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CsPbIxBry-based all-inorganic perovskite materials are a potential candidate for stable semitransparent and tandem structured photovoltaic devices. However, poor film (morphological and crystalline...

Herein, we have synthesized a series of hexaphenylbenzene (HPB) derivatives: HPB-H, HPB-COOCH3 and HPB-COOH that differs in functional groups attached to the periphery of the outer benzene rings. Among them, the HPB with carboxyl functional group (HPB-COOH) as LIB anode shows a superior capacity of 997.4 mAh g−1 and better rate performance than HPB and HPB-COOCH3. Such superior anode properties can be attributed to the fact that HPB-COOH has a layered morphology, a pseudo-2D structure, lower LUMO energy, and higher electron conductivity, compared with that of HPB-COOCH3 and HPB-H, respectively. Moreover, low energy packing with transport channels is beneficial for Li ions diffusion during the lithiation and extraction processes. Furthermore, HPB-COOH shows excellent cycling stability presumably due to its layered molecular packing structures. Our work paves the way for the design synthesis of novel organic molecules with suitable electrochemical redox-active groups and layered hierarchical structure to achieve high capacity, good rate performance, and high cyclic stability for next generation Li ion batteries (LIBs).

Low-work-function (WF) metals (including silver (Ag), aluminum (Al), and copper (Cu)) used as external cathodes in inverted perovskite solar cells (PSCs) encounter oxidation caused by air exposure and halogen-diffusion-induced corrosion, which threaten the long-term stability of the device. The cathode interlayer (CIL) has shown promise in reducing the metal WF and thus boosting the device power conversion efficiency (PCE). However, it remains a challenge for current CIL materials to enable high-WF metals (e.g., Au) to be used as cathodes to achieve PSCs with a superior PCE and long-term stability. Here, we use a series of synthesized (carbolong-derived) organometallic complexes as CILs to tune the electrode WF in inverted PSCs. Density functional theory calculations and surface characterizations show that the organometallic complexes that contain anions and cations are prone to form anion-cation dipoles on the metal surface, hence drastically reducing the metal's WF. Photovoltaic devices based on a Ag cathode, which was modified with these organometallic complexes, received a boosted PCE up to 21.29% and a remarkable fill factor that reached 83.52%, which are attributed to the dipole-enhanced carrier transport. The environmental stability of PSCs was further improved after employing Au as a cathode with these organometallic complexes, and the modified devices exhibited no efficiency loss after 4080 h storage measurements.

The exploration of efficient oxygen reduction reaction (ORR) electrocatalysts with low-cost and facile process is crucial for the commercialization of fuel cells and metal–air batteries. Herein, we demonstrate a template-free strategy to synthesize N-doped porous carbon spheres (NPCS-X, X denotes the pyrolysis temperature) composed of nanosheets via pyrolysis of self-assembled urea formaldehyde (UF) resin as a single precursor. The resultant NPCS-900 exhibits an outstanding electrocatalytic activity towards ORR with a half-wave potential (E1/2) of 0.87 V (vs. RHE), superior long-term stability and methanol resistance compared with the commercial Pt/C catalyst in alkaline solution. Furthermore, NPCS-900 also has an impressive ORR electrocatalytic activity and durability in an acid electrolyte. The excellent electrochemical performance of NPCS-900 can be attributed to the abundant exposed active sites of N-species and carbon defects distributed throughout the porous carbon nanosheets of NPCS-900.

Designing a structurally stable anode with a high reversible capacity for sodium ion batteries (SIBs) is particularly crucial so that batteries are able to meet the requirements for large-scale applications in grid electrical energy storage. Polyaromatic hydrocarbons (PAHs) are organic molecules with well-defined structures that demonstrate excellent performance in lithium storage. Based on our well-established correlation between battery property and molecular structure, for the first time, we applied a recently synthesized hexabenzocoronene (HBC) and corresponding derivate HBC–OMe to engage in sodium storage. The HBC molecule forms self-assemblies with a long-range ordered face-center cubed (fcc) structure due to the interaction between two HBC moieties. Such a unique 3D structure is expected to generate a strong π–π interaction between flakes and thus yield amazing durability during the long-term cycling process. In addition, the surface-dominated Na+ storage mechanism can facilitate the Na+ transport kinetics and simultaneously alleviate the structural strain during charging–discharging cycles. Benefiting from the coupling effect of the surface-driven capacitive process and the robust 3D self-assembled hierarchical nature, an oxygen-containing sample, HBC–OMe, exhibited an extraordinary sodium storage capability, attaining a high capacity of 506 mA h g−1 at 0.1 A g−1 with excellent rate capability (217 mA h g−1 at 5 A g−1) and superior long-term cycling performance (290 mA h g−1 at 2 A g−1 with negligible capacity fade after 1000 cycles).

Green and sustainable electrochemical conversion and storage devices possess the nature to repress a negative effect on sustainability during energy conversion and storage. However, the sustainabil...

The combination of ferroelectric–optical properties in halide perovskites has attracted tremendous interess because of its potential for optoelectronic and energy applications. However, very few re...

Organic carbon materials, such as graphene and nanotubes, with a high specific capacity show promise in improving the energy density for lithium ion batteries (LiBs). Here, we report on the synthesis and characterization of C60(OH)12 and the C60(OH)12/graphene oxide (GO) composite and demonstrate their use as anode materials in LiBs. We find that the C60(OH)12/GO composite forms due to the chemical reactions between the carboxyl and epoxy groups of GO and the hydroxyl of C60(OH)12 nanoparticles and that C60(OH)12 uniformly grows on the surface of GO nanosheets. Using a suite of spectroscopy probes, we unequivocally show the mixing between C60(OH)12 and GO at the molecular level, which leads to superior battery performances. This composite has a reversible capacity of 1596 mAh g-1 at 0.2 A g-1, higher than the capacities of C60(OH)12 and GO. This composite has a superior cycling stability and excellent rate performance, making it a promising organic anode material for high-performance LiBs.

Graphene fibres have been recognized as ideal building blocks to make advanced, macroscopic, and functional materials for a variety of applications. Direct fabrication of graphene fibres with ideal graphene sheets is still far from reality due to the weak intermolecular bonding between graphene sheets. In contrast, the construction of graphene oxide fibres by following a reduction process is a common compromise. The self-assembly of graphene oxide is an effective strategy for the continuous fabrication of graphene fibre. Different fabrication strategies endow graphene fibres with different performances. Over the past decade, various studies have been carried out into integrating graphene oxide nanosheets into graphene fibres. In this review, we summarize the assembly methods of graphene fibres and compare the mechanical and electrical performances of the graphene fibres fabricated by different strategies. Also the influence of the fabrication strategy on mechanical performance is discussed. Finally, the expectation of macroscopic graphene fibres in the future is further presented.

