Smart MOF-on-MOF Hydrogel as a Simple Rod-shaped Core for Visual Detection and Effective Removal of Pesticides.

The immoderate use of pesticides in the modern agricultural industry has led to the pollution of water resources and ultimately threatens the human body. Herein, two metal-organic frameworks (MOFs), namely {[Zn(tpt)2 ·2H2 O]}n (Zn1) and {[Zn2 (tpt)2 (bdc)]}n (Zn2), (Htpt = 5-[4(1H-1,2,4-triazol-1-yl)]phenyl-2H-tetrazole), respectively, are constructed as smart materials for visual and on-site detection of pesticides and their removal from water. The exposed nitrogen-rich sites and high chemical stability make Zn2 a self-assembly core to further fabricate MOF-on-MOF-sodium alginate (ZIF-8-on-Zn2@SA) composite by wrapping ZIF-8 on the outside surface. Inheriting the excellent fluorescent emission of Zn2, the rod-like ZIF-8-on-Zn2@SA module exhibits naked-eye detection of thiophanate-methyl (TM) in real fruits and vegetables with a broad linear range (10-100 × 10-6  m), a low limit of detection (LOD = 0.14 × 10-6  m), and satisfactory recoveries (98.30-102.70%). In addition, carbendazim (CBZ), the metabolite of TM after usage in crops, can be efficiently removed from water by the ZIF-8-on-Zn2@SA (qmax  = 161.8 mg g-1 ) with a high correlation coefficient (R2  > 0.99). Therefore, the portable ZIF-8-on-Zn2@SA sensing platform presents a promising candidate for monitoring and removal of pesticides, especially suitable for regions with serious pesticide environmental pollution.

Structural Design of Low Toxicity Metal-Organic Frameworks for Multifunction Detection of Organic and Inorganic Contaminants from Water.

Metal-organic frameworks (MOFs)-based sensors for monitoring toxic substances in wastewater have attracted great attention due to the efficient and reliable performance. Here, we has synthesized two novel zinc-based MOFs [Zn(ttb)2(H2O)2]n (Zn1-ttb) and {[Zn(ttb)2]·0.5CH3CN}n (Zn2-ttb) through changing the polarity of reaction solvents and finally obtained target 2D MOF material [Zn(ttb)(bdc)0.5]n(Zn3-ttb-bdc) by successfully introducing an ancillary ligand H2bdc (Httb = 1-(triazo-1-ly)-4-(tetrazol-5-ylmethyl)benzene, H2bdc = 1,4-benzenedicarboxylic acid). As-prepared Zn3-ttb-bdc exhibits high water and chemical stability as well as excellent fluorescence property. Due to the -COOH binding sites from H2bdc, Zn3-ttb-bdc shows high sensitivity and a rapid luminescent response to a representative organic micropollutant trinitrophenol (TNP) and inorganic pollutants (Fe3+ and Cr2O72-) in wastewater. The mechanisms of multifunctional detection abilities of Zn3-ttb-bdc toward different types of pollutants are further studied. This work presents the structural design in preparing MOF materials for multifunctional detection performance, thus opening new perspectives for emerging MOF-based sensors as environmental monitors.

Metal-Organic Complexes@Melamine Foam Template Strategy to Prepare Three-Dimensional Porous Carbon with Hollow Spheres Structures for Efficient Organic Vapor and Small Molecule Gas Adsorption.

Three-dimensional (3D) porous carbon materials have received substantial attention owing to their unique structural features. However, the synthesis of 3D porous carbon, especially 3D porous carbon with hollow spheres structures at the connection points, still pose challenges. Herein, we first develop a metal-organic complexes@melamine foam (MOC@MF) template strategy, by using hot-pressing and carbonization method to synthesize 3D porous carbon with hollow spheres structures (denoted as NOPCs). The formation mechanism of NOPCs can be attributed to the difference in Laplace pressure and surface energy gradient between the carbonized MOC and carbonized MF. These rare 3D porous carbons exhibit high BET surface area (2453.8 m2 g-1), N contents (10.5%), and O contents (16.3%). Moreover, NOPCs show significant amounts of toluene and methanol at room temperature, reaching as high as 1360 and 1140 mg g-1. The adsorption amounts of SO2 and CO2 for NOPCs are up to 93.1 and 445 mg g-1. Theoretical calculation indicates surfaces of porous carbon with N and O coexistence could strongly enhance adsorption with high adsorption energy of -65.83 kJ mol g-1.

