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Single-crystalline SnO 2 nanorods with tunable length are synthesized via a facile and surfactant-free solvothermal route based on an aqueous–organic solvent system. The length of the nanorods can be facilely controlled by adjusting the solvent ratio. Particularly, the average length increases from 14.6 to 98.0 nm when the volume ratio of cyclohexane to water is varied from 20:30 to 49:1. The morphological evolution of the SnO 2 nanorods is systematically investigated, and a growth mechanism involving three stages of nucleation, rearrangement and oriented growth is proposed, based on the free migration of the nanoparticles at the two immiscible interfaces thereby offering special path for the self-assembly. The synthesized SnO 2 nanorods are used as photoanodes for dye-sensitized solar cells (DSSCs) and the photovoltaic performance is studied as a function of the morphology. UV–vis absorption spectra show the dye-loading capabilities of the DSSCs are gradually weaken with the length increase of the SnO 2 nanorods. Electrochemical impedance spectroscopy analysis indicates that the charge transfer resistances at the SnO 2 /dye/electrolyte interfaces decrease and the electron lifetimes increase along with the increase of nanorod-length. As a consequence, DSSCs fabricated from medium-sized nanorods achieve the best power conversion efficiency of 3.50% due to the equilibrium between fast electron transport and large specific surface area. [ABSTRACT FROM AUTHOR]

The presence of heterogeneous interfacial defects limits the efficiency and long-term stability of the perovskite solar cells (PSCs). Rational passivation of interfacial defects and reduction of nonradiative recombination at the perovskite active layer are effective ways to achieve efficient PSCs. Here, a heterointerface engineering strategy is presented by employing a multifunctional molecule of reduced l -glutathione (GSH). The introduction of GSH improves the crystallization of SnO 2 , resulting in a continuous and conformal coverage of SnO 2 on the FTO surface. And the GSH buffer layer improves the affinity between SnO 2 and perovskite, resulting in the formation of large grains of perovskite. In addition, GSH bridges the perovskite to SnO 2 through multi-dentate ligands (-COOH, –NH 2 , –CONH–, –HS), which passivates the multiple defects at the heterogeneous interfaces while accelerates the electron transport. As a result, the PCE of the GSH-SnO 2 ETL based PSC significantly increases to 21.66% with no noticeable hysteresis. Meanwhile, compared with the control PSC, the unencapsulated GSH-SnO 2 based PSC exhibits better environmental stability, which maintains more than 80% of its initial PCE after 600 h of placement in atmospheric environment. GSH bridges the perovskite to SnO 2 through multi-dentate ligands, which passivates the multiple defects at the heterogeneous interfaces while accelerates the electron transport. [Display omitted] • GSH-SnO 2 has a contiguous and conformal coverage on the FTO substrate. • Multidentate ligands dually passivate various defects at the SnO 2 /perovskite heterogeneous interface. • An electron transport bridge is constructed between SnO 2 and perovskite layer. • The GSH-SnO 2 based PSCs achieve an enhanced PCE of 21.66%. [ABSTRACT FROM AUTHOR]

Three-dimensional titania network was in-situ constructed on Ti foil via sequential acid and hydrogen peroxide treatments. The titania network was pure anatase phase and homogeneously covered on the titanium grain surface, which largely enhanced the roughness of the Ti foil. The as-received Ti foil and the treated one were used as the flexible substrates of DSSCs, and energy conversion efficiencies of 3.74% and 4.98% were obtained, respectively. Such remarkable increment can be ascribed to the good electrical contact between the nanocrystalline TiO 2 and the Ti foil, the improved electron percolation pathways and recombination inhibition of electrons in Ti substrate with triiodide ions in electrolyte. Flexible DSSCs based on the treated Ti foil showed relatively good mechanical stability, which exhibited 97.3% retention of the initial efficieny after twenty consecutive bending. [ABSTRACT FROM AUTHOR]