Traditional preparation of ZnO nanocrystal requires heating zinc acetate to a temperature over 350 °C, whereas in this work, zinc acetate was first electrospun with PVDF to form a nanofiber, followed by thermal treatment at only 140 °C to give nanocrystalline ZnO. The much lower temperature required in thermal treatment is attributed to the high reactivity of zinc acetate at nano dimension. The as-prepared ZnO-doped PVDF nanofiber mat shows excellent effect in the photocatalytic degradation of Rhodamine B, comparable to ZnO particle thermally treated at 600 °C. Highly-oriented ZnO nanorods were obtained by further hydrothermal synthesis of the electrospun nanofiber mat, giving nanostructured ZnO of different morphologies well-aligned on the surface of organic nanofiber. Notably, the hydrothermal synthesis of the successful preparation of these nanostructured ZnO requires a processing temperature below 100 °C at atmospheric pressure, showing great potential to be scaled up for vast manufacturing.

Renewable organic cathodes with abundant elements show promise for sustainable rechargeable batteries. Herein, for the first time, utilizing C60 fullerene as organic cathode for room‐temperature lithium‐ion battery is reported. The C60 cathode shows robust electrochemical performance preferably in ether‐based electrolyte. It delivers discharge capacity up to 120 mAh g−1 and specific energy exceeding 200 Wh kg−1 with high initial Coulombic efficiency of 91%. The as‐fabricated battery holds a capacity of 90 mAh g−1 after 50 cycles and showcases remarkable rate performance with 77 mAh g−1 retained at 500 mA g−1. Noteworthily, three couples of unusual flat voltage plateaus recur at ≈2.4, 1.7, and 1.5 V, respectively. Diffusion‐dominated three‐electron‐redox reactions are revealed by cyclic voltammogram and plateau capacities. Intriguingly, it is for the first time unveiled by in situ X‐ray diffraction (XRD) that the C60 cathode underwent three reversible phase transitions during lithiation/delithiation process, except for the initial discharge when irreversible polymerization in between C60 nanoclusters existed as suggested by the characteristic irreversible peak shifts in both in situ XRD pattern and in situ Raman spectra. Cs‐corrected transmission electron microscope corroborated these phase evolutions. Importantly, delithiation potentials derived from density‐functional‐theory simulation based on proposed phase structures qualitatively consists with experimental ones., Renewable C60 fullerene is for the first time applied as organic cathode for room‐temperature Li‐ion battery, showcasing unusual electrochemical performance. Unlike previously reported cases, the voltage profiles of C60 fullerene in this study unusually exhibit three flat plateaus, corresponding to three‐electron‐transfer. Further, three reversible phase transitions are revealed by in situ XRD, ex situ TEM, and DFT calculations.

Sarcosine is a recently identified biomarker for prostate cancer. However, the rapid detection methods for sarcosine are relatively lack because of the low concentration and the presence of complicated interfering substances in serum or urine. In this manuscript, hollow nanospheres of Fe3O4 was synthesized and used as carrier to disperse Pt (Pt) nanoparticles. In order to achieve excellent electron transfer ability, we use polyaniline to coat Pt–Fe3O4 nanoparticles, and pyrolyze the polyaniline to carbon (C). Thus, hollow magnetic Pt–Fe3O4@C nanocomposites with good electron transfer ability are formed. The Pt–Fe3O4@C nanocomposites have high catalytic activity and stability. The nanocomposites were immobilized on glassy carbon electrode (GCE) to construct a nonenzyme hydrogen peroxide (H2O2) sensor (Pt–Fe3O4@C/GCE). We further construct a sensitive sarcosine biosensor by immobilizing sarcosine oxidase (SOx) on the Pt–Fe3O4@C/GCE. The high catalytic activity and good biocompatibility of Pt–Fe3O4@C nanocomposites greatly retained the bioactivity of immobilized SOx, and the prepared sarcosine biosensor has good electrocatalytic performance towards sarcosine. It has a linear detection range between 0.5 and 60 μM with a limit of detection (LOD) of 0.43 μM (the signal to noise ratio is 3), and the sensitivity is 3.45 nA μM−1 (48.8 nA μM−1 cm−2), which has the potential to be used for rapid screening of prostate cancer.

Exploiting platinum-group-metal (PGM)-free electrocatalysts with remarkable activity and stability toward oxygen reduction reaction (ORR) is of significant importance to the large-scale commercialization of proton exchange membrane fuel cells (PEMFCs). Here, a high-performance and anti-Fenton reaction cobalt-nitrogen-carbon (Co-N-C) catalyst is reported via employing double crosslinking (DC) hydrogel strategy, which consists of the chemical crosslinking between acrylic acid (AA) and acrylamide (AM) copolymerization and metal coordinated crosslinking between Co2+ and P(AA-AM) copolymer. The resultant DC hydrogel can benefit the Co2+ dispersion via chelated Co-N/O bonds and relieve metal agglomeration during the subsequent pyrolysis, resulting in the atomically dispersed Co-Nx/C active sites. By optimizing the ratio of AA/AM, the optimal P(AA-AM)(5-1)-Co-N catalyst exhibits a high content of nitrogen doping (12.36 at%) and specific surface area (1397 m2 g-1 ), significantly larger than that of the PAA-Co-N catalyst (10.59 at%/746 m2 g-1 ) derived from single crosslinking (SC) hydrogel. The electrochemical measurements reveal that P(AA-AM)(5-1)-Co-N possesses enhanced ORR activity (half-wave potential (E1/2 ) ≈0.820 V versus the reversible hydrogen electrode (RHE)) and stability (≈4 mV shift in E1/2 after 5000 potential cycles in 0.5 m H2 SO4 at 60 oC) relative to PAA-Co-N, which is higher than most Co-N-C catalysts reported so far.

Inspired by the structural advantages of spiro-OMeTAD, which is the most commonly used hole-transporting material (HTM), two rationally designed HTMs with butterfly-shaped triarylamine groups based on dibenzofulvene-bridged indacenodithiophene (IDT) core (attaching hexyl and octyl chains) have been synthesized, namely, IT-C6 and IT-C8, respectively. Shorter alkyl-chain-based IT-C6 exhibits a marked increase in glass-transition temperature (Tg) of 105 °C, whereas IT-C8 shows a Tg of 95 °C. Moreover, it is demonstrated that IT-C6 exhibits a higher hole-transporting mobility, more suitable band energy alignment, better interfacial contact, and passivation effect. The inverted devices of employed HTM based on IT-C6 obtained a champion PCE of 18.34% with a remarkable fill factor (FF) of 82.32%, whereas the IT-C8-based device delivered an inferior PCE of 16.94% with an FF up to 81.20%. Both HTMs embodied inverted devices present high FF values greater than 81%, which are among the highest reported values of small molecular HTM-based PSCs. This work reveals that cutting off the symmetrical spiro-core and subsequently combining IDT (attaching tailored alkyl chains) with the spiro-linkage fluorine to construct the orthogonal molecular conformation is a significant principle for the design of promising dopant-free HTMs.