Micromesoporous Nitrogen-Doped Carbon Materials Derived from Direct Carbonization of Metal-Organic Complexes for Efficient CO2 Adsorption and Separation.

Metal-organic complexes (MOCs) are considered as excellent precursors to prepare carbon materials, due to the fact that heteroatoms and functional groups can be naturally reserved in the resulting carbon materials through the carbonization. Herein, micromesoporous nitrogen-doped carbons MPNC-1 and MPNC-2 are successfully obtained by direct carbonization (800 °C, KOH activation) of metal-organic complexes DQA-1 and DQA-2. MPNC-1 and MPNC-2 exhibit high BET surface area (2368.9 and 2327.6 m2 g-1), pore volume (1.95 and 1.89 cm3 g-1), and N contents (17.2% and 12.3%). At 25 °C and 1 bar, MPNC-1 and MPNC-2 show high CO2 adsorption of 7.53 and 6.58 mmol g-1, the estimated CO2/N2 selectivity are 20.5 and 22.6, indicating excellent promise for practical CO2 adsorption and separation applications. Theoretical calculation indicates carbon surfaces with pyridinic-N, pyrrolic-N, and graphitic-N coexistence could strongly change the local electronic distribution and electrostatic surface potential, enhancing the CO2 adsorption with adsorption energy of -58.96 kJ mol g-1. Theoretical calculation also highlights that CO2 adsorption mechanism is electrostatic interaction with a large green isosurface between CO2 molecules and the carbon surface.

Lanthanide Coordination Polymer-Based Composite Films for Selective and Highly Sensitive Detection of Cr2O72- in Aqueous Media.

Due to the high carcinogenicity and bioaccumulation effects of dichromate ions in the human body, sensitive and rapid detection of Cr2O72- ions is necessary. Herein, two lanthanide coordination polymers based on a linear dicarboxylic acid ligand, named {Ln(cpon)(Hcpon)(H2O)3}n [Ln = Tb, Tbcpon; Eu, Eucpon; H2 cpon = 5-(4-carboxy-phenoxy)-nicotinic acid], have been successfully synthesized. These two isostructural compounds contain one-dimensional zigzag chains that consist of uncoordinated carboxyl groups and pyridine groups in the framework, and the one-dimensional chains can further form a three-dimensional supramolecular stacking structure by intermolecular interaction. Both Tbcpon and Eucpon show good luminescence performance and high stability. Tbcpon exhibits a good ability to sense Cr2O72- ions in aqueous solution. Moreover, the composite film material composed of Tbcpon and poly(methyl methacrylate) (PMMA) exhibits superior luminescence properties compared to those of pure Tbcpon. The Tbcpon-PMMA film exhibits an excellent ability to recognize Cr2O72- ions with high selectivity and a low detection limit of 5.6 ppb, which is much lower than the maximum contamination standard of 100 ppb in drinking water specified by the U.S. Environmental Protection Agency. Furthermore, the Tbcpon-PMMA film shows good recyclability for more than five cycles and anti-interference ability. After the introduction of the slightly soluble polymer poly(vinyl alcohol) (PVA), the Tbcpon-PVA composite film can effectively detect Cr2O72- ions in as little as 1 min. These composite films could be potentially used as test strips for trace detection and rapid detection of Cr2O72- ions in aqueous solution.

A Dual Associated-Functional Fluorescent Switch: From Alternate Detection Cycle for Fe(III) and pH to Molecular Logic Operations.