Hierarchical anatase TiO 2 submicrospheres were synthesized by direct hydrothermal method at 120 °C using Ti(SO 4 ) 2 and (NH 4 ) 2 SO 4 mixed solution as precursor. The calcined spheres in particle size of 150–200 nm, which consisted of closely connected nanocrystals in a crystallite size of about 24.2 nm and had a relatively high specific surface area of 43.2 m 2 g −1 compared to microspheres. In presence of TiO 2 submicrospheres as the scattering layer on top of semitransparent layer, the power conversion efficiency of dye-sensitized solar cells (DSSCs) was increased to as high as of 9.07% from 7.24%. This remarkable improvement compared to commercial scattering particles (efficiency of 8.33%) is mainly attributed to their higher surface area for increasing the loading of dye molecule as well as a lower resistance under 1 sun irradiation. The relationship between the conversion efficiency of DSSCs with interfacial resistance under 0.1 to 1.0 sun illumination was further investigated, the decrease of the light power density led to the increase of interfacial resistance. Moreover, even under 0.1 sun irradiation, DSSC still had an efficiency of 7.18% but a slightly lower V oc of 0.597 V. [ABSTRACT FROM AUTHOR]

Hierarchical TiO 2 hollow microspheres were synthesized by a 2-step process consisting of thermal hydrolysis and subsequent solvothermal reaction. Quasi-monodispersed solid TiO 2 microspheres aggregated by amorphous particles were firstly obtained by the controlled thermal hydrolysis of titanium sulfate, and then the solid structures transformed to hollow ones and crystallized during the subsequent solvothermal treatment. SEM and TEM images of the samples revealed that the morphological evolution was in perfect accordance with the inside-out Ostwald ripening mechanism. The rich porosity and unique hierarchical hollow structure endow the TiO 2 microspheres with a large specific surface area of 108.0 m 2 g −1 . As an effective anode material for dye-sensitized solar cells, TiO 2 hollow microspheres showed good capability of dye adsorption and strong light scattering, leading to a comparable energy conversion efficiency to the commercial 18NR-T transparent titania. Finally, a high efficiency of 7.84% was achieved for the bi-layer DSSC by coating the hollow microspheres on top of the 18NR-T titania as the light scattering layer. [ABSTRACT FROM AUTHOR]

In this article, a novel and facile strategy to load low-cost and earth-abundant oxygen evolution catalyst NiFeO x by spin-coating on Ti-doped α-Fe 2 O 3 films was reported. The NiFeO x modified hematite photoanode was prepared by a two-step process, which consisted of a hydrothermal method and a subsequent NiFeO x loading step. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and electrochemical impedance spectroscopy (EIS) were used to characterize the resulting photoanode. The highest photocurrent increment and lowest onset potential were observed with 30 mM NiFe precursor treatment. Increasing the loading content in a range from 10 to 90 mM, the photocurrent density increases from 0.998 for the pristine α-Fe 2 O 3 to 1.126 mA/cm 2 at 1.23 V vs RHE (i.e., 12.7% increment) with 30 mM NiFe precursor treatment. Concomitant with this improvement was a cathode shift in the onset potential by nearly 55 mV and higher incident-photon-to-current efficiencies. Hematite photoanodes after NiFeO x deposition showed better performance than pristine samples, because of a lower overpotential for water oxidation resulted from NiFeO x modifying. [ABSTRACT FROM AUTHOR]

Zinc-cobalt layered double hydroxide (LDH) was electrodeposited on Ti-doped hematite photoanodes for the first time, and a significant enhanced performance for photoelectrochemical water splitting was demonstrated over the composite photoanodes. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and electrochemical impedance spectroscopy (EIS) were characterized with the resulted photoanodes. With the electrodepositing treatment, the photocurrent density increased from 1.27 mA/cm 2 for pristine hematite to 1.73 mA/cm 2 for modified materials at 1.23 V vs. RHE (i.e. 36% improvement). The photocurrent improvement is mainly attributed to a suppression of electron–hole recombination and reduced overpotential for water oxidation at the hematite-electrolyte interface due to the formation of Zn-Co LDH layer on hematite. [ABSTRACT FROM AUTHOR]