Biopolymer-based optical hydrogels represent an emerging class of materials with potential applications in biocompatible integrated optoelectronic devices, bioimaging applications, and stretchable/flexible photonics. We have synthesized stimuli-responsive three-dimensional hydrogels from genetically engineered elastin-like polymers (ELPs) and have loaded these hydrogels with an amine-containing p-phenylenevinylene oligomer (OPPV) derivative featuring highly tunable, environmentally sensitive optical properties. The composite ELP/OPPV hydrogels exhibit both pH- and temperature-dependent fluorescence emission, from which we have characterized a unique optical behavior that emerged from OPPV within the hydrogel environment. By systematic comparison with free OPPV in solution, our results suggest that this distinct behavior is due to local electronic effects arising from interactions between the hydrophobic ELP microenvironment and the nonprotonated OPPV species at pH 7 or higher.

It is of great importance to develop highly efficient and stable Pt-free catalysts for electrochemical hydrogen generation from water electrolysis. Here, monodisperse 7.5 nm copper-doped ruthenium hollow nanoparticles (NPs) with abundant defects and amorphous/crystalline hetero-phases were prepared and employed as efficient hydrogen evolution electrocatalysts in alkaline electrolyte. Specifically, these NPs only require a low overpotential of 25 mV to achieve a current density of 10 mA cm-2 in 1.0 M KOH and show acceptable stability after 2000 potential cycles, which represents one of the best Ru-based electrocatalysts for hydrogen evolution. Mechanism analysis indicates that Cu incorporation can modify the electronic structure of Ru shell, thereby optimizing the energy barrier for water adsorption and dissociation processes or H adsorption/desorption. Cu doping paired with the defect-rich and highly open hollow structure of the NPs greatly enhances hydrogen evolution activity.

In this work, monodisperse core/shell Cu/In2O3 nanoparticles (NPs) were developed to boost efficient and tunable syngas formation via electrochemical CO2 reduction for the first time. The efficiency and composition of syngas production on the developed carbon-supported Cu/In2O3 catalysts are highly dependent on the In2O3 shell thickness (0.4–1.5 nm). As a result, a wide H2/CO ratio (4/1 to 0.4/1) was achieved on the Cu/In2O3 catalysts by controlling the shell thickness and the applied potential (from −0.4 to −0.9 V vs reversible hydrogen electrode), with Faraday efficiency of syngas formation larger than 90%. Specifically, the best-performing Cu/In2O3 catalyst demonstrates remarkably large current densities under low overpotentials (4.6 and 12.7 mA/cm2 at −0.6 and −0.9 V, respectively), which are competitive with most of the reported systems for syngas formation. Mechanistic discussion implicates that the synergistic effect between lattice compression and Cu doping in the In2O3 shell may enhance the bindi...

In this work, the three-dimensional nitrogen-doped nanostructured carbons with hierarchical architectures (3D-NNCsHAs) with high density of defective sites, high surface area and pluralities of pore size distributions was prepared through the pyrolysis of sea-tangle (Laminaria japonica), an inexpensive, eco-friendly and abundant precursor. Benefitting from their structural uniqueness, a selective and sensitive ascorbic acid (AA) sensor based on 3D-NNCsHAs was developed. Compared to the glassy carbon electrode (GCE) and the carbon nanotubes modified GCE (CNTs/GCE), the 3D-NNCsHAs modified GCE (3D-NNCsHAs/GCE) presents higher performance towards the electrocatalysis and detection of AA, such as lower detection limit (1 μM), wider linear range (10–4410 μM) and lower electrooxidation peak potential (−0.02 V vs. Ag/AgCl). In addition, 3D-NNCsHAs/GCE also exhibits high anti-interference and anti-fouling abilities for AA detection. Particularly, the fabricated 3D-NNCsHAs/GCE is able to determine AA in real samples and the results acquired are satisfactory. Therefore, the 3D-NNCsHAs can be considered as a kind of novel electrode nanomaterial for the fabrication of selective and sensitive AA sensor for the extensive practical applications ranging from food analysis, to pharmaceutical industry and clinical test.

Protein-ligand conjugations are usually carried out in aqueous media in order to mimic the environment within which the conjugates will be used. In this work, we focus on the conjugation of amphiphilic variants of elastin-like polypeptide (ELP), short elastin (sEL), to poorly water-soluble compounds like OPPVs ( p-phenylenevinylene oligomers), triarylamines, and polypyridine-metal complexes. These conjugations are problematic when carried out in aqueous phase because hydrophobic ligands tend to avoid exposure to water, which in turn causes the ligand to self-aggregate and/or interact noncovalently with hydrophobic regions of the amphiphile. Ultimately, this behavior leads to low conjugation efficiency and contamination with strong noncovalent "conjugates". After exploring the solubility of sEL in various organic solvents, we have established an efficient conjugation methodology for obtaining covalent conjugates virtually free of contaminating noncovalent complexes. When conjugating carboxylated ligands to the amphiphile amines, we demonstrate that even when only one amine (the N-terminus) is present, its derivatization is 98% efficient. When conjugating amine moieties to the amphiphile carboxyls (a problematic configuration), protein multimerization is avoided, 98-100% of the protein is conjugated, and the unreacted ligand is recovered in pure form. Our syntheses occur in "one pot", and our purification procedure is a simple workup utilizing a combination of water and organic solvent extractions. This conjugation methodology might provide a solution to problems arising from solubility mismatch of protein and ligand, and it is likely to be widely applied for modification of recombinant amphiphiles used for drug delivery (PEG-antibodies, polymer-enzymes, food proteins), cell adhesion (collagen, hydrophobins), synthesis of nanostructures (peptides), and engineering of biocompatible optoelectronics (biological polymers), to cite a few.