With the expansion and deepening of scientific research, dual-functional or multifunctional materials are urgently needed to replace those for single application. Herein, a fluorescence sensing system based on an In(III)-organic complex with in situ Lewis acid sites has been constructed, exhibiting high sensitivity for the detection of Fe(III) ions with a low detection limit of 3.95 µM and a short response time of within 10 s. It is noteworthy that the quenched fluorescence of the Fe(III)-incorporated sample could be reopened linearly with an increase of alkalinity, followed by the reactivation of its functionality to identify Fe(III) ions, forming an alternate detection cycle for Fe(III) and pH with off-on-off fluorescent switch characteristics. Considering its unique molecular recognition capability, an advanced three-input (Fe(III), EDTA, and OH-) and two-output (B440 and G489) Boolean logic operation comprising BUFF, NOT, OR, and AND logic gates was integrated, possessing potential applications in intelligent multianalyte sensing systems.

Synthesis of an Efficient Counter Electrode Material for Dye-Sensitized Solar Cells by Pyrolysis of Melamine and Graphene Oxide.

An efficient counter electrode material for dye sensitized solar cells (DSSCs) was synthesized by pyrolysis of melamine and graphene oxide. The synthesized samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy and scanning electrode microscopy, which show that nitrogen doped reduced graphene oxide (NRGO) was obtained by this synthesis method. In the synthesized NRGO, graphitic structure was kept and the nitrogen was existence as pyrrolic, pyridinic, graphitic, and oxidized nitrogen species in the samples. After deposited as counter electrode films for DSSCs, it shows lower charge-transfer resistance at the electrode/electrolyte interface and higher electrocatalytic activity towards reduction of triiodide (I-3) than that of reduced graphene oxide (RGO) prepared also by this method without adding melamine. Consequently, the DSSCs based on NRGO counter electrodes achieve an energy conversion efficiency of 4.60%, which is higher than that of RGO counter electrode (2.35%). Although the photovoltaic performance of NRGO counter electrode was lower than that of Pt counter electrode (5.70%), it is still a promising counter electrode to replace noble metal Pt due to its low cost and simple synthesis process.

Self-Assembly of Hybrid Oxidant POM@Cu-BTC for Enhanced Efficiency and Long-Term Stability of Perovskite Solar Cells.

The controllable oxidation of spiro-OMeTAD and improving the stability of hole-transport materials (HTMs) layer are crucial for good performance and stability of perovskite solar cells (PSCs). Herein, we report an efficient hybrid polyoxometalate@metal-organic framework (POM@MOF) material, [Cu2 (BTC)4/3 (H2 O)2 ]6 [H3 PMo12 O40 ]2 or POM@Cu-BTC, for the oxidation of spiro-OMeTAD with Li-TFSI and TBP. When POM@Cu-BTC is introduced to the HTM layer as a dopant, the PSCs achieve a superior fill factor of 0.80 and enhanced power conversion efficiency 21.44 %, as well as improved long-term stability in an ambient atmosphere without encapsulation. The enhanced performance is attributed to the oxidation activity of POM anions and solid-state nanoparticles. Therefore, this research presents a facile way by using hybrid porous materials to accelerate oxidation of spiro-OMeTAD, further improving the efficiency and stability of PSCs.

Unusually Flexible Indium(III) Metal-Organic Polyhedra Materials for Detecting Trace Amounts of Water in Organic Solvents and High Proton Conductivity.

Humidity-induced single-crystal transformation was observed in the indium metal-organic polyhedra [In2(TCPB)2]·2H2O (In1), where H3TCPB is 1,3,5-tri(4-carboxyphenoxy)benzene. When the humidity is above 58% relative humidity (RH) at room temperature, the neutral compound In1 could be successfully converted into the positively charged compound In1-H along with the color change from yellow to deep red, which also undergoes a reversible transformation into In1 driven by thermal dehydration. Notably, the color of In1 takes only 5 min to change under 58% RH at room temperature, which is much quicker than common desiccant bluestone. As the water content is increased from 0.0% to 0.2% in acetonitrile solvent, compound In1 exhibits rapid detection of trace amounts of water through turn-off luminescence sensing mechanism with a low detection limit of 2.95 × 10-4%. Because of the formation of extensive hydrogen-bonding network between the metal-organic polyhedra (MOPs) and surrounding guest OH- ions, compound In1-H, along with isostructural Ga1-H, displays excellent proton conductivity up to 2.84 × 10-4 and 2.26 × 10-4 S cm-1 at 298 K and 98% RH, respectively. Furthermore, the activation energies are found to be 0.28 eV for In1-H and 0.34 eV for Ga1-H. This method of incorporation of OH- ions to obtain high proton conductivity MOPs with low activation energy demonstrates the advantage of OH- ion conduction in the solid-state materials.

