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Organic–inorganic hybrid perovskite single crystals have attracted much attention due to their superior optoelectronic properties. Herein, we report a facile vapor-solution sequential route to prepare single-crystalline nanosheets of hybrid lead triiodide perovskite. It is found that this two-step deposition is able to fabricate sizeable high-quality single-crystalline nanosheets with no need of delicate control of crystallization conditions such as concentration or temperature for normal single crystal growth. The resulting perovskite nanosheets show good reproducibility and single crystallinity with bright and uniform photoluminescence. Our study provides a promising strategy for scalable fabrication of perovskite single crystals with great potential in optoelectronic applications.

An effective strategy to improve the efficiency of dye-sensitized solar cells (DSSCs) by infrared radiations (IR) and near infrared radiations (NIR) harvesting, using upconversion crystalline microrods NaYF4:Yb3+,Tm3+ is put forward. NaYF4:Yb3+,Tm3+ crystals were prepared with varying compositions of NaYF4, Yb3+ and Tm3+, and then in three different morphologies including small hexagonal microprisms, big hexagonal microprisms and hexagonal microrods for the investigation of the role of composition and morphology on upconversion efficiency. Thus, the crystals with efficient upconversion can be to screened out for doping with TiO2 photoanode of solar cells. Crystalline microrods, synthesized by hydrothermal method, show better upconversion as compared to microprisms prepared in two different sizes. On the other hand, these crystals also show downconversion. Addition of small amount of these microrods in TiO2 electrode of DSSCs increases light harvesting ability of photoanode TiO2 and consequently, photocurrent conversion efficiency is enhanced. Moreover these rare earth ions, being p-type dopant, raise the energy level of the TiO2 film and resultantly increase the photovoltage. Maximum power conversion efficiency 7.03% was achieved at an optimized proportion of NaYF4:Yb3+,Tm3+ in TiO2 (by weight). This 7.03% efficiency is 14.7% higher than the efficiency of pure TiO2 photoanode (6.13%). This improvement in efficiency can be credited to upconversion characteristics of doping material.

Molecular and supramolecular engineering is an effective approach to the modification of the optical properties of organic light emitting materials. Here, naphthalenyl groups have been introduced into the fluorenone backbone with different substitution positions to obtain target compounds 1-DNFO and 2-DNFO with modulated intermolecular interactions and self-assembly behaviors. Five crystal phases of the two compounds (three polymorphs for 1-DNFO and two polymorphs for 2-DNFO) have been obtained through careful tuning the operation parameters. Through the synergetic hydrogen bonds and van der Waals interactions, molecules are arranged in either centro- or noncentro-symmetric ways in these crystal phases to obtain very distinctive linear and nonlinear optical properties. Thermal analyses and variable temperature powder X-ray diffraction (VT-PXRD) measurements revealed thermally induced phase transitions between the polymorphs of 1-DNFO and 2-DNFO, respectively. The feasibility to control the morphologies and thus their linear and nonlinear optical properties, makes these kinds of crystals attractive for optoelectric applications.

Multimodal therapies have been regarded as promising strategies for cancer treatment as compared to conventional drug delivery systems that have various drawbacks in either low loading content, uncontrolled release, non-targeting or biotoxicity. We have developed a multifunctional three-dimensional tumor-targeting drug delivery system, Fe3O4@UIO-66-NH2/graphdiyne (FUGY), based on the hybridization of a novel two-dimensional material, graphdiyne (GDY), with a metal organic framework (MOFs) structure, Fe3O4@UIO-66-NH2 (FU). The FU MOF structure has superior ability for magnetic targeting, and was constructed by an in situ growth method in which it was surface-installed with GDY via amide bonds, as a carrier of anticancer drugs. The anticancer drug doxorubicin (DOX) was loaded onto FUGY and served as both an anticancer drug to treat the tumor and a fluorescence probe to ascertain the location of FUGY. The results show that FUGY exhibits a high drug loading content of 43.8% and an effective drug release around the tumor cells at pH 5.0. In particular, fluorescence imaging demonstrates that FUGY can deliver more anticancer drugs to tumor tissue than conventional drug delivery systems. Furthermore, FUGY exhibits superior therapeutic efficiencies with negligible side effects as compared to the direct administration of free DOX, both in vitro and in vivo. The obtained FUGY drug delivery system possesses ideal biocompatibility, sustained drug release, effective chemotherapeutic efficacy, and specific targeting abilities. Such a multimodal therapeutic system can facilitate new possibilities for multifunctional drug delivery systems.

While perovskite solar cells (PSCs) have recently experienced a rapid rise in power conversion efficiency (PCE), the prevailing PSCs still contain nondesirable defects in the interior and interface of the perovskite layer, which limits further enhancement in PCE and device stability. Herein, a new D-pi-A-type zinc pyridine porphyrin derivative (ZnPP) is synthesized and used as a passivation molecular via the antisolvent process for modifying the typical perovskite bulk thin film, leading to a new type of PSC with a graded passivation ofthe perovskite layer. Impressively, it is found that ZnPP treatment significantly improves the quality of perovskite films and reduces charge transport losses through passivating the uncoordinated Pb2+ cations, yielding devices with a high efficiency of 21.08% with fill factor (FF) of 82.91% and demonstrating the promise of integration of perovskite bulk thin films with tailor molecular via graded modification.

As a novel two-dimensional material consisting of sp- and sp2-hybridized carbon atoms, graphdiyne (GD) shows great potentials in the field of electric and material science. In particular, the performance is reported to be significantly improved for GD-involved optoelectronic devices due to its excellent electronic properties. Herein, to facilitate the charge transfer process and further improve the photo-to-electricity conversion efficiency (PCE) for dye-sensitized solar cells (DSSCs), for the first time we introduced GD in the TiO2(P25)-based photoanodes of DSSCs, resulting in GD-doped TiO2 photoanodes. It was shown that the overall performance of the GD-doped cell is significantly enhanced due to the higher dye adsorption amount, faster electron transfer and lower recombination, compared to that of the undoped DSSC. Furthermore, the optimum GD doping amount (weight percent, wt%) was determined. Thus, the DSSC involving P25-0.6 wt% GD photoanode achieved the best PCE of 8.03%, which increased by 26.5% comparing with that of pure P25 film-based cell.