For the first time, we report that graphene oxide (GO) can be used as a new “dual-role” binder for Si nanoparticles (SiNPs)-based lithium-ion batteries (LIBs). GO not only provides a graphene-like porous 3D framework for accommodating the volume changes of SiNPs during charging/discharging cycles, but also acts as a polymer-like binder that forms strong chemical bonds with SiNPs through its Si–OH functional groups to trap and stabilize SiNPs inside the electrode. Leveraging this unique dual-role of GO binder, we fabricated GO/SiNPs electrodes with remarkably improved performances as compared to using the conventional polyvinylidene fluoride (PVDF) binder. Specifically, the GO/SiNPs electrode showed a specific capacity of 2400 mA h g–1 at the 50th cycle and 2000 mA h g–1 at the 100th cycle, whereas the SiNPs/PVDF electrode only showed 456 mAh g–1 at the 50th cycle and 100 mAh g–1 at 100th cycle. Moreover, the GO/SiNPs film maintained its structural integrity and formed a stable solid–electrolyte interphase...

For the first time, the carbon nanoplates with high density of defective sites derived from the biomass of ground cherry (Physalis peruviana) husks was synthesized for the construction of an advanced electrochemical sensing platform. Electrochemical responses of different molecules (potassium ferricyanide, β-nicotinamide adenine dinucleotide, hydrogen peroxide, epinephrine and dopamine, the mixture of four free DNA bases (guanine, thymine, cytosine and adenine), cysteine, ascorbic acid, L-tryptophan, uric acid and acetaminophen) were studied at the biomass derived ground cherry husks derived carbon nanoplates (BG-CNPs) modified glassy carbon (GC) (BG-CNPs/GC) electrode, which shows higher electrocatalytic activities than GC electrode. Especially, the BG-CNPs/GC electrode exhibits remarkably strong electrocatalytic response toward hydrogen peroxide (H2O2) compared with carbon nanotubes modified GC (CNTs/GC) and GC electrodes, indicating the great potential feasibility in the detection of H2O2 in human urine as well as the monitoring of H2O2 released from the living cells. All the results indicate that BG-CNPs is a promising carbon material which could be utilized to develop an advanced electrochemical sensing platform with multifunctional applications ranging from voltammetric sensing to amperometric sensing and DNA sensing.

An effective and universal strategy is developed to enhance the stability of the non-noble-metal M-Nx /C catalyst in proton exchange membrane fuel cells (PEMFCs) by improving the bonding strength between metal ions and chelating polymers, i.e., poly(acrylic acid) (PAA) homopolymer and poly(acrylic acid-maleic acid) (P(AA-MA)) copolymer with different AA/MA ratios. Mossbauer spectroscopy and X-ray absorption spectroscopy (XAS) reveal that the optimal P(AA-MA)-Fe-N catalyst with a higher Fe3+ -polymer binding constant possesses longer FeN bonds and exclusive Fe-N4 /C moiety compared to PAA-Fe-N, which consists of ≈15% low-coordinated Fe-N2 /N3 structures. The optimized P(AA-MA)-Fe-N catalyst exhibits outstanding ORR activity and stability in both half-cell and PEMFC cathodes, with the retention rate of current density approaching 100% for the first 37 h at 0.55 V in an H2 -air fuel cell. Density functional theory (DFT) calculations suggest that the Fe-N4 /C site could optimize the difference between the adsorption energy of the Fe atoms on the support (Ead ) and the bulk cohesive energy (Ecoh ) relative to Fe-N2 /N3 moieties, thereby strongly stabilizing Fe centers against demetalation.

Here, we report that spherical C60 derivatives with well-defined molecular structures hold great promise to be advanced anode materials for lithium-ion batteries (LIBs). We studied four C60 molecules with various functional groups, including pristine, carboxyl, ester, and piperazine C60. The comparison of these C60s elucidated a strong correlation between functional group, overall packing (crystallinity), and the anode performance in LIBs. Specifically, carboxyl C60 and neutral ester C60 showed higher charge capacities than pristine C60, whereas positively-charged piperazine C60 exhibited lower capacity. The highest charge capacity was achieved on the carboxyl C60 (861 mAh g−1 at 100th cycle), which is five times higher than that of pristine C60 (170 mAh g−1), more than double the theoretical capacity of commercial graphite (372 mAh g−1), and even higher than the theoretical capacity of graphene (744 mAh g−1). Carboxyl C60 also showed a high capacity at a fast discharge-charge rate (370 mAh g−1 at 5 C). The exceptional performance of carboxyl C60 can be attributed to multiple key factors. They include the complex formation between lithium ions and oxygen atoms on the carboxyl group, the improved lithium-binding capability of C60 cage due to electron donating from carboxylate groups, the electrostatic attraction between carboxylate groups and lithium ions, and the large lattice void space and high specific area due to carboxyl functionalization. This study indicates that, while maintaining the basic C60 electronic and geometric properties, functionalization with desired groups can achieve remarkably enhanced capacity and rate performance for lithium storage.

In this work, a novel amperometric biosensor based on carbon nanoplatelets derived from ground cherry (Physalis peruviana) husks (GCHs-CNPTs) is reported for the sensitive and selective detection of ascorbic acid (AA). The structure of the nanoplatelets, the oxygen-containing groups and edge-plane-like defective sites (EPDSs) on the GCHs-CNPTs were characterized by scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The presence of GCHs-CNPTs with a high density of EPDSs effectively enhances the electron transfer between AA and the glassy carbon electrode (GCE), and thus induces a substantial decrease in the overvoltage for AA oxidation compared with both a bare GCE and a GCE modified with carbon nanotubes (CNTs/GCE). In particular, an amperometric biosensor based on GCHs-CNPTs exhibited a wider linear range (0.01–3.57mM), higher sensitivity (208.63μAmM−1cm−2), a lower detection limit (1.09μM, S/N=3) and better resistance to fouling for AA determination compared to a CNTs/GCE. The great potential of the GCHs-CNPTs/GCE for practical and reliable AA analysis was demonstrated by the successful determination of AA in samples taken from a medical injection dose and a soft drink. Keywords: Carbon nanoplatelets, Ascorbic acid, Edge-plane-like defective sites, Electroanalysis