TiO 2 nanocrystals derived from hydrothermal method were widely used as the photoanodes of dye-sensitized solar cells (DSSCs). Developing some alternative routes combining low-cost with high performance is eagerly expected. Well connected anatase TiO 2 nanocrystals were synthesized by one-step thermal decomposition of the double salt (NH 4 ) 2 TiO(SO 4 ) 2 (ammonium titanyl sulfate, ATS) at 700 °C for 2 h, and the fine tuning on aggregate sizes was achieved by adjusting the heating rate. The TiO 2 nanocrystals inside the aggregates were densely packed where each nanocrystal contacted well to neighbouring grains. The connected structure between the crystallites decreases the negative effects of electron grain boundary crossing and reduces recombination within the aggregate when used as photoelectrodes of dye-sensitized solar cells. Moreover, TiO 2 aggregates from ATS calcined at a faster heating rate (5 °C/min) had a wider pore size distribution and exhibited a higher light scattering abilities, while the ones from those calcined at a slower heating rate (3 °C/min) had a narrow pore size distribution but possessed a higher specific surface area (72.8 m 2 g −1 ) for adsorbing more dye. The DSSC based on two kind of TiO 2 nanoparticles as the photoelectrode all exhibited an excellent short-circuit current density (15.21 mA cm −2 and 15.94 mA cm −2 ) and a highly efficient power conversion efficiency (7.78% and 8.16%). The improvements of power conversion efficiency for two kinds of TiO 2 nanoparticles compared to commercial Aerosil process P25 nanoparticles are mainly attributed to a higher light scattering ability and superior dye adsorption property, respectively. The electrochemical impedance spectroscopy (EIS) analysis indicated the DSSCs with TiO 2 nanocrystals derived from solid state reaction had a lower charge transfer resistance than all P25 photoanodes at TiO 2 /dye/electrolyte interface due to the well connected structure provided multiple contacts to neighboring grains. [ABSTRACT FROM AUTHOR]

Highlights: [•] The anatase TiO2 sol with a crystallite size of 3.0nm was prepared. [•] Both TiO2 sol and titanium (IV) bis (ammonium lactato) dihydroxide were successfully used towards size-tunable anatase TiO2 nanocrystals. [•] The DSSC with an efficiency of 9.3% was archived by combining of TiO2 nanocrystals and sol treatment. [•] Improved interfacial contact was responsible to the performance enhancement of DSSCs. [ABSTRACT FROM AUTHOR]

We present a compelling strategy for fabricating a hierarchical OER electrode, successively consisting of the nickel foam (NF) conductive substrate, carbon-incorporated cobalt oxide nanorod arrays, and nickel-iron hydroxide nanosheets (NF/CoO–C/NiFe–OH). Cobalt-based metal-organic framework (Co-MOF) derived porous CoO–C matrix increases electrical conductivity, facilitates charge transfer, and provides more surface sites for the NiFe–OH deposition. Furthermore, the CoO–C and NiFe–OH heterostructure alters the electronic states of active components, consequently achieving a synergistic role that promotes the OER process. The resulting NF/CoO–C/NiFe–OH exhibits prominent OER activity, with the overpotentials of 281, 347, and 466 mV at 50, 100, and 200 mA cm−2 of current densities, respectively. In the meantime, it also possesses a lower Tafel slope of 39 mV dec−1, larger electrochemical surface area, faster turnover frequencies, and lesser charge transfer resistances. Additionally, the electrode reveals superior stability without significant morphological changes and element valence states. The OER mechanism and electrochemical performance of hierarchical heterostructure regulated by nickel-iron oxyhydroxides on carbon-incorporated cobalt oxide nanorod arrays on the NF substrate (NF/CoO–C/NiFe–OH). [Display omitted] • The in-situ strategy of CoO–C/NiFe–OH hierarchical heterostructure is used. • The CoO–C matrix improves surface structure and electronic states of NiFe–OH. • The NF/CoO–C/NiFe–OH electrode has superior OER performance and durability. • The promoting mechanism of the CoO–C layer on the OER process is proposed. [ABSTRACT FROM AUTHOR]