Molecular engineering toward decreasing the band gap and thus extending the absorption spectrum of benzotriazole-based dye is a challenge. Herein, the benzotriazole structure is finely tuned by fusing another electron deficient ring to the benzo unit leading to a series of benzotriazole-based electron-withdrawing heterocyclic rings including benzobitriazole, benzotriazolequinoxaline and benzotriazolethiadiazole. These together with benzotriazole are incorporated into the π-bridge, respectively, as an auxiliary acceptor between the triphenylamine donor and the cyanoacrylic acid anchoring group for the construction of donor-auxiliary acceptor-π-acceptor type sensitizers (LC-2, LC-3, LC-4 and LC-5). The benzobitriazole, benzotriazolequinoxaline and benzotriazolethiadiazole units show greatly increased electron-withdrawing capability and the corresponding sensitizers (LC-3, LC-4 and LC-5) exhibit broadened spectral response range compared to the reference benzotriazole-based dye LC-2 due to the decreased energy gap. Thus, the LC-3 and LC-4 cells exhibit significantly enhanced photocurrent density (Jsc) values due to the greater light-harvesting abilities compared to LC-2. However, the electrochemical impedance analysis suggests the electron lifetime and charge recombination resistance are decreased due to the introduction of benzobitriazole, benzotriazolequinoxaline and benzotriazolethiadiazole, resulting in a slight loss of open-circuit voltage (Voc). The findings provide a guidance for the future molecular design of highly efficient organic sensitizers for use in dye-sensitized solar cells.

Two gluconic acid derivatives C3 and C6 bearing a terpyridyl moiety were designed and synthesized. Thanks to the hydrophilic interaction from glucosyl moiety, C3 and C6 can dissolve in polar solvents and gel aromatic solvents with a critical gel concentration of weight 1.5%. The solution consisting of organic ligand C3 as sensitizer and Ln(III) ions as emitters can realize white light emission with thermo- and chemical stimuli-response properties in luminescence spectra. Further, the self-assemblies of C3 and C6 were examined by the combination of the theoretical calculations via hybrid density functional theory (DFT) with 1H nuclear magnetic resonance (1HNMR) and powder X-ray diffraction (PXRD) analysis. The study actually provides a reliable method for the formation of potential functional smart materials.

Targeted synergistic therapy has broad prospects in tumor treatments. Here, a multi-functional nanodrug GDYO-CDDP/DOX@DSPE-PEG-MTX (GCDM) based on three traditional anticancer drugs (doxorubicin (DOX), cisplatin (CDDP) and methotrexate (MTX)) modified graphdiyne oxide (GDYO) is described, for diagnosis and targeted cancer photo-chemo synergetic therapy. In this system, for the first time, these three traditional anti-cancer drugs have played new roles and can reduce multidrug resistance through synergistic anti-tumor effects. Cisplatin can be hybridized with GDYO to form a multifunctional and well-dispersed three-dimensional framework, which can not only be used as nano-drug carriers to achieve high drug loading rates (40.3%), but also exhibit excellent photothermal conversion efficiency (47%) and good photodynamic effects under NIR irradiation. Doxorubicin (DOX) is loaded onto GDYO-CDDP through π-π stacking, which is used as an anticancer drug and as a fluorescent probe for nanodrug detection. Methotrexate (MTX) can be applied in tumor targeting and play a role in synergistic chemotherapy with DOX and CDDP. The synthesized multi-functional nanodrug GCDM has good biocompatibility, active targeting, long-term retention, sustained drug release, excellent fluorescence imaging capabilities, and remarkable photo-chemo synergistic therapeutic effects.

Photodynamic therapy (PDT) has a successful track record in cancer. . Urea is a naturally occurring metabolite in the human body. Some studies have shown that it can inhibit the proliferation of tumor cells and cause oxidative stress. In order to explore the application of urea in enhancing the PDT effect, we synthesized a new photosensitizer (BODIPY-I-35) with good phototherapeutic effect and encapsulated it in liposomes. Compared with free BODIPY-I-35, water-soluble nanoliposomes (LipoBOD) produced a huge redshift ( 122 nm) of fluorescence emission in solution. When LipoBOD was irradiated with 808 nm laser (1 W/cm

Perovskite solar modules have been attracting increasing attention due to their market potential, yet publications concerned with theintrinsic scale-up potential of different perovskite compositions remain relatively scarce. On the other hand, while great success is being made towards improving the power conversion efficiency (PCE) of perovskite solar cells (PSCs) by cesium cation (Cs+) doping of the perovskite, more attention is being paid to the perovskite phase stabilization effect of Cs+ doping, and less to other properties that are critical to understand and futher improve the PSC’s. In this work, moderately-Cs-doped MAPbI3 was employed as a model perovskite material in order to exclude the phase stabilization effect. Our systematic study revealed the influence of Cs+ in organic-inorganic hybrid perovskites on the crystal structure, crystallization process, trap state density, band structure and charge (i.e., ions or photo-carriers) transport. Markedly, it has been observed that Cs+ doping can greatly increase the carrier diffusion length in the perovskite films, thus improving the potential to scale-up PSC’s.The PCE of small area devices (0.09 cm2) was increased to 21.72% from 19.73%, with decreased hysteresis behavior and increased operational stability (T85 = 1000 h) after Cs+ doped, where T85 refers to the retention of 85% of the initial PCE. Moreover, a PCE of 21.08% was obtained for a Cs+-containing perovskite module with an active area >30 cm2, which demonstrates a better “reproducibility” than the reference sample (MAPbI3-based perovskite modules, PCE = 18.26%).