The relatively poor electrical conductivity of metal nitrides and the low density of their utilizable active sites have continually restricted their catalytic abilities for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) for highly efficient water splitting. Herein, for the first time, we report the design and synthesis of a novel three-dimensional (3D) hierarchically meso-macroporous and hollow tube-like architecture of Ni3N nanosheets/carbon microfibers/Ni3N nanosheets (Ni3N/CMFs/Ni3N) assembled by the dispersion of porous Ni3N nanosheets (NSs) over the inner and outer walls of hollow and porous CMFs. Benefitting from excellent electrical conductivity and a high density of utilizable active sites, Ni3N/CMFs/Ni3N revealed superior OER and HER catalytic activities compared with Ni3N supported by graphene (Gr), carbon nanotubes (CNTs) and macroporous carbons (MPCs), respectively. In O2-saturated 1.0 M KOH, the OER potential at 10 mA cm−2 [E10, 1.50 V vs. RHE] and the Tafel slope (41.54 mV dec−1) of Ni3N/CMFs/Ni3N were both lower than those of RuO2 [1.53 V vs. RHE and 43.45 mV dec−1, respectively]. Also, the HER E10 value of Ni3N/CMFs/Ni3N [−0.115 V (vs. RHE)] was only 40 mV larger than that of commercial Pt/C [−0.075 V (vs. RHE)] in N2-saturated 1.0 M KOH. For full water splitting, to achieve a current density of 20 mA cm−2 (E20) in O2-saturated 1.0 M KOH, the (−) Ni3N/CMFs/Ni3N‖Ni3N/CMFs/Ni3N (+) electrolysis cell required a cell voltage of only 1.652 V, which is only 19 mV larger than that of the state-of-the-art (−) Pt‖RuO2 (+) benchmark (1.633 V). In addition, due to the remarkable structural and chemical stabilities of Ni3N/CMFs/Ni3N, especially the unique protection of ∼2 to 3 layers of graphite carbon shells (GCSs) on the Ni3N nanoparticles (NPs) in Ni3N/CMFs/Ni3N, the Ni3N/CMFs/Ni3N-based water electrolysis cell also displayed excellent stability. The novel conceptual double surface catalysis model of Ni3N/CMFs/Ni3N, which was assembled by the dispersion of porous Ni3N nanosheets (NSs) over the inner and outer walls of hollow and porous CMFs, is an exciting new direction for the rational design and fabrication of porous nanomaterials for electrochemical energy and sensing applications.

Three oligothiophene (terthiophene, tetrathiophene and pentathiophene) derivatives are synthesized and their monolayer self-assemblies on gold (Au) are prepared via Au–S covalent bond. Our UV–Vis experimental characterization of solution reveals the dependence of the optical properties on the conjugation length of the oligothiophenes, which compares well with Time-Dependent Density Functional Theory (TDDFT) simulations of spectra of individual chromophores. Photoluminescent spectra of thin films show pronounced red shifts compared to that of solutions, suggesting strong inter-oligomer interactions. The comparative studies of cyclic voltammograms of tetrathiophene from solution, cast film and self-assembled monolayer (SAM) indicate presence of one, two, and three oxidized species in these samples, respectively, suggesting a very strong electronic coupling between tetrathiophene molecules in the SAM. Scanning tunneling microscopy (STM) imaging of SAMs of the tetrathiophene on an atomically flat Au surface exhibits formation of monolayer assemblies with molecular order, and the molecular packing appears to show an overlay of oligothiophene molecules on top of another one. In contrast, the trimer and pentamer images show only aggregated species lacking long-range order on the molecular level. Such trends in going from disordered–ordered–disordered monolayer assemblies are mainly due to a delicate balance between inter-chromophore π–π couplings, hydrophobic interaction and the propensity to form Au–S covalent bond. Such hypothesis has been validated by our computational results suggesting different interaction patterns of oligothiophenes with odd numbered and even numbered thiophene repeat units placed in a dimer configuration. Observed correlations between oligomer geometry and structural order of monolayer assembly elucidate important structure–property relationships and have implications for these molecular structures in organic optoelectronic devices and energy devices.

A comprehensive DFT study of a set of oligo(p-phenylene vinylene) molecules is performed to understand the structural and electronic changes upon functionalization. These changes are rationalized within a model considering frontier molecular orbitals of the π -conjugated system and σ -bonding orbital by which the functional group is attached to the host molecule. Two simple scalar quantum chemical descriptors are shown to correlate with optoelectronic properties of the functionalized molecule: the electronegativity and the relative electric dipole moment of the smallest π -closed shell subsystem containing the functional group and the terminal segment of the host molecule (phenyl). Both descriptors correlate linearly with the empirical Hammett σ p constant for a set of 24 functional groups. Comparison with available experimental data on UV–vis absorption and cyclic voltammetry is made. Observed structural changes reflect changes in the electronic density.

Transarterial chemoembolization (TACE) is the preferred treatment for patients with unresectable intermediate stage hepatocellular carcinoma, however currently the development of embolic agents for TACE lacks in vitro models that closely represent the sophisticated features of the organ and the vascular systems therein. In this study, we presented a new strategy using an ex vivo liver model to provide a translucent template for evaluating embolic agents of TACE. The ex vivo liver model was developed through decellularizion of rat liver organs with preserved liver-specific vasculatures and improved transmittance of the whole liver up to 23% at 550 nm. Using this model, we investigated the embolization performances of both liquid and particle-based embolic agents, including penetration depth, embolization end-points, injection pressure and spatial distribution dynamics. We found that the embolization endpoint of liquid embolic agent such as ethiodised oil was strongly dependent on the injection pressure, and the pressure quickly built up when reaching the capillary endings, which could cause embolic agent leaking and potential tissue damages. In contrast, for particle-based embolic agents such as poly- dl -lactide microparticles and CalliSpheres® beads, their embolization endpoints were mainly determined by the particle size, whereas the particle densities close to the endpoints dramatically dropped down, which with the penetration depth represented two critical factors determining the embolic distribution. Such a decellularized organ model may open a new route to visually and quantitatively characterize embolization effects of various embolotherapies.

Oxygen reduction reaction (ORR) and evolution reaction (OER) are one pair of the most important electrochemical reactions associated with energy conversion and storage technologies, such as fuel cells, metal–air batteries, and water electrolyzers. However, the sluggish ORR and OER requires a significantly large quantity of precious metals (e.g., Pt or Ir) to enhance reaction activity and durability. Highly active and robust nonprecious metal catalysts (NPMCs) are desperately required to address the cost and durability issues. Among NPMC formulations studied, carbon-based catalysts hold the greatest promise to replace these precious metals in the future due to their low-cost, extremely high surface area, excellent mechanical and electrical properties, sufficient stability under harsh environments, and high functionality. In particular, nitrogen-doped carbon nanocomposites, which were prepared from “metal-free” N–C formulations and transition metals-derived M–N–C (M=Fe or Co), have demonstrated remarkably improved catalytic activity and stability in alkaline and acidic electrolytes. In this review, based on the recent progress in the field, we aim to provide an overview for both types of carbon catalysts in terms of catalyst synthesis, structure/morphology, and catalytic activity and durability enhancement. We primarily focus on elucidation of synthesis–structure–activity correlations obtained from synthesis and extensive characterization, thereby providing guidance for rational design of advanced catalysts for the ORR. Additionally, a hybrid concept of using highly ORR active carbon nanocomposites to support Pt nanoparticles was highlighted with an aim to enhance catalytic performance and reduce required precious metal loading. Beyond the ORR, opportunities and challenges of ORR/OER bifunctional carbon composite catalysts were outlined. Perspectives on these carbon-based catalysts, future approaches, and possible pathways to address current remaining challenges are also discussed.