Research on the Mechanism of Aggregation-Induced Emission through Supramolecular Metal-Organic Frameworks with Mechanoluminescent Properties and Application in Press-Jet Printing.

This study investigates the mechanism of AIE in the solid state through supramolecular metal-organic frameworks and mechanoluminescent materials for the first time. Herein, four novel differently substituted Schiff base building blocks, SB1-SB4, exhibit typical AIE properties with various fluorescence emissions from yellow to green. SB1-SB4 are linked through C-H···O hydrogen bonding interactions to construct supramolecular metal-organic frameworks (SMOFs): namely, SMOFSB1-SMOFSB4. Particularly, among these SMOFs, SMOFSB3 is observed to have micropores in the 3D supramolecular structure and exhibits mechanoluminescent properties (grinding). An emission turn-on mechanism occurs with destruction of micropores by grinding and blockage of intramolecular rotations of the methyl and acetonitrile in the micropores, resulting in emission turn-on in SMOFSB3. Single-crystal X-ray structures, powder X-ray diffraction, emission spectra at room temperature, temperature-dependent emission spectra, DFT calculations, and a charge separation hypothesis well demonstrate the emission turn-on mechanism, which is consistent with the mechanism of AIE. More importantly, the molecules demonstrated potential application for press-jet printing.

HONH3Cl optimized CH3NH3PbI3 films for improving performance of planar heterojunction perovskite solar cells via a one-step route.

Planar heterojunction perovskite solar cells (PHJ-PSCs) constructed with one-step precursor solution spin-coating deposition (OPSSD) usually give an extremely low performance mainly due to the poor morphology and low crystallinity of the perovskite films. In this work, by incorporating a suitable HONH3Cl additive in the perovskite precursor solution, a high quality perovskite film with improved morphology and crystallinity was obtained. The UV-vis measurement of the CH3NH3I solutions without and with HONH3Cl demonstrates that the improved quality of the perovskite film can be easily attributed to a combined effect of N2, I2, H2O and CH3NH3Cl originating from the oxidation of CH3NH3I triggered by the HONH3Cl additive, which can manipulate the crystallization process of the perovskite. Accordingly, the improved performance for the HONH3Cl-induced PHJ-PSCs can also be demonstrated. At the optimized molar ratio of 1 : 1 : 0.1 for PbI2 : CH3NH3I : HONH3Cl, the PHJ-PSCs exhibit an average power conversion efficiency (PCE) of 10.61 ± 0.51%, which is much higher than that of pristine 1 : 1 : 0 based cells without additive (7.21 ± 0.61%), and the best performing HONH3Cl-induced device can yield a PCE as high as 11.12% with a Jsc of 18.42 mA cm-2, Voc of 0.95 V and FF of 0.63. Introducing suitable HONH3Cl as an additive into the perovskite precursor solution is really an effective route to enhance the performance of the PHJ-PSCs via OPSSD.

[Study on the Structure and Photoluminescent Properties of Mono-Zn(â ¡) and Di-Cu(â ) Complexes Constructed from Nitrogen Heterocyclic Ring Ligand].