One-dimensional nanorod arrays show great potential as electron transport layers of perovskite solar cells due to their unique characteristic of oriented electron transport. Herein, anatase phase TiO 2 nanorod arrays are successfully grown on FTO conductive glass by a facile hydrothermal method using tetrabutyl titanate as precursor. By regulating the concentration of tetrabutyl titanate, TiO 2 nanorods with the length of 50, 200, 300 and 1000 nm are synthesized. XRD and Raman spectra show that the nanorods are pure anatase phase, while SEM and TEM images reveal that they are polycrystalline structure. The anatase TiO 2 nanorod array films have homogeneous surface morphologies, which are beneficial to deposit compact and pinhole-free perovskite films. The light absorption, photoluminescence quenching and trap densities of the films are systematically investigated. Consequently, the perovskite solar cells based on 50 nm anatase TiO 2 nanorod arrays show the best photoelectric conversion efficiency of 15.3%, and those based on 200, 300, 1000 nm nanorod arrays achieve the photoelectric conversion efficiencies of 14.5%, 13.8% and 12.1%, respectively. Perovskite solar cells based on anatase TiO 2 nanorod arrays exhibit a high power conversion efficiency of 15.3%. Image 1 • New approach for the synthesis of anatase phase TiO 2 nanorod arrays. • Anatase TiO 2 nanorod arrays with tunable length ranged from 50 to 1000 nm. • PSCs based on anatase TiO 2 nanorod arrays yield a high efficiency of 15.3%. [ABSTRACT FROM AUTHOR]

Mesoporous SnO 2 microspheres are a class of promising electron transport materials for mesoscopic perovskite solar cells, but a smooth and dense film as requested by electron transport layer is difficult to realize using the microspheres. Here, a series of monodispersed SnO 2 microspheres with high specific surface area and good crystallinity are synthesized via a surfactant-free solvothermal method. These SnO 2 microspheres showing small diameters of about 75, 110 and 200 nm with narrow size distribution are achieved by precisely controlling the crystal growth process. They are suitable for constructing the electron transport layers whose thickness is only about hundreds nanometers. Besides, as the microspheres easily slip off from the substrate during the conventional spin coating process, the spray coating method is exploited to prepare high quality electron transport layers. As a result, a power conversion efficiency of 16.85% is yielded by using the 75 nm sized SnO 2 microspheres as the electron transport layers. This high power conversion efficiency is attributed to the fast electron transport and inhibited charge recombination. To further improve the charge transfer between the electron transport layer and perovskite layer, graphene quantum dots are added into the SnO 2 microspheres, and a best efficiency of 17.08% is obtained. Image 1 • SnO 2 microspheres with small diameters of 75, 110 and 200 nm are synthesized. • High quality SnO 2 microsphere electron transport layers are prepared by spray coating. • A high efficiency of 17.08% is obtained for the mesoscopic perovskite solar cells. [ABSTRACT FROM AUTHOR]

We report an in-situ construction strategy of Z-type In 2 O 3 @InP hydrogen evolution reaction (HER) electrocatalyst with well-defined core-shell structure on nickel foam (In 2 O 3 @InP/NF) via sequential hydrothermal, annealing, and phosphating steps. The phosphating time dramatically affects the morphology, crystal phase, elemental composition, and optical properties of In 2 O 3 @InP. The resulting electrode obtained with 2 h of phosphating time has smaller overpotentials and Tafel slope, larger TOF and ECSA, and lower charge transfer resistance compared to In 2 O 3 /NF. The better activity reveals the promoted roles of InP that can provide more active sites, facilitate charge transfer, and accelerate the adsorption of H* species. The photo-assisted electrocatalytic activity for HER is significantly enhanced attributed to the strong light absorption capacity of InP, superior energy level configuration of In 2 O 3 and InP, and excellent transient light response of In 2 O 3 @InP. Furthermore, the electrode has favorable stability and durability, and the morphology and surface chemical state have no essential changes after the photo-assisted HER stability test. The promoting mechanism of photo-assisted HER for the Z-type In 2 O 3 @InP/NF electrode and HER activities in the dark and under AM 1.5 G light illumination. [Display omitted] • The in-situ construction strategy of In 2 O 3 @InP core-shell heterostructure is used. • The InP layer enhances surface chemical states and optical properties of In 2 O 3. • In 2 O 3 @InP has superior photo-assisted activity, stability, and durability for HER. • The promoting mechanism of photo-assisted HER for Z-type In 2 O 3 @InP is determined. [ABSTRACT FROM AUTHOR]