Reduced graphene oxide (rGO), as a newly emerged carbon material, has attracted great attention concerning its applications for electrocatalysts. Presently, there are mixed opinions regarding the advantages to using rGO as a support for preparing nonprecious metal catalysts for the oxygen reduction reaction (ORR). The primary goal of this work is to determine whether rGO would be favorable for non-precious metal catalysis of oxygen reduction or not. In the case of Fe-free catalysts, when polyaniline (PANI) was used as nitrogen/carbon precursor, the PANI-rGO catalyst is superior to the PANI-Ketjenblack (KJ) carbon black catalyst in terms of ORR activity and H 2 O 2 yield. When comparing the ORR activity of PANI-Fe-rGO to the traditional PANI-Fe-KJ, in more challenging acidic electrolyte, PANI-Fe-rGO performed no better than PANI-Fe-KJ. However, rGO does indeed enhance stability of the Fe–N–C catalyst in acidic media. In addition, in an alkaline electrolyte, ORR activity was significantly improved when using rGO in comparison to the KJ-supported Fe–N–C catalysts. Based on detailed comparisons of structures, morphologies, and reaction kinetics, the traditional KJ support with dominant microporous is able to accommodate more FeN x moieties that are crucial for the ORR in acid. Oppositely, the richness of nitrogen-doped graphene edge sites provided by rGO facilitates the ORR in the alkaline electrolyte.

The development of efficient and stable single-atom electrocatalysts with earth-abundant metals have emerged as a promising alternative to the costly Pt-based nanomaterials for oxygen reduction reaction (ORR). Herein, we synthesize a highly efficient electrocatalyst with single Fe atoms anchored by N-doped short-range ordered carbon loading on 2 D reduced graphene oxide (RGO). Unlike the highly graphitized carbon materials in previous ORR catalysts, in which the diffusion of oxygen molecules (∼3.46 A) are blocked by long carbon chains and small interlayer spacing (∼3.4 A), it is found that the Fe/N-doped nanographene possesses large interlayer spacing (>4 A) and short carbon fragments in one layer. The unique nanographene structure in nanoscale can facilitate the transport of oxygen molecules to the active sites of atomically dispersed FeN4 and FeN5. In acidic media for ORR, as-prepared Fe1-N-NG/RGO catalyst exhibited half-wave potential (E1/2) of 0.84 V versus the reversible hydrogen electrode, and the loss of E1/2 is less than 5 mV during 15,000 potential cycles.

We report solid iodine as a precursor additive for achieving purified organometallic perovskite crystals. By adding iodine, we found that the reaction can be pushed toward pure iodine phase rather than the kinetically favored chlorine phase. This approach can be applied in large crystalline perovskite solar cells and improved the average efficiency from 9.83% to 15.58%.

In recent years, the rapid development of nanoscience and nanotechnology has attracted increasing attention because of the unique optical, electrical, and electromagnetic properties of nanomaterials. The design and fabrication of hierarchical structures assembled from nanoscale building blocks are of great importance as such structures are endowed with unique properties that are distinctly different from those of the individual components. Unfortunately, the controlled synthesis of nanostructured materials with desirable properties remains a great challenge. Various approaches have been attempted to promote practical applications of nanostructured materials. Transparent and opaque Ag hydrogels and aerogels have been fabricated by the oxidation-induced self-assembly of Ag nanoshells with tunable plasmon bands in the visible spectrum. Layer-by-layer self-assembled TiO2 hierarchical nanosheets with exposed {001} facets have been reported as an effective bifunctional layer for dye-sensitized solar cells. Hollow microspheres assembled by VO2 nanowires exhibit a high capacity and excellent cyclability because of their high surface area and efficient self-expansion and self-shrinkage buffering. The successful synthesis of monodispersed Au nanotriangles leads to extended self-assembly at the air–liquid interface, which allows the development of a promising surface-enhanced Raman scattering (SERS) substrate. Uniform Ag microspheres with a nanoscale surface roughness have been synthesized as SERS substrates by the addition of poly(vinylpyrrolidone), small molecular acids, or amino acids as capping agents. The development of nanomaterials for practical applications requires synthetic methods to shift gradually from what it is to what we design. Thus, an understanding of how the chemical structures (types of functional groups, number of carbon atoms, etc.) of capping agents impact the assemblies with well-defined morphologies is of great interest. The renaissance of Raman spectroscopy depends heavily on the discovery of the SERS phenomenon related to substrates with roughened surfaces. For a long time, SERS was deemed as a noninvasive technique for chemical detection, which means the analyte will remain intact under irradiation from the light source (i.e. , laser) in Raman spectroscopy. Thus chemical enhancement (charge transfer) mechanisms were interpreted from the modified Raman spectrum of 4-aminothiophenol (4ATP) in 1994. These new peaks were considered as a robust experimental evidence of charge transfer mechanisms. p,p’-Dimercaptoazobenzene (DMAB) transformed from 4ATP by a surface catalytic coupling reaction on Ag nanoparticles was predicted theoretically and confirmed by experimental study. Since then, a number of publications have validated this hypothesis through combined theoretical We demonstrate the plasmon-driven catalytic reactions of 4-nitrothiophenol (4NTP) on a single Ag microsphere by an in situ surface-enhanced Raman spectroscopy (SERS) technique. The highly SERS-active hierarchical Ag structures served as an ideal platform to study plasmon-driven catalytic reactions. This single-particle surface-enhanced Raman spectroscopy (SPSERS) technique coupled with inbuilt apparatus allow us to study the impact of reaction atmospheres and laser power on the rate of dimerization and reduction of 4NTP. Contrary to that found in previous studies, 4NTP could be transformed into 4-aminothiophenol under H2O or H2 atmosphere. The broadening and splitting of the n(C C) band during the reaction results from the frequency shift of the n(C C) band that arises from different products. Our results suggest that the SPSERS technique is ideally suited to study plasmon-driven catalytic reactions because of the possibility to monitor the reaction under controlled atmospheres in real time.

