuned. The quantum yield of the as-prepared QDs at 240 °C for 30 min can be up to 33%. Compared with the traditional hot-injection approach, QDs synthesized by microwave heating are more efficient and the shortening of the reaction time leads to a high reaction yield. The use of microwave allows for a highly reproducible and effective synthesis protocol that is fully adaptable for mass production and can be easily employed to synthesize a variety of metal sulfide QDs. [ABSTRACT FROM AUTHOR]

A new CuFL (2-{2-chloro-6-hydroxy-5-[(2-methyl-quinolin-8-ylamino)-methyl]-3-oxo-3H-xanthen-9-yl}-benzoic acid)–CS (chitosan) NS diazeniumdiolates system consisting of NO donors and highly-sensitive NO probes is reported. FL–CS NS diazeniumdiolates were synthesized by incorporating the fluorescent molecule FL with chitosan (CS) and reacting the resultant FL–CS complex with pressurized NO and dimethyl sulfate (DMS). Then the FL–CS NS diazeniumdiolates were reacted with copper chloride (CuCl2) to generate non-fluorescent CuFL–CS NS diazeniumdiolates. The CuFL–CS NS diazeniumdiolates have a spherical outline with a dimension of ca. 250 nm. They have high selectivity for NO over other related substances. The results of in vitro and in vivo experiments indicate that the CuFL–CS NS diazeniumdiolates can release NO under physiological conditions and meanwhile detect the released NO based on the considerable fluorescence increase of the otherwise non-fluorescent system caused by the NO. The good fluorescence stability of the NO–FL–CS NS provides prospects for the CuFL–CS NS diazeniumdiolates in biomedical applications. [ABSTRACT FROM AUTHOR]

Novel highly luminescent Cu+ doped CdS quantum dots (QDs) were directly synthesized in aqueous phase through a facile single-step noninjection method. Due to their bright red fluorescence, ultrasmall size, and good biocompatibility, as-prepared CdS:Cu+ QDs have potential as probes in bio-imaging. [ABSTRACT FROM AUTHOR]

Zinc ion batteries (ZIBs) have attracted extensive attention for their high safety and environmentally friendly nature, and considerable theoretical capacities. Due to its unique two-dimensional layered structure and high theoretical specific capacities, molybdenum disulfide (MoS 2 ) presents as a promising cathode material for ZIBs. Nevertheless, the low electrical conductivity and poor hydrophilicity of MoS 2 limits its wide application in ZIBs. In this work, MoS 2 /Ti 3 C 2 T x composites are effectively constructed using a one-step hydrothermal method, where two-dimensional MoS 2 nanosheets are vertically grown on monodisperse Ti 3 C 2 T x MXene layers. Contributing to the high ionic conductivity and good hydrophilicity of Ti 3 C 2 T x , MoS 2 /Ti 3 C 2 T x composites possess improved electrolyte-philic and conductive properties, leading to a reduced volume expansion effect of MoS 2 and accelerated Zn 2+ reaction kinetics. As a result, MoS 2 /Ti 3 C 2 T x composites exhibit high voltage (1.6 V) and excellent discharge specific capacity of 277.8 mA h g -1 at 0.1 A g -1 , as well as cycle stability as cathode materials for ZIBs. This work provides an effective strategy for developing cathode materials with high specific capacity and stable structure., Competing Interests: There are no conflicts of interest., (This journal is © The Royal Society of Chemistry.)

Construction of a heterojunction between quantum dots and TiO 2 nanowire arrays via electrostatic self-assembly is rarely reported. In this work, mercury lamp irradiation was used to change the surface potential of WO 3 quantum dots and TiO 2 nanowire arrays, resulting in WO 3 quantum dots tightly attached on the surface of TiO 2 nanowire through electrostatic self-assembly. Photoelectrochemical measurements showed that the WO 3 quantum dots formed a type II heterojunction with the TiO 2 nanowire arrays rather than serving as carrier-trapping sites. In the self-assembly system, the TiO 2 nanowire arrays provide a charge-transfer channel for the WO 3 quantum dots, greatly improving the contribution of the WO 3 quantum dots to the photocurrent. Quantitative calculations showed that the improvement of the bulk carrier-separation efficiency was the reason for the enhanced photoelectrochemical performance of the self-assembled system. The photocurrent density of the optical self-assembled system at 1.23 V ( vs. RHE) was ∼5.5 times as high as that of the TiO 2 nanowire arrays. More importantly, the self-assembled system exhibited excellent photoelectrochemical stability.