Efficient and earth-abundant electrocatalysts for water oxidation are essential for renewable and sustainable energy conversion technologies. And Ni(Fe)O x H y especially attractive as a state-of-the-art best candidate catalyst for efficient electrochemical oxygen evolution reaction (OER). In previous research, Cr has been reported could benefit the Ni(Fe)O x H y catalysts with conflicting mechanism. Here, a series of ternary (Ni, Fe and Cr) amorphous metal oxide catalysts for OER are synthesized via a simple thermal decomposition method. We show that Ni 0.6 Fe 0.3 Cr 0.1 O x has a turnover frequency of 0.046 ± 0.004 s −1  at 300 mV overpotential which is ∼31% more active than an analogous Ni 0.6 Fe 0.4 O x film, 0.035 ± 0.007 s −1 , in 0.1 M KOH media. Using electrochemical voltammetry and AC impedance analysis, we demonstrate that Cr increases the number of electrochemically available active sites, as a pore forming agent, but does not affect the intrinsic per metal atom activity. We find that the Cr begins to leach immediately upon electrochemical testing, and the Cr is almost completely depleted after a 24 h stability test. Importantly, along with the decreased content of Cr, the catalyst activity is further promoted. Although the Cr itself may not be responsible for the improvement, its dissolution results in an ideal type of pore and/or active sites. We further optimize the deposition of high-surface-area and high-mass-loading Ni 0.6 Fe 0.3 Cr 0.1 O x on carbon-cloth electrodes and demonstrate an overpotential as low as 251 mV at 10 mA cm −2 in 1 M KOH. [ABSTRACT FROM AUTHOR]

The photovoltaic performance of perovskite solar cells is extremely dependent on the crystallization and morphology of the perovskite film, which are affected by the deposition method. Here, we demonstrate a simple approach to form a microporous PbI 2 film, with subsequent conversion to a compact, highly crystalline perovskite film. The PbI 2 and corresponding perovskite films were further probed by two-dimensional X-ray diffraction. The resultant perovskite exhibited improved photovoltaic performance under ambient conditions with about 50% humidity. The PbI 2 microporous structure was formed by exchanging residual DMSO with DMF vapor in the PbI 2 film, which facilitated contact with the methylammonium iodide (MAI) solution. The process resulted in the formation of compact, smooth, pinhole-free perovskite films having no residual PbI 2 . Solar cells fabricated using this methodology exhibited power conversion efficiencies over 16% with negligible photocurrent hysteresis. [ABSTRACT FROM AUTHOR]

We report an in-situ construction method for the NiFe-based oxyhydroxide OER electrocatalyst supported on the nickel foam (NF) substrate with the polyaniline (PANI) interlayer by sequential electrochemical deposition steps (NF/PANI/NiFe–OH). The ultra-thin nanosheet for the nickel-iron (oxy)hydroxides tightly grown on the porous PANI exhibits the enhanced electrochemical characteristics associated with the promotion roles of the PANI layer, which increases the number of active sites, facilitates the charge transfer, and accelerates water transport across the interfaces of the electrode. The as-prepared NF/PANI/NiFe–OH has reliable lower overpotentials of 260, 340, and 490 mV without iR -correction at 50, 100, and 200 mA cm−2 of high current densities, respectively. The smaller Tafel slope, larger ECSA, and TOF values of the electrode reveal its high intrinsic activity. Moreover, the electrode shows good stability and durability without the damage of morphology, change of surface chemical state, and substantial loss of active components at high current density. The OER mechanism and stability of electrodeposited polyaniline/nickel-iron oxyhydroxide stabilized on nickel foam (NF/PANI/NiFe-OH). [Display omitted] • The in-situ construction method for electrodeposited PANI/NiFe–OH is used. • The PANI interlayer improves the surface structure and chemical state of NiFe–OH. • The PANI/NiFe–OH electrode has superior OER activity compared to NiFe–OH. • The promoting mechanism of PANI on electrochemical OER performance is determined. [ABSTRACT FROM AUTHOR]