Ho 3+ -doped strontium titanate (SrTiO 3 :Ho 3+ ) downconversion (DC) nanocrystals are synthesized by the solid state interaction of titanium dioxide, strontium nitrate, holmium oxide and sodium chloride and then used as a photoanode in dye-sensitized solar cells (DSSCs) to investigate the effect of DC nanocrystals in DSSCs. Differential thermal analysis, X-ray diffraction, scanning electronic microscope, energy dispersive spectroscopy and Brunauer–Emmet–Teller analysis confirmed the formation of cubic structured SrTiO 3 :Ho 3+ nanocrystals with diameters of 40–400 nm, pore size of ∼45 nm, sintering temperature of 950 °C. The photofluorescence and UV–Vis absorption spectra of the SrTiO 3 :Ho 3+ nanocrystals revealed strong emission intensity and visible light absorption when doped content of holmium oxide was between 1 wt% and 3 wt%. Compared with the pure SrTiO 3 photoanode, SrTiO 3 :Ho 3+ DC photoanode showed a greater photovoltaic efficiency. The photoelectric conversion efficiency ( η ) of the DSSCs with a SrTiO 3 :Ho 3+ photoanode doped with 1 wt% holmium oxide was 59% higher than that with a pure SrTiO 3 photoanode. This phenomenon could be explained by SrTiO 3 :Ho 3+ nanocrystals’ ability to absorb ultraviolet light and downconvert it to visible light, which extends spectral response range of DSSC to the ultraviolet region and increased the short-circuit current density ( Jsc ) of DSSCs.

Large-crystal perovskite films The performance of organic-inorganic hybrid perovskite planar solar cells has steadily improved. One outstanding issue is that grain boundaries and defects in polycrystalline films degrade their output. Now, two studies report the growth of millimeter-scale single crystals. Nie et al. grew continuous, pinhole-free, thin iodochloride films with a hot-casting technique and report device efficiencies of 18%. Shi et al. used antisolvent vapor-assisted crystallization to grow millimeter-scale bromide and iodide cubic crystals with charge-carrier diffusion lengths exceeding 10 mm. Science , this issue p. 522 , p. 519

A new, pH dependent and water-soluble, conjugated oligomer (amino, trimethylammonium oligophenylene vinylene, ATAOPV) was synthesized with a quaternary ammonium salt and an aromatic amine at the two ends of a π-conjugated oligomer, thus creating a strong dipole across the molecule. A unique white light LED is successfully fabricated from a stimuli responsive organic molecule whose emission properties are dominated by the pH value of the solution through controlled intermolecular charge transfer.

A series of fluorescent unnatural amino acids (UAAs) bearing stilbene and meta-phenylenevinylene (m-PPV) backbone have been synthesized by palladium-catalyzed Heck couplings., A series of fluorescent unnatural amino acids (UAAs) bearing stilbene and meta-phenylenevinylene (m-PPV) backbone have been synthesized and their optical properties were studied. These novel UAAs were derived from protected diiodo-l-tyrosine using palladium-catalyzed Heck couplings with a series of styrene analogs. Unlike the other fluorescent UAAs, whose emissions are restricted to a narrow range of wavelengths, these new amino acids display the emission peaks at broad range wavelengths (from 400–800 nm); including NIR with QY of 4% in HEPES buffer. The incorporation of both pyridine and phenol functional groups leads to distinct red, green, and blue (RGB) emission, in its basic, acidic and neutral states, respectively. More importantly, these amino acids showed reversible pH and redox response showing their promise as stimuli responsive fluorescent probes. To further demonstrate the utility of these UAAs in peptide synthesis, one of the amino acids was incorporated into a cell penetrating peptide (CPP) sequence through standard solid phase peptide synthesis. Resultant CPP was treated with two different cell lines and the internalization was monitored by confocal fluorescence microscopy.

Water-soluble cationic conjugated poly(phenylene vinylene) (PPV) and cationic fullerene were complexed with negatively charged single stranded DNA and double stranded DNA via electrostatic interactions to achieve photoinduced charge transfer with efficiencies as high as those observed from oppositely charged, cationic PPV and anionic fullerene but with distinctly different quenching mechanisms.

We demonstrate a label-free, sequence specific DNA sensor based on fluorescence resonant energy transfer (FRET) occurring between a cationic conjugated polyelectrolyte and a small intercalating dye, malachite green chloride. The sensor combines (1) conjugated polymer chain conformation changes induced by the binding with DNA, with the conjugated polymer wrapping/twisting around the DNA helical duplex and experiencing a 3-fold increase in its photoluminescence quantum yield and (2) FRET from the conjugated polymer to the intercalated DNA. Owing to its small size, the dye intercalates at maximal, one-to-one dye-to-base pair load, making the intercalated DNA a molecular photonic wire with dyes excitonically coupled and chiroptically active. Any sequence mismatch between probe and target DNA degrades the intercalated DNA photonic wire by decreasing its brightness, excitonic coupling, and chiroptical properties, and this provides a signal transduction method for the DNA sensor. Coupling of intercalated DNA wit...

In this contribution, six conjugated polymers consisting of benzo[1,2-b:4,5-b′]dithiophene–bithiophene (BDT-BT) and benzo[1,2-b:4,5-b′]dithiophene–benzothiadiazle (BDT-BTD) as building blocks in the main chain were synthesized by coupling polymerization and utilized for photovoltaic applications. By directly attaching three kinds of alkylthienyl side chains to the conjugated main chain, the resulted two-dimensional configuration revealed a broader absorption range due to the ground state electron transition of their corresponding alkylthienyl units and polymer backbone. Temperature-dependent absorbance, emission spectra, and thermal annealing further verify that the shoulder band(s) were originated from the aggregated (crystalline) species of polymers. The photovoltaic properties of the donor–acceptor polymers revealed well-defined side chain geometries, physical, and electronic structures and showed the highest power conversion efficiency of 4.25% among polymer solar cells based on two-dimensional (2-D) ...

Flexible nonvolatile memory devices were fabricated from benzodithiophene-based donor–donor and donor–acceptor 2D conjugated polymers with thermally/non-thermally recoverable memory behaviors.

White organic light-emitting diode (WOLED) technology has attracted considerable attention because of its potential use as a next-generation solid-state lighting source. However, most of the reported WOLEDs that employ the combination of multi-emissive materials to generate white emission may suffer from color instability, high material cost, and a complex fabrication procedure which can be diminished by the single-emitter-based WOLED. Herein, a color-tunable material, tris(4-(phenylethynyl)phenyl)amine (TPEPA), is reported, whose photoluminescence (PL) spectrum is altered by adjusting the thermal annealing temperature nearly encompassing the entire visible spectra. Density functional theory calculations and transmission electron microscopy results offer mechanistic understanding of the PL redshift resulting from thermally activated rotation of benzene rings and rotation of 4-(phenylethynyl) phenyl)amine connected to the central nitrogen atom that lead to formation of ordered molecular packing which improves the π-π stacking degree and increases electronic coupling. Further, by precisely controlling the annealing time and temperature, a white-light OLED is fabricated with the maximum external quantum efficiency of 3.4% with TPEPA as the only emissive molecule. As far as it is known, thus far, this is the best performance achieved for single small organic molecule based WOLED devices.