Interfacial adsorption configuration plays a crucial role in influencing the photovoltaic performance of dye-sensitized solar cells (DSSCs), and thus, theoretical investigations are needed to further understand the impacts of different absorption configurations on stoichiometric and defective TiO2(101) surfaces on the short-circuit photocurrent density (JSC) and open-circuit voltage (VOC) of DSSCs. Herein, calculations of isolated dyes and dye/TiO2 systems were performed on the donor-π bridge-acceptor (D-π-A) type porphyrin sensitizers bearing different donor moieties and an α-cyanoacrylic acid anchoring group (T1-3), using DFT and TD-DFT methods. And, for the first time, comparative analysis of interfacial electron transfer (IET) and density of states (DOS) were carried out on dye/TiO2 systems with stoichiometric and defective surfaces to provide further insight into the electronic factors influencing the efficiency of DSSCs, which can well explain the experimental variation trends of JSC and VOC values. It turned out that attachment via the carboxyl and cynao groups in a tridentate binding mode can result in more efficient IET rates and an upshifted conduction band in comparison with those of the bidentate attachment. More interestingly, we found that the adsorption configuration on defective surfaces containing an O2c vacancy induced more upshifted CBM and relatively fast IET, especially for the bonding mode through two O atoms of the carboxyl group.

Human motion capture is widely used in exoskeleton robots, human-computer interaction, sports analysis, rehabilitation training, and many other fields. However, soft-sensor-based wearable dynamic measurement has not been well achieved. In this paper, the dynamic measurements of legs were investigated by using dielectric elastomers as stain sensors, and an alternating signal was applied to detect the dynamic rotational angles of the legs. To realize a quick response, parameters of the sensors were optimized by circuit analysis. The sensor can detect hip, knee, and ankle joint motions with a sample frequency of 200 Hz. The measurements of the sensors were compared with a commercial motion capture system from PhaseSpace, and dynamic errors between them were smaller than 3° when squatting and walking at low speed and smaller than 5° when walking at high speed. Experiments therefore demonstrate the feasibility of the integrated wearable stretch sensors with pants.

Reverse micellar systems possess a characteristic nanoscale water-in-oil (w/o) structure and can offer mild conditions as a unique and versatile reaction medium. Reverse microemulsions containing water/TX-100 + hexanol/hexane are studied in this work through experimental techniques and simulation methods. Surfactant dosages and water amount affect the micellar structure profoundly, and the polydispersity of the surfactant molecules affects the micellar structure remarkably. TX-100 with 9-10 EO units can form micelles in a simply piling way, while TX-100 with 5-10 EO units endows the micelles with a hierarchical micellar interface and a more compact structure, leading to monodisperse micelles with a smaller diameter. Water in the polar cores has three states. In the reverse micellar system using TX-100 with 9-10 EO units, hydrolysis of tetraethoxysilane happens rapidly and the formed silica gels are apt to aggregate, resulting in polydisperse silica nanoparticles. For the micellar system using TX-100 with 5-10 EO units, the micellar hierarchical distributed interface facilitates the material exchange of tetraethoxysilane and limits the hydrolysis of tetraethoxysilane inside the micelles, providing monodisperse silica nanoparticles.

All-inorganic lead halide perovskites demonstrate improved thermal stability over the organic–inorganic halide perovskites, but the cubic α-CsPbI3 with the most appropriate bandgap for light harvesting is not structurally stable at room temperature and spontaneously transforms into the undesired orthorhombic δ-CsPbI3. Here, we present a new member of black-phase thin films of all-inorganic perovskites for high-efficiency photovoltaics, the orthorhombic γ-CsPbI3 thin films with intrinsic thermodynamic stability and ideal electronic structure. Exempt from introducing organic ligands or incorporating mixed cations/anions into the crystal lattice, we stabilize the γ-CsPbI3 thin films by a simple solution process in which a small amount of H2O manipulates the size-dependent phase formation through a proton transfer reaction. Theoretical calculations coupled with experiments show that γ-CsPbI3 with a lower surface free energy becomes thermodynamically preferred over δ-CsPbI3 at surface areas greater than 8600 m...

In this study, graphdiyne (GD)-hybridized nitrogen-doped TiO2 nanosheets with exposed (001) facets (GD-NTNS) have been prepared via a hydrothermal reaction and utilized as photocatalyst for the photodegradation of rhodamine B (RhB) under visible light illumination. The resultant GD-NTNS composites exhibit superior visible light photocatalytic activity than that of the bare TiO2 nanosheets (TNS) and nitrogen-doped TiO2 nanosheets (NTNS). The enhanced photoactivity can be attributed to the synergistic effects of GD and nitrogen doping with efficient electron transfer and strong visible light absorption. It has been revealed that ·O2− and h+ are the major species for the enhanced photoactivity under visible light. Our work will facilitate the potential for future design of hybrid materials for practical applications beyond photocatalysts.

A novel fluorescent probe was constructed by the self-assembly of monosubstituted BODIPY and a novel targeted hydrophobin named hereafter as HFBI-RGD. Optical measurements and theoretical calculations confirmed that the spectral properties of the probe were greatly influenced by the BODIPY structure, the appropriate volume of BODIPY and the cavity of HFBI-RGD. The experiments in vivo and ex vivo demonstrated that the probe had excellent ability for tumor labelling.