Hindered by price and scarcity, the exploitation of supported Pt-based electrocatalysts with Pt single atoms or Pt nanoclusters is an alternative way to decrease the dosage of Pt and improve the electrocatalytic performance for hydrogen evolution reaction (HER) of water splitting. The anodization technology is used to modify the surface of nickel foam (NF) to form the porous NiF 2 network structure. Then Pt nanodots interfaced with Ni(OH) 2 (Pt/Ni(OH) 2) hybrid on the anodized NF has been in-situ synthesized by a simple hydrothermal decomposition method. Results show that Pt nanodots on the substrate have good dispersion with the average size of 3 nm, and the Pt loading is only 0.229 mg cm−2. The prepared electrode exhibits the low overpotentials of 25.9 mV and 211 mV at the current densities of 10 and 100 mA cm−2, respectively, a small Tafel slope of 37.6 mV dec−1, and the excellent durability for HER. The porous network nanostructure of Pt/Ni(OH) 2 hybrid, the large electrochemical surface area, the fast facilitated electron transport capability, and the firm adhesion of Pt nanodots with the anodized NF substrate contribute to the remarkable performance towards HER. Image 1 • A simple hydrothermal decomposition method was used to synthesize Pt nanodots. • The anodized NF contributes to the porous network nanostructure of Pt/Ni(OH) 2 hybrid. • The modification of the NF substrate enhances the HER performance of the electrodes. • The mechanisms of the efficient HER for the Pt/Ni(OH) 2 /NF-A electrode are explained. [ABSTRACT FROM AUTHOR]

A facile approach that combines the chemical etching with sulfidation of the sacrificial templates of the Fe-based MOFs is developed to prepare FeS 2 @ Porous Octahedral Carbon (FeS 2 @POC). The porous carbon shell can improve the conductivity of active materials, bring a high reversible capacity. Moreover, the void space between carbon and FeS 2 can accommodate the volume changes during cycling and the existence of carbon can prevent the aggregation of pulverized FeS 2 particles during Li ions insertion/extraction process, which are favorable to gain superior cycling stability. When used as an anode for lithium-ion batteries, the FeS 2 @POC shows superior electrochemical performance with a high specific capacity, excellent rate performance (381 mAh g−1 at 5000 mA g−1) and good cyclability (1074 mAh g−1 at 100 mA g−1 after 100 cycles, about 99% capacity retention). The results demonstrate that this product may be considered as a promising anode material for advanced lithium-ion batteries. [ABSTRACT FROM AUTHOR]

• Well-crystallized perovskite films were prepared at near-room temperature of 50 °C. • Effect of Cs+ cations on diffusion of organic cations in intermediate phases was described. • The PSCs with corresponding perovskite layers possessed a highest PCE of 17.9%. Perovskite crystallizations under different temperature phases have tremendously effects on the performance of perovskite solar cells. Here, we report an effective near-room-temperature fabrication technique to prepare high quality organolead halide perovskite films. By doping a certain amount of cesium cations into precursor solution, smooth and well-crystallized perovskite films with no other impurity phase can be obtained at an annealing temperature of 50 °C. This phenomenon can be interpreted as relatively low energy required for the diffusion of cesium cations into intermediate phase framework, promoting the removal of DMSO and subsequent diffusion of organic cations. Corresponding PSCs has been prepared based on this technique, and the highest PCE of 17.9% has been obtained with annealing temperature of only 50 °C. This work exhibits a well balance between reducing of annealing temperature and increase of device performance and is expected to broaden the range of choices for substrate materials. [ABSTRACT FROM AUTHOR]