Nitrogen-doped graphene/graphene-tube nanocomposites are prepared by a hightemperature approach using a newly designed cage-containing metal-organic framework (MOF) to template nitrogen/carbon (dicyandiamide) and iron precursors. The resulting N-Fe-MOF catalysts universally exhibit high oxygen-reduction activity in acidic, alkaline, and non-aqueous electrolytes and superior cathode performance in Li-O2 batteries.

The present study reported here synthesis of three novel two-dimensional (2D) polythiophene derivatives with conjugated terthiophene–vinylene side chain—poly{3-(5″-hexyl-2,2′:5′,2″-terthiophenyl-5-vinyl)thiophene-alt-thiophene} (P1), poly{3-(5,5″-dihexyl-2,2′:5′,2″-terthiophenyl-3′-vinyl)thiophene-alt-thiophene} (P2), and poly{3-(4,4″-dihexyl-2,2:5′,2″-terthiophene-3′-vinyl)thiophene-alt-thiophene} (P3)—that were synthesized via stille coupling reaction. The terthiophene side chain with different conformations conjugated to the polythiophene main chain via vinyl linkage provided the ability to control the molecular organization, hence affecting the optoelectronic and electrochemical properties of 2D polymers. TD-DFT calculation with the B3LYP/6-31+g(d) function on electronic structures of the monomers was consistent with the experimental results. It suggested that the energetic states of HOMO and LUMO were highly dependent on the side-chain architectures. These polythiophene thin films fabricated by spin-...

Mg can store up to ∼7 wt.% hydrogen and has great potential as light-weight and low cost hydrogen storage materials. However hydrogen sorption in Mg typically requires ∼573 K, whereas the target operation temperature of fuel cells in automobiles is ∼373 K or less. Here we demonstrate that stress-induced orthorhombic Mg hydride (O-MgH2) is thermodynamically destabilized at ∼ 373 K or lower. Such drastic destabilization arises from large tensile stress in single layer O-MgH2 bonded to rigid substrate, or compressive stress due to large volume change incompatibility in Mg/Nb multilayers. Hydrogen (H2) desorption occurred at room temperature in O-MgH2 10 nm/O-NbH 10 nm multilayers. Ab initio calculations show that constraints imposed by the thin-film environment can significantly reduce hydride formation enthalpy, verifying the experimental observations. These studies provide key insight on the mechanisms that can significantly destabilize Mg hydride and other type of metal hydrides.

Cu2O nanocrystals with different morphologies are synthesized via a reductive solution route by controlling the reaction time and using different capping agents. Introducing poly(ethylene glycol) (PEG) leads to nearly monodispersed Cu2O nanocubes with 40 nm size and dominant {100} crystal planes. With prolonged reaction time, the nanocubes are truncated and transformed into sphere-like nanocrystals with more {111} planes exposed. In the presence of poly(vinyl pyrrolidone) (PVP), porous Cu2O nanocrystals with both {100} and {111} planes present are produced. The structure-dependent electrocatalytic activity of Cu2O nanocrystals toward oxygen reduction reaction (ORR) has been studied in alkaline electrolyte. The electrocatalytic activity measured on Cu2O {100} is higher than that on Cu2O {111}. In addition, the Cu2O nanocubes with dominant {100} crystal planes show the highest four-electron selectivity (n = 3.7) and lowest peroxide yield (15%) during the ORR. Kinetics analysis indicates that the ORR mechani...

Conjugated polyelectrolytes (CPEs) are promising materials for generating optoelectronics devices under environmentally friendly processing conditions, but challenges remain to develop methods to define lateral features for improved junction interfaces and direct optoelectronic pathways. We describe here the potential to use a bottom-up approach that employs self-assembly in lipid membranes to form structures to template the selective adsorption of CPEs. Phase separation of gel phase anionic lipids and fluid phase phosphocholine lipids allowed the formation of negatively charged domain assemblies that selectively adsorb a cationic conjugated polyelectrolyte (P2). Spectroscopic studies found the adsorption of P2 to negatively charged membranes resulted in minimal structural change of the solution phase polymer but yielded an enhancement in fluorescence intensity (~50%) due to loss of quenching pathways. Fluorescence microscopy, dynamic light scattering, and AFM imaging were used to characterize the polymer-membrane interaction and the polymer-bound domain structures of the biphasic membranes. In addition to randomly formed circular gel phase domains, we also show that predefined features, such as straight lines, can be directed to form upon etched patterns on the substrate, thus providing potential routes toward the self-organization of optoelectronic architectures.

Phenylene vinylene trimer (OPV) and PNIPAM conjugate with stimuli-responsive optical properties has been synthesized through the formation of amide linkage between PNIPAM and carboxylic-acid-terminated OPV. This material exhibits thermoresponsive optical properties as temperature exceeds the lower critical solution temperature (LCST), which is 32 °C for PNIPAM and the conjugate. This PNIPAM-trimer conjugate is fully characterized by using NMR, FT-IR, temperature-dependent UV–vis, and fluorescence spectroscopy. We have found that the polymer conjugate solution turns opaque as temperature exceeds lower critical solution temperature and a five-fold increase in fluorescence intensity as temperature increases from 20 to 70 °C. Such distinct increase in fluorescence intensity is likely due to the rigidchromism, that is, the change in optical properties due to confinement of the chromophores resulting from restriction of polymer conformational structures. The PNIPAM-trimer conjugate also shows a decrease in deca...

Two water soluble conjugated polymers, poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) and ammonium ion stabilized poly(phenylene vinylene) (P2), are found to be able to reduce noble metal ions to zero-valent metals via a direct chemical deposition technique. Au nanoparticle clusters can be obtained through reduction of Au 3+ ions by PEDOT:PSS and the electronic coupling between them can be controlled by HAuCl 4 concentration. Core/shell Ag/polymer nanostructures are prepared from reduction of Ag + ions by P2, which have a ppb detection limit for 4-MBA using surface-enhanced Raman spectroscopy (SERS). This conjugated polymer mediated synthesis of metal nanoparticles may open a new avenue for fabricating nanomaterials and nanocomposites with tunable optical properties that are dominated by their structure and electronic coupling between nanoparticles.