Fluorescent probes have been demonstrated to be promising candidates as biomarkers and biological carriers. Our study focuses on the development of a novel amphiphilic fluorescent probe with good photostability, high water solubility, excellent specificity and promising loading capability for tumor diagnosis and treatment. At first, BODIPY dye and O-carboxymethyl chitosan were prepared via a chemical reaction. Then, the prepared BODIPY dye and cRGD were bonded to O-carboxymethyl chitosan successively via an acylation reaction. Finally, we obtained the desired amphiphilic fluorescent probe: BODIPY–O-CMC–cRGD, which was based on the fluorescence resonance energy transfer (FRET) principle for selective visualization of tumors in vitro. Through a series of experiments, we found that this fluorescent probe possessed better fluorescence characteristics and tumor targeting properties. Simultaneously, by self-assembly, the amphiphilic probe encapsulated the other flexible structure of BODIPY2 and the rigid structure of porphyrin, which formed distinct nanoparticles with different particle sizes. Hence, we could observe different phagocytosis processes of the two nanoparticles in the tumor cells via the fluorescence of dyes by confocal laser scanning microscopy. Therefore, the results suggest that the fluorescent probe has advantages in tumor detection, and the constructed tumor-specific nanoparticles show high clinical potential to be utilized not only in visual and precise diagnosis but also in excellent drug delivery for tumor treatment. Henceforth, we will prepare new targeted and visualized pharmaceuticals by replacing BODIPY2 and porphyrin with antineoplastic drugs for future tumor treatment.

Several different quantities of Ce/TiO2 materials were synthesized in the same condition by a wet method. Dye-sensitized solar cells (DSSCs) were fabricated by using porous Ce/TiO2 film electrodes derived from P25 nanoparticles. Various techniques such as X-ray diffraction, Scanning electron microscope and Brunauer-Emmett-Teller are used to characterize the products. The short-circuit current density and photo-electric conversion efficiency reach optimum values: 13.87 mA cm−2 and 7.00% respectively when the amount of Ce(NO3)3·6H2O is 0.050 g/1 g P25, which may be attributed to better transportation of electrons and more adsorption of dyes and sunlight.

Low water solubility and poor selectivity are two fundamental limitations that compromise applications of near-infrared (NIR) fluorescent probes. Methods: Here, a simple strategy that can resolve these problems simultaneously was developed by using a novel hybrid protein named RGD-HFBI that is produced by fusion of hydrophobin HFBI and arginine-glycine-aspartic acid (RGD) peptide. This unique hybrid protein inherits self-assembly and targeting functions from HFBI and RGD peptide respectively. Results: Boron-dipyrromethene (BODIPY) used as a model NIR dye can be efficiently dispersed in the RGD-HFBI solution by simple mixing and sonication for 30 min. The data shows that self-assembled RGD-HFBI forms a protein nanocage by using the BODIPY as the assembly template. Cell uptake assay proves that RGD-HFBI/BODIPY can efficiently stain αvβ3 integrin-positive cancer cells. Finally, in vivo affinity tests fully demonstrate that the soluble RGD-HFBI/BODIPY complex selectively targets and labels tumor sites of tumor-bearing mice due to the high selectivity of the RGD peptide. Conclusion: Our one-step strategy using dual-functional RGD-HFBI opens a novel route to generate soluble and targeted NIR fluorescent dyes in a very simple and efficient way and may be developed as a general strategy to broaden their applications.

The facile synthesis of electrophoretic particles for electrophoretic displays (EPDs) with fast response and precise image control is a challenge. In this work, monodisperse silica nanoparticles were prepared by a sol-gel process in reverse microemulsion combined with solvent-thermal treatment, and modified with ionic liquid. The silica nanoparticles before and after surface modification are all monodisperse and smooth spheres. They also own suitable densities and excellent chromaticity for EPDs. The structure of ionic liquid modifiers shows remarkably influence on surface property and electrophoretic property of modified silica nanoparticles. The modified silica nanoparticles show improved hydrophobicity favoring for dispersion stability and suspension stability in the dispersant. The surface charge performance of modified silica nanoparticles are depending on competitive cooperation between ion pairs and alkyl groups of ionic liquids, and can be adjusted through tuning ionic liquid structure. The fabricated EPD prototypes show response time of 180–191 ms in the electrophoretic display cell with 0.2 mm thickness, much faster than the commercial EPDs.

Summary Organic-inorganic metal-halide perovskite solar cells (PSCs) have achieved a certified power-conversion efficiency (PCE) of 25.5%. However, long-term stability and air stability of the PSCs are still major concerns and hamper commercialization. Herein, we employ a multi-functional ionic liquid (IL), 1,3-bis(cyanomethyl)imidazolium bis(trifluoromethylsulfonyl)imide ([Bcim][TFSI]), which contains an imidazolium cation functionalized with nitrile (CN) groups and the TFSI anion and is, additionally, able to form an extensive network of low-barrier H bonds, as an additive in perovskite-precursor solutions. Because of a combination of the Lewis-basic CN groups and the hydrophobic TFSI anion in the IL, highly crystalline perovskite films with large grain sizes are obtained. The IL-modified perovskite films afford PSCs with long-term stability and PCEs > 21%. The stability of unencapsulated devices retain >95% of their original efficiency after 1,000 h of aging. This study demonstrates the considerable potential of TFSI-based ILs to improve the performance of PSCs.

Cyanine dyes are widely used in the field of tumor phototherapy due to their excellent photophysical properties. To explore the heavy atoms effects on the photothermal and photodynamic performance of phototherapeutic agents, chlorine, bromine, and iodine were introduced to synthesize a series of cyanine dyes (IR6, IR7, and IR8). We have found that all halogenated cyanine dyes exhibited high excitation wavelength (around 800 nm) and low dark toxicity. Among them, IR8 behaved the best singlet oxygen production ability in the three dyes. For photothermal performance, IR8 exhibited the best photothermal conversion rate (46.6%), photothermal stability, and excellent therapy efficiency (half-maximal inhibitory concentration, IC50 = 16.2 μg/mL). IR7 behaved a greater enhancement of the photothermal conversion rate (43.4%) than IR6 (42.3%). In conclusion, the heavy atoms effects on the photothermal and photodynamic properties of cyanine dyes are positively correlated with the increase of the atomic number of the halogen atom, and the iodine atom may be the most worthy of consideration in the all halogen atoms.