The development of highly efficient latent fingerprints technology (LFPs) on different background remains extremely vital for forensic and criminal investigations. In this work, a pure organic molecular sensor (DPTPA1) was designed to image LFP with strong signal-to-noise ratio by optimizing the imaging technology. DPTPA1 exhibits aggregation-induced emission (AIE) properties in both aqueous solution and solid state. Two pyridine moieties and one aldehyde moiety were introduced as the end-capped units. DPTPA1 exhibits the typical solvatochromic effect whose maximum emission wavelengths red-shift from 410 nm to 540 nm with the increasing polarity of solvents. The obvious emission of DPTPA1 in the aqueous solution is observed around 500 nm (φ = 9.6%). Both cyanoacrylate glue fuming (CGF) and powder dusting (PD) methods were used to obtain the fluorescent images of LFP on glass, tinfoil, steel and plastic substrates. Among them, the CGF method can image the clear second level details of LFP on the glass and tinfoil. The PD method using DPTPA1-loaded silica gel material can obtain the high quality LFP images on the curved surface of all four substrates. This work provides a strategy for lowing the cost in the broad fields of LFPs imaging. An AIE-active dipyridnyltriphenylamine derivative (DPTPA) shows good fluorescent properties in aqueous solution, powder and silica gel complex, which can perform optimizing latent fingerprints imaging by using cyanoacrylate glue fuming and powder dusting methods. [Display omitted] • A dipyridnyltriphenylamie-based fluorescent agent (DPTPA) were synthesized. • DPTPA exhibits obvious aggregation-induced emission. • The aqueous solution of DPTPA outputs the fluorescence around 500 nm (φ = 9.6 %). • A low cost imaging agent and silica gel-based formula for LFPs imaging were provided. • LFPs imaging is processed by both cyanoacrylate glue fuming and powder dusting methods. [ABSTRACT FROM AUTHOR]

Abstract SnO x is considered as a promising anode candidate for lithium-ion batteries, but suffers from the low electrical conductivity and severe volume expansion during cycling. To solve these issues, we develop a simple and facile process of incipient wetness impregnation followed by pyrolysis gel molecules to prepare SnO x /mesoporous carbon nanofiber arrays, SnO x /graphene, SnO x /carbon nanotubes and SnO x /three-dimensionally ordered macroporous carbon materials. Notably, SnO x nanoparticles about 5 nm are prepared by a nonaqueous sol-gel method. We also explore the effect of different morphologies and pore structures of four carbon substrates on the electrochemical performance of the composites. Benefiting from the small size of SnO x nanoparticles and the synergistic effect between SnO x and the different carbon matrix materials, SnO x -Carbon electrode materials display excellent rate capability and cycle stability. SnO x /mesoporous carbon nanofiber arrays exhibits the best rate (522 mA h g−1 at 2000 mA g−1) and cycling performances (1327 mA h g−1 after 200 cycles at 100 mA g−1). The superior electrochemical performance, facile synthesized method and low cost of the Sn-based materials exhibit promising application for SnO x /mesoporous carbon nanofiber arrays as anode materials for next-generation lithium-ion batteries. Furthermore, the ex situ X-ray photoelectron spectroscopy studies on this electrode material under different states suggest that the Sn and Li 2 O could reversibly react to form SnO x during the charging process. [ABSTRACT FROM AUTHOR]

In this work, carboxyl groups were introduced on the organic ligands of ZIF-67 through post-synthetic modification (-CH 3 →-CH 2 Br→-CHO→-COOH). A thin layer of Ag nanoparticles (3 nm in diameter) coating was deposited on external surface of ZIF-67 crystals through the reaction between the aldehyde groups in the ligands and silver ammonia solution. The carboxyl groups can participate in the lithium storage while the Ag nanoparticles coating help in increasing the conductivity. Electrochemical properties of the modified ZIF-67 electrodes are examined by cyclic voltammetry and galvanostatic charge/discharge tests. Benefiting from the outstanding conductivity of Ag nanoparticles and the synergistic effect between Ag nanoparticles and the modified ZIF-67, the composite exhibits enhanced electrochemical performance compared to its ZIF-67 counterpart. Nearly an invariable capacity of 800 mA h g −1 is maintained up to 100 cycles at 0.28 C (1C = 137 mA g −1 ) with a Coulombic efficiency of 99%. Furthermore, the ex situ X-ray diffraction and X-ray photoelectron spectroscopy studies on the electrode material under different states suggest that the Co ions remain in the Co 2+ state during the charging/discharging process and the usual conversion reaction mechanism for lithium storage might not be suitable for the modified ZIF-67 electrode material. [ABSTRACT FROM AUTHOR]