Catheter-associated urinary tract infections are one of the most common hospital-acquired infections. Encrustation formation results from infection of urease-producing bacteria and further complicates the situation. A typical sign of the initial onset of encrustation formation is the alkalization of the urine (pH up to 9-10). However, effective antibacterial strategies with high antimicrobial loading efficiency and pH-responsiveness of antimicrobial release are still lacking. In this study, we developed a poly(sulfobetaine methacrylate)-tannic acid (polySBMA-TA) hydrogel coating, which served as a universal, efficient, and responsive carrier for antimicrobials on urinary catheters. Common antimicrobials, including poly(vinylpyrrolidone)-iodine, copper ions, and nitrofurazone were loaded into the polySBMA-TA coating in high efficiency (several fold higher than that of the polySBMA coating), via the formation of multiple non-covalent interactions between the antimicrobials and hydrogel coating. The hydrogel coatings maintained good antibacterial properties under neutral conditions. More importantly, the pH-responsive release of antibacterial agents under alkaline conditions further enhanced the antibacterial activity of the coatings, which was advantageous for killing the urease-producing bacteria and preventing encrustation. In vitro and in vivo tests confirmed that the hydrogel coating has good biocompatibility, and could effectively inhibit bacterial colonization and encrustation formation. This study offers new opportunities for the utilization of a simple and universal antimicrobial-loaded hydrogel coating with smart pH-responsive properties to combat bacterial colonization and encrustation formation in urinary catheters.

Photodeposition of dual-cocatalysts Pt-Cr or Rh-Cr on the surface of ZnIn 2 S 4 is used to achieve overall water splitting. Compared with the hybrid loading of the Pt element and Cr element, the formation of the Rh-S bond results in space separation of the Rh element and Cr element. The Rh-S bond and space separation of cocatalysts promote the transfer of bulk carriers to the surface and inhibit self-corrosion.

A series of complexes L22-M (L2: 6,6″-bis(4-methoxyphenyl)-4'-phenyl-2,2':6',2″-terpyridine, M: Mn 2+ , Fe 2+ , Co 2+ , Ni 2+ , Cu 2+ , Zn 2+ ) were synthesized by coordinating p -methoxyphenyl 6,6″-substituted terpyridine ligand with first-row transition metal ions and characterized by NMR, ESI-MS, and X-ray single crystal diffraction techniques. Single-crystal structures demonstrated that the steric hindrance of p -methoxyphenyl substituents endowed complexes L22-M with obvious longer coordination bond lengths and larger bond angles and dihedral angles compared with unmodified L12-M (L1: 4'-phenyl-2,2':6',2″-terpyridine). The chiral helix geometry was observed for L22-M, in which 2,2':6',2″-terpyridine moiety dramatically twisted to a spiral form in comparison to the nearly coplanar structure of the parent L12-M, resulting in plentiful intramolecular and intermolecular π-π interactions. Also, the appealing racemic (P and M) double helix packed structure for 6,6″-modified bisterpyridine complex L22-Cu was formed in the crystal. The consequent appealing charge transfer (CT) emission for L22-Zn in the solution and solid were investigated via UV-vis and fluorescence spectroscopy techniques and time-dependent density functional theory (TD-DFT) calculations. This work afforded a new method to achieve intriguing chiral geometry and CT optical properties via the subtle design and modification of terpyridine ligands.