Covalent organic frameworks (COFs), constructed with the light atoms such as carbon, nitrogen, oxygen, borane etc. via covalent bonds, represent a promising class of structurally ordered, highly crystalline functional porous materials possessing a large surface area to volume ratio. Recently there is a rapidly growing interest in tetrapyrrolic macrocycle-based COFs in which naturally occurring porphyrin and the synthetic analogs of porphyrin such as corroles and phthalocyanines, generally referred to as porphyrinoids, are employed as building blocks. Due to the intriguing properties of porphyrin and porphyrinoid units, the resulting COFs have found applications in different areas such as in gas absorption, storage of energy, optoelectronics, and catalysis. Herein, we review the research progress achieved in these areas over the past 5 years. The design and synthesis of porphyrin and porphyrinoid COFs will first be discussed, and is followed by an examination of the recent advances in their applications. The prospects and challenges for the further development of porphyrin and porphyrinoid COFs from design to applications will be highlighted.

The combination of chemotherapy and photodynamic therapy has been proved to be a promising therapy for drug-resistant cancers. In this study, we report, for the first time, a novel two-fold interpenetration pillar-layered metal-organic frameworks (MOFs) material, using BODIPY-derivate bipyridine as linker and Photosensitizer (PS), named BBP-MOFs, was successfully synthesized to serve as a drug carrier and Photodynamic agent simultaneously. The BBP-MOFs could generate singlet oxygen (1O2) to perform PDT under 660 nm light irradiation, in the meantime, the anticancer drugs doxorubicin (DOX) could be loaded for chemotherapy. The results showed that BBP-MOFs exhibited a high drug loading content of 49.7% a controlled drug release and ideal biocompatibility. This DOX loaded BBP-MOFs was readily taken up by HeLa cells, and high levels of 1O2 were generated under light irradiation. This work provided strong evidence for BBP-MOFs as a promising new anticancer drug carrier and PDT candidate, the PDT and chemotherapy combined synergistic therapy revealed high therapeutic efficacy for cancer cells.

Complexation of group 11 metal cations with an -bis(phenylthio)-substituted trans-doubly N-confused porphyrin (trans-N2CPSPh: 4) afforded a series of square planar trivalent organometallic complexes (i.e., Cu-H4, Ag-H4, and Au-H4). The X-ray crystal structures of the complexes revealed highly planar core geometries along with the presence of peripheral amine and imine nitrogen sites of the pyrrolic moieties. NMR, UV-vis absorption, and magnetic circular dichroism (MCD) spectroscopies suggested the 18 -electron aromaticity of the complexes. The aromaticity was also fully analyzed by various theoretical methodologies such as NICS and ACID calculations. The central metal affected on the amphiprotic character of the complexes possessing both pyrrolic amino-nitrogen and imino-nitrogen at the periphery, which was examined by the photometric titration with trifluoroacetic acid (TFA) and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), respectively. The inherent acidity of the complexes was followed in the order; Cu-H4 > Au-H4 > Ag-H4 and that of basicity was Au-H4 > Ag-H4 > Cu-H4. The complexes could be considered as a structural motif of expanded imidazole.

Three new D–A–π–A configuration organic dyes ( LC-6 , LC-7 and LC-8) based on triphenylamine as the electron donor, benzoselenadiazole (BSD) as the auxiliary acceptor, either thiophene or benzene as the π spacer and cyanoacetic acid as the anchoring group have been designed and synthesized for dye-sensitized solar cells (DSCs). Introduction of octyloxy chain on the triphenylamine unit was found to be able to redshift the absorption spectra and suppress the charge recombination. It was also found that using the benzene instead of thiophene as π spacers and using CDCA coadsorbent could help to improve the J sc and V oc values of the cell. Under standard global AM 1.5 solar light conditions, a DSC employing a dye with a 1,4-phenylene unit with CDCA gave the best photovoltaic performance with a J sc of 13.21 mA cm −2 , a V oc of 734 mV, a FF of 0.69 and an overall PCE of 6.72%. These results suggest that the BSD unit can be a promising electron-withdrawing candidate in D–A–π–A type sensitizers for further exploration DSCs.

Three-dimensional TiO2 microspheres doped with N were synthesized by a simple single-step solvothermal method and the sample treated for 15 h (hereafter called TMF) was then used as scattering layers in the photoanodes of dye-sensitized solar cells (DSSCs). The TMF was characterized using scanning electron microscopy, high resolution transmission electron microscopy, Brunauer-Emmett-Teller measurements, X-ray diffraction, and X-ray photoelectron spectroscopy. The TMF had a high surface area of 93.2 m2∙g–1 which was beneficial for more dye-loading. Five photoanode films with different internal structures were fabricated by printing different numbers of TMF scattering layers on fluorine-doped tin oxide glass. UV-vis diffuse reflection spectra, incident photon-to-current efficiencies, photocurrent-voltage curves and electrochemical impedance spectroscopy were used to investigate the optical and electrochemical properties of these photoanodes in DSSCs. The presence of nitrogen in the TMF changed the TMF microstructure, which led to a higher open circuit voltage and a longer electron lifetime. In addition, the presence of the nitrogen significantly improved the light utilization and photocurrent. The highest photoelectric conversion efficiency achieved was 8.08%, which is much higher than that derived from typical P25 nanoparticles (6.52%).