Ellipsoidal TiO 2 mesocrystals (MCs) with varying particle sizes depending on the amount of titanium precursor are synthesized by solvothermal method using acetic acid and tetrabutyl titanate. The large one (MC-1) is predominant 700 nm in length and 400 nm in width, while the small one (MC-2) is 250 nm in length and 100 nm in width. SEM and TEM images reveal that the mesocrystals exhibit single-crystalline-like structures, which are constructed by the orderly aggregating of tiny primary TiO 2 nanocrystals. The specific surface areas of MC-1 and MC-2 are 119.5 and 132.4 m 2 /g respectively. The mesocrystals are potential photoanode materials in DSSCs, which can not only enhance the light scattering and dye adsorption, but also enhance the electron transport. The highest efficiency of 7.16% is achieved for the bi-layer NC-MC-2 DSSCs when the MC-2 is applied as a scattering layer on top of the nanocrystalline underlayer. The improvement of the efficiency is mainly attributed to the high specific surface area as well as the efficient light scattering, both of which result in the increase of light harvesting. Meanwhile, the electron transport of the photoanodes is also investigated. It is found that the electron transport of the single-crystalline-like mesocrystals is superior than nanoparticles, corresponding to the excellent energy conversion efficiency. [ABSTRACT FROM AUTHOR]

Luminescent organic dyes with tuning emission in widely visible gamut are still interesting challenging. Herein, we report two naphthalimide derivatives ( NAPP , NAPTPA ), which can output the variable emission colors covering the whole visible spectra from purple to far-red in aqueous solution. Both naphthalimide derivatives can exhibit bright emission in aqueous solution by introducing a phenyl ring into 4-site of naphthalimide, which acts as a π-bridge in delocalized system and not affects the intramolecular charge transfer process of naphthalimide dyes. Comparison with three analogues ( NAPDMP , NAPMOP and NAPDMA ), we evidenced the bright emissions in aqueous solution are from the amorphous emission different from the common crystal emission of naphthalimide dyes. We further fabricated the NAPP and NAPTPA into different nanoparticles matrixes to construct the multi-color toolbox, which could output four colors (purple, blue, green and red) in aqueous solution and yellow emission in crystal. Moreover, the white emission system was obtained through solution doping method. [ABSTRACT FROM AUTHOR]

Temperature-responsive fluorescence sensors have attracted great attention in recent years. Herein, we designed a series of AIE-based polymer sensors for monitoring the temperature in the physiological environment. In these polymers, a triphenylamine-naphthalimide chromophore (TPANIP) was used as the signal unit which can output the red emission in aggregated state. Different ratios of the temperature-responsive unit (NIPMAM) and the water-soluble unit (N -(2-(2-hydroxyethoxy)ethyl)methacrylamide, HEOEMA) were introduced to adjust the responsibility of the polymers in suitable temperature region and sensitivity. The structural and optical properties of all polymers were investigated by GPC, 1H NMR, FTIR, fluorescence spectroscopy and SEM. Among them, the polymer P1 (TPANIP / NIPMAM = 1/10) without the water-soluble unit shows the best sensing property. It performs a linear response to the temperature at the region of 15–50 °C in its aqueous solution with low concentration (0.5 mg/mL). By optimizing the work medium, polymer P1 can outputs the turn on signals with the increase of temperature. The enhanced emission mode is more suitable for the fluorescent detection that the turn off one. A series of AIE-based temperature-responsive polymers were synthesized with tuning responsibility towards temperature stimuli in the region of 0–65 °C via changing the working medium. [Display omitted] • Four tri-block polymers (P1-4) were synthesized with naphthalimide fluorophore. • P1-4 show red aggregation-induced emission in the aqueous solutions and solids. • P1-4 exhibit the tuning temperature-responsibility in the region of 0–65 °C. [ABSTRACT FROM AUTHOR]