To enhance the photocatalytic properties of coordination complex modified polyoxometalates (CC/POMs) in the visible light region, its nanobelts (CC/POMNBs) were loaded on activated carbon fiber (ACF) through a simple colloidal blending process. The resulting coordination complex modified polyoxometalate nanobelts loaded activated carbon fiber composite materials (CC/POMNBs/ACF) exhibited dramatic photocatalytic activity for the degradation of rhodamine B (RhB) under visible light irradiation. Optical and electrochemical methods illustrated the enhanced photocatalytic activity of CC/POMNBs/ACF, which originates from the high separation efficiency of the photogenerated electrons and holes on the interface of the CC/POMNBs and ACF, which results from the synergistic effects between them. In the composite material, the role of ACF could be described as a photosensitizer and a good electron transporter. Furthermore, the influence of the mass ratio between the CC/POMNBs and ACF on the photocatalytic performance of the resulting composite material was discussed, and an ideal value to obtain highly efficient photocatalysts was obtained. The results suggested that the loading of CC/POMNBs on the surface of ACF would be a feasible strategy to enhance their photocatalytic activity.

ZnO-NaSrBO3:Tb(3+) (ZNT) composites were successfully synthesized via microwave-assisted reaction of the ZnO precursor with a NaSrBO3:Tb(3+) suspension using a microwave synthesis system. The morphology, structure and photocatalytic performance in the degradation of methylene blue (MB) were characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy, fluorescence spectrophotometry and electrochemical impedance spectroscopy, respectively. The results show that the ZNT composites exhibit enhanced photocatalytic activity in the degradation of MB with a maximum degradation rate of 97% under visible light irradiation compared with pure ZnO (12%), which is ascribed to the increased light absorption and the reduction of photoelectron-hole pair recombination in ZnO with the introduction of NaSrBO3:Tb(3+), as well as the light down-converting effect of NaSrBO3:Tb(3+), which facilitates the self-sensitized degradation of MB.

Mn(2+) doped-AlN red phosphors were prepared by the solid-state reaction method. X-ray diffraction, SEM-EDS, photoluminescence and cathodoluminescence were utilized to characterize the prepared phosphor. Under UV light or electron beam excitation, the AlN:Mn(2+) phosphors exhibit a strong red emission centered at 600 nm, which is ascribed to the characteristic (4)T1((4)G)-(6)A1((6)S) transition of Mn(2+). Energy level diagrams were constructed to discuss the photoluminescence and cathodoluminescence processes of the AlN:1% Mn(2+) phosphor. The oxygen-related defects in AlN have great influence on the photoluminescence and cathodoluminescence properties of the AlN:1% Mn(2+) phosphor. The dependence of brightness on accelerating voltage or electric current, the decay behavior of CL intensity under the electron bombardment, and the stability of CIE chromaticity coordinates were investigated in detail. The results indicate that the AlN:Mn(2+) phosphor exhibits a higher brightness, higher color purity, and lower saturation compared to the red Y2O3:Eu(3+) phosphor, which gives the AlN:Mn(2+) phosphor great potential as a red phosphor for full color FEDs.

Novel highly luminescent Cu(+) doped CdS quantum dots (QDs) were directly synthesized in aqueous phase through a facile single-step noninjection method. Due to their bright red fluorescence, ultrasmall size, and good biocompatibility, as-prepared CdS:Cu(+) QDs have potential as probes in bio-imaging.

Y(3)Al(5)O(12):Ce phosphors have been prepared and used as an effective scattering layer on top of a transparent layer of nanocrystalline TiO(2) for dye sensitized solar cells (DSSCs). The Y(3)Al(5)O(12):Ce scattering layer increases the photocurrent of DSSCs due to the enhanced light harvesting mainly via the improved light absorption and scattering. Under one sun illumination (AM 1.5G, 100 mW cm(-2)), a high efficiency of 7.91% was achieved for the cell with a Y(3)Al(5)O(12):Ce scattering layer, which is an increase of 13.5% compared to the cell without a scattering layer (6.97%)., (This journal is © The Royal Society of Chemistry 2012)