A porphyrin modified by glycine has been synthesized and developed as a near-infrared (NIR) fluorescence probe to detect tumor. Porphyrins’ longwavelength emission at ∼650 nm can efficiently avoid the spectral crosstalk with Spontaneous fluorescence in the visible light region. A disulfide-based cyclic RGD peptide named iRGD c (CRGDKGPDC), a tumor homing peptide, harbors a cryptic C-end Rule (CendR) motif that is responsible for neuropilin-1 (NRP-1) binding and for triggering extravasation and tumor penetration of the peptide to improve the imaging sensitivity and therapeutic efficacy. We used N − hydroxy succinimide as an activator to introduce the glycine methyl ester to detect tumor. We got a porphyrin modified by glycine. The affinity between probe and tumor cell entered GLC-82 cells (human glandular lung cancer cell line) can be observed by Confocal Microscope. The toxicity of probe has been identified by MTT Assay. The summary has been gotten that the porphyrins were nontoxic to GLC-82 cells and glycine modified porphyrin has a good affinity with GLC-82 cells under the iRGD function by our experiment.

The β-functionalized porphyrin containing an additional electron-withdrawing unit, 2,3-diphenylquinoxaline( DPQ ) for LP-5 or 2,1,3-benzothiadiazole ( BTD) for LP-6 with different electron-withdrawing abilities, between the porphyrin core and the anchoring group and the reference porphyrin dye ( LP-4 ) have been designed and synthesized for DSCs. The influence of the additional electron-withdrawing units on molecular properties as well as photovoltaic performance of the corresponding DSCs was investigated systematically. Compared with LP-4 , the introduction of additional electron-deficient unit at the porphyrin β π-linker in LP-5 and LP-6 decreases the lowest unoccupied molecular orbital (LUMO) energy levels, resulting in the broader absorption spectra and significantly improved IPCE spectra in the region 350–500 nm, which ensures the better light-harvesting properties and the higher short-circuit current density ( J sc ). On the other hand, the introduction of additional acceptors of LP-5 and LP-6 induces dye aggregation and reduces the lifetime of the charge–separated states, which decreases the open–circuit voltage ( V oc ). Interestingly, the loss in V oc is overcompensated by the improvement in J sc . The study provides not only an alternative approach to design novel porphyrin sensitizers, but also an insight into how to manipulate the LUMO energy levels of porphyrin sensitizers via the β-linker modifications for the optimal photovoltaic applications.

The performance of dye-sensitized solar cells (DSSCs) consisting of anatase TiO2 nanoparticles that were synthesized via a hydrothermal method was studied. The synthesized TiO2 nanoparticles were characterized by X-ray diffraction (XRD), nitrogen sorption analysis, scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), and UV–vis spectroscopy. Then the J-V curve, electrochemical impedance spectroscopy (EIS), and open-circuit voltage decay (OCVD) measurement were applied to evaluate the photovoltaic performance of DSSCs. Compared with the commercial TiO2 nanoparticles (P25), the synthesized-TiO2 nanoparticles showed better performance. By adding diethylene glycol (DEG) before the hydrothermal process, the synthesized TiO2 nanoparticles (hereafter referred to as TiO2-DEG particles) shows narrower size distribution, larger specific surface area, higher crystallinity, and less surface defects than TiO2 (DEG free) particles. The analysis of photovoltaic properties of DSSCs based on TiO2-DEG particles showed that the recombination of electron-hole pairs was decreased and the trapping of carries in grain boundaries restrained. It was believed that the photoelectrode fabricated with the as-prepared TiO2 nanoparticles improved the loading amount of dye sensitizers (N719), and enhanced the photocurrent of the DSSCs. As a result, the TiO2-DEG particle based cells achieved a photo-to-electricity conversion efficiency (η) of 7.90%, which is higher than 7.53% for the cell based on TiO2 (DEG free) and 6.59% for the one fabricated with P25.

The sintered TiO2 nanofilms were immersed in the aqueous solution of graphite oxide and then were thermally reduced to reduced graphene oxide (RGO), resulting in RGO-doped TiO2 photoanodes employed in the dye-sensitized solar cells (DSSCs). This preparation method for the reduced graphene oxide–TiO2 (RGO–TiO2) photoanode could avoid the loss of RGO during the sintering process. The presence of RGO in the photoanodes was confirmed using Raman analysis, scanning electron microscopy, transmission electron microscopy, and energy-dispersive spectrometer. The amount of RGO in photoanode was obtained by thermo-gravimetric analysis. Other techniques such as X-ray diffraction, Brunauer–Emmett–Teller, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy were used to characterize the composite materials of RGO–TiO2. The J–V measurement of RGO–TiO2-based DSSCs showed that the best photoelectric conversion efficiency (η) of 6.85% is 11.7% higher than that of the pure TiO2 (P25–TiO2)-based DSSCs. It was shown that RGO in the photoanode could facilitate the phase transition in TiO2 crystals (from anatase to rutile) resulting in the mixed crystals in the photoanodes. The existence of RGO and mixed-crystal structure of TiO2 changed the electronic transmission pathway, reduced the recombination rate of electron–hole pairs, and thus improved the η of DSSCs.

A new coloured polymer particle was prepared, in which chromophoric groups were introduced onto the surface of the polymer particle for use in electronic ink. The structure, morphology and thermal stability of polymer electrophoretic particles were characterized using FTIR, solid state 13C-NMR, SEM and TGA. Electrophoretic mobility measurements proved that the polymer particles had negative charges in the electrophoretic dispersion medium. Electronic ink microcapsules containing the polymer particles were prepared by coacervation. The polymer particles had a reversible electric response in the microcapsules under a DC electric field.

How to graft co-sensitizers with different binding strengths onto TiO2 surfaces for enhancing the performance of dye-sensitized solar cells (DSSCs) has not been discussed very much. Herein a ruthenium-based sensitizer (N719) and a porphyrin molecule (LP-2) with complementary absorption spectra (300–750 nm) have been chosen to investigate how the dye loading procedure would influence the photovoltaic performance of co-sensitized solar cells. Interestingly, it is found that 54.7% of the loading amounts of pre-adsorbed LP-2 are replaced by the post-adsorption of N719. The replacement adsorption is not observed when the two molecules are loaded in reverse order, which is attributed to their different adsorption configurations and binding energies. The competitive adsorption between co-sensitizers is thus systematically investigated by UV-visible absorption spectroscopy, energy dispersive spectrometry (EDS) and electron probe microanalysis (EPMA). Upon optimization, the device sequentially sensitized with LP-2 and N719 exhibits efficiency (7.72%) enhancement of 38.6% and 18.0% compared with those fabricated with single LP-2 and N719, respectively. The results provide a new vision on the stepwise sensitization of TiO2 films using co-sensitizers with a difference in adsorption properties, suggesting that complementary spectral absorption of co-sensitizers can lead to excellent cell performance by choosing an appropriate dye loading procedure.

The development of efficient catalysts with a visible-light response is of great importance in photocatalysis. Porphyrinic metal-organic frameworks (porph-MOFs) have recently been shown as promising photocatalyst candidates due to their large surface area, high visible light harvesting efficiency, and semiconductive properties, but challenges still remain because of their rapid charge recombination. Herein, we report the design of an effectively visible-light-driven composite material, namely TP-222(Zn), containing zirconium-based porph-MOF PCN-222(Zn) linked TiO2 nanoparticles (NPs) via the compound 4-mercaptopyridine which is axially bonded to the porphyrin central Zn metal in the PCN-222(Zn) and anchored onto the surface of TiO2 NPs. The resulting composite material demonstrates the high dispersion of TiO2 NPs and their close contact with the porph-MOF matrix, and serves as an effective photocatalyst for degrading organic contaminants under visible light irradiation due to their synergistic effect. It is further confirmed by fluorescence spectroscopy and electrochemical impedance spectroscopy that the remarkably enhanced photocatalytic activity of the TP-222(Zn) composite is attributed to the efficient charge separation with electron injection from PCN-222(Zn) to TiO2 NPs. In addition, the TP-222(Zn) composite shows excellent stability and recyclability as a result of the axially coordinative interaction between TiO2 NPs/PCN-222(Zn) and the 4-mercaptopyridine. Overall, this work provides a new strategy for the fabrication of highly efficient porph-MOF-based composite materials for visible light-driven photocatalysis.

Based on gluconic acid acetal and terpyridyl groups, we have prepared two new supramolecular gelators C3S and C6S with the critical gelation concentrations of 0.1% in aryl halides and the ability of gelling in DMF/DMSO + H2O at room temperature. The excellent self-healing properties of the gels were studied using rheological experiments. Based on the 1H NMR, IR spectrum and PXRD, the self-assembly pattern of C6S was proposed through theoretical calculation. After coordinating with Ln(III) metal ions, the multicolor luminescent metallogel C6S–Eu/Tb was investigated. The luminescence properties of the gels were characterized by fluorescence spectroscopy and fluorescence lifetime measurements, confirming the energy transfer between the organic compounds and Ln(III) metal ions.

The efficiency of perovskite solar cells based on mesoscopic TiO2 has been soaring over the past three years and is expected to reach over 25% by engineering the composition of perovskite and interface layers. Efforts to increase the power conversion efficiency (PCE) of planar junction perovskite solar cells have been made from different perspectives. For the first time, we use the wormhole-like hexagonal mesoporous silica (HMS) to modify the substrate surface inside the planar junction perovskite solar cell to improve efficiency. The formed random islands of HMS decreased the loading of the perovskite layer, leading to abnormal growth of perovskite and increased light path length. Using HMS islands in a planar heterojunction device, we realized an average PCE of 17.6% over 30 devices, which is higher than that of the controlled intrinsic planar heterojunction device (15.85%).

The introduction of an additional acceptor to a typical donor-π bridge-acceptor (D-π-A) type porphyrin sensitizer results in a D-A-π-A featured porphyrin. Two porphyrins containing an additional acceptor with different electron-withdrawing abilities such as 2,3-diphenylquinoxaline ( DPQ ) for LP-11 and 2,1,3-benzothiadiazole ( BTD ) for LP-12 between the porphyrin core and the anchoring group have been synthesized for use as sensitizers in dye-sensitized solar cells (DSCs). Compared to LP-11 , LP-12 with the stronger electron-withdrawing additional acceptor BTD possesses better light harvesting properties with regard to red-shifted Q-band absorption and a broader IPCE spectrum, resulting in a greater short circuit photocurrent density ( J sc ) output. Interestingly, the steric hindrance of the DPQ group is favorable for suppressing dye aggregation, leading to a larger open-circuit voltage ( V oc ) value for LP-11 -based cell. However, the loss in V oc of LP-12 is overcompensated by an improvement in J sc . The optimized cell based on LP-12 achieves the better performance with a J sc of 15.51 mA cm −2 , a V oc of 674 mV, a fill factor (FF) of 0.7 and an overall power conversion efficiency (PCE) of 7.37% under standard AM 1.5 G irradiation. The findings provide a guidance for the future molecular design of highly efficient porphyrin sensitizers for use in DSCs.

Interfacial engineering of the meso-TiO2 surface through a modified sequential deposition procedure involving a novel PbI2–HMPA complex pretreatment is conducted as a reproducible method for preparing MAPbI3 based perovskite solar cells providing the highest efficiencies yet reported with the polymer HTM layer. Grazing-incidence X-ray diffraction depth profiling confirms the formation of a perovskite film with a PbI2-rich region close to the electron transport layer (ETL) due to the strong interaction of HMPA with PbI2, which successfully retarded the dissolution of the PbI2 phase when depositing the perovskite layer on top. These results are further confirmed by energy-dispersive X-ray spectroscopy performed in a scanning transmission electron microscope, which reveals that the I/Pb ratio in samples treated with the complex is indeed reduced in the vicinity of the ETL contact when compared to samples without the treatment. The engineered interface leads to an average power conversion efficiency of 19.2% ...

A novel polymer gel electrolyte was used to improve the performance and long-term stability in dye-sensitized solar cells (DSSCs). The polymer gel electrolyte (PGE) was prepared by mixing 5 wt% poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and 2 % TiO2 nanoparticles. The conductivity of PGE with P25 reached 9.98 × 10−3 S/cm, which increased by 34.9 % compared with 7.40 × 10−3 S/cm of PGE without P25, and the diffusion coefficient was also increased by 19.0 %. Different photoelectrodes were obtained by using three kinds of surfactants (cetylamine, octadecylamine, and P123) as pore-forming materials, and their morphologies were contrasted through scanning electron microscopy (SEM). The results showed that gel electrolyte can increase the short-circuit current density (J sc) from 11.01 to 12.99 mA/cm2 in DSSCs. Moreover, unlike the liquid electrolyte, the gel electrolyte is more conducive to the TiO2 photoelectrodes with larger pores. In conclusion, the efficiency of DSSC with gel electrolyte and P123 as pore-forming material was 6.73 %, which was 12 % higher than the liquid electrolyte in the same test condition. In addition, the sealed gel electrolyte DSSCs showed better stability than did liquid electrolyte DSSCs during nearly 600 h.

Dye-sensitized solar cells (DSSCs) have attracted much interest during the past few decades. However, it is still a tremendous challenge to identify organic molecules that give an optimal power conversion efficiency (PCE). Here, we apply our recently developed, inverse-design method for this issue with the special aim of identifying porphyrins with promisingly high PCE. It turns out that the calculations lead to the prediction of 15 new molecules with optimal performances and for which none so far has been studied. These porphyrin derivatives will in the near future be synthesized and subsequently tested experimentally. Our inverse-design approach, PooMa, is based on the strategy of providing suggestions for molecular systems with optimal properties. PooMa has been developed as a tool that requires minimal resources and, therefore, builds on various approximate methods. It uses genetic algorithm to screen thousands (or often more) of molecules. For each molecule, the density-functional tight-binding (DFTB) method is used for calculating the electronic properties. In the present work, five different electronic properties are determined, all of which are related to optical performance. Subsequently, a quantitative structure-property relationship (QSPR) model is constructed that can predict the PCE through those five electronic properties. Finally, we benchmark our results through more accurate DFT calculations that give further information on the predicted optimal molecules.

In this work, four intramolecular charge transfer (ICT) compounds, TBT, TVBVT, TSBST and TSVBVST, with difluoroboron β-diketonate as the electron acceptor, triphenylamine unit as the electron donor and different π-conjugated bridges have been synthesized. The linear absorption and emission spectra in different organic solvents indicate a positive solvato-chromism. The multilinear regression analyses of the linear optical spectra in different solvents indicate that the solvato-chromism is mainly caused by the polarity/dipolarity properties of the solvents and possibly the halogen-halide interaction. Time-dependent density functional theory (TD-DFT) calculations were used to investigate the charge density difference between the ground and excited states of the complex molecules of interest and the ICT processes of the excited molecules were verified. The nonlinear optical properties of the molecules were studied using a Z-scan technique. It is found that not only the structure of the molecules influences the nonlinear optical properties, but that also the solvent-solute interaction plays an important role.

Graphdiyne is a new carbon allotrope comprising sp- and sp2 -hybridized carbon atoms arranged in a 2D layered structure. In this contribution, 2D graphdiyne is demonstrated to exhibit a strong light-matter interaction with high stability to achieve a broadband Kerr nonlinear optical response, which is useful for nonreciprocal light propagation in passive photonic diodes. Furthermore, advantage of the unique Kerr nonlinearity of 2D graphdiyne is taken and a nonreciprocal light propagation device is proposed based on the novel similarity comparison method. Graphdiyne has demonstrated a large nonlinear refractive index in the order of ≈10-5 cm2 W-1 , comparing favorably to that of graphene. Based on the strong Kerr nonlinearity of 2D graphdiyne, a nonlinear photonic diode that breaks time-reversal symmetry is demonstrated to realize the unidirectional excitation of Kerr nonlinearity, which can be regarded as a significant demonstration of a graphdiyne-based prototypical application in nonlinear photonics and might suggest an important step toward versatile graphdiyne-based advanced passive photonics devices in the future.

We have designed and synthesized the original example of stable 3H-pyrrolizine fused diazaborepin using boron–amine (B–N) chemistry. 3H-Pyrrolizine fused ‘naked’ diazaborepin was achieved by organocatalyst (piperidinium acetate) in modest yield. The structure of diazaborepin was a twisted backbone in saddle shape with torsion angels of more than 20° from its crystal and theoretical data. It had a larger stokes shift (>70 nm) than classical BODIPYs and the type of solvent had an effect on their fluorescence property.

Four donor-π bridge-acceptor structured boron dipyrromethene type sensitizers bearing triarylamine donors with different rigidities were synthesized and applied in dye-sensitized solar cells. The influence of different triarylamine donors on the optical, electrochemical properties and photovoltaic performances of sensitizers was systematically investigated. It was shown that the photovoltaic performance of boron dipyrromethene type sensitizer-based cell increased with increasing the fluorescence quantum yield and fluorescence lifetime of the corresponding sensitizers, which are believed to be closely related to the rigidities of the donor groups in the molecule. The best performance was realized for the cell based on rigid 9-phenyl-carbazole-substituted boron dipyrromethene sensitizer ( ZH-b ) with a fluorescence quantum yield of 0.516 and a fluorescence lifetime of 4.02 ns, resulting in a short circuit photocurrent density of 14.10 mA/cm 2 and an overall conversion efficiency of 4.42%, which are fairly good results achieved for boron dipyrromethene type sensitizer-based solar cell.