The mononuclear Zn(Ⅱ) complex [Zn(2,6-PDA)(phen)H2O]·H2O (1) and binuclear Cu(Ⅰ) complex{[Cu(µ-Ⅰ)(phen)H2O]·H2O}2 (2) (2,6-H2PDA=2,6- pyridinedicarboxylic acid，phen=1,10- phenanthroline monohydrate) have been prepared with hydro-thermal synthesis method. These complexes have been characterized with single-crystal X-ray, elemental analysis, and IR spectroscopy. The fluorescence spectra of 1 and 2 are studied in solid-state and dimethyl sulfoxide (DMSO) solution. The maximum absorption peak of 1 and 2 are at 253 nm and 242 nm respectively, which are red shift to that of the phen ligand with inceased intensity. It may be assigned to the intraligand π→π* transition of the phen ligand that is modified by the Zn(Ⅱ) or Cu(Ⅰ) ions. On the basis of the coordination, the absorption of organic ligands in the ultraviolet region is increased, which is better for the energy absorption of the ligand. 1 and 2 all showed blue light emission. The emission peak of 1 and 2 have experienced a red shift (ca. 55 and 23 nm) in the solid state (λem = 407, 434, 467 nm for 1, 442, 469, 501 nm for 2) compared to in DMSO solution (λem = 361, 379, 392 nm for 1, 422, 443, 461 nm for 2). The red shift phenomenon can be attributed to the π-stacking of the aromatic rings and other intermolecular Interactions in these molecules in the solid state. Especially, the strong Cu(Ⅰ)…Cu(Ⅰ) interaction of 2 can decrease the HOMO­LUMO energy gap with the red-shifted emission wavelength.

A Series of Lanthanide Metal-Organic Frameworks with Interesting Adjustable Photoluminescence Constructed by Helical Chains.

Based on the isonicotinic acid (HIN=pyridine-4-carboxylic acid), seven lanthanide metal-organic frameworks (MOFs) with the formula [Ln(IN)2 L] (Ln=Eu (1), Tb (2), Er (3), Dy (4), Ho (5), Gd (6), La (7), L=OCH2 CH2 OH) have been synthesized by mixing Ln2 O3 with HIN under solvothermal conditions, and characterized by single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, and fluorescence spectroscopy. Crystal structural analysis shows that compounds 1-6 are isostructural, crystallize in a chiral space group P21 21 21 , whereas compound 7 crystallizes in space group C2/c. Nevertheless, they all consist of new intertwined chains. Simultaneously, on the basis of the above-mentioned compounds, we have realized a rational design strategy to form the doped Ln MOFs [(Eux Tb1-x )(IN)2 L] (x=0.35 (8), x=0.19 (9), x=0.06 (10)) by utilizing Tb(III) as the second "rare-earth metal". Interestingly, the photoluminescence of [(Eux Tb1-x )(IN)2 L] are not only adjustable by the ratios of Eu/Tb, but also temperature or excitation wavelength.

Tunable Luminescence and Application in Dye-Sensitized Solar Cells of Zn(II)/Hg(II) Complexes: Methyl Substitution-Induced Supramolecular Structures Based on (E)-N-(6-Methoxypyridin-2-ylmethylene)arylamine Derivatives.

Using Schiff-base ligands (E)-N-(6-methoxypyridin-2-yl)(CH═NAr) (where Ar = C6H5, L1; 2-MeC6H4, L2; 2,4,6-Me3C6H2, L3), six Zn(II)/Hg(II) complexes, namely, [ZnL1Cl2] (Zn1), [HgL1Cl2] (Hg1), [ZnL2Cl2] (Zn2), [HgL2Cl2] (Hg2), [ZnL3Cl2] (Zn3), and [HgL3Cl2] (Hg3) have been synthesized under solvothermal conditions. The structures of six complexes have been established by X-ray single-crystal analysis and further physically characterized by EA, FT-IR, (1)H NMR, and ESI-MS. The crystal structures of these complexes indicate that noncovalent interactions, such as hydrogen bonds, C-H···Cl, and π···π stacking, play essential roles in constructing the resulting supramolecular structures (1D for Hg3; 2D for Zn2, Hg2; 3D for Zn1, Hg1, and Zn3). Upon irradiation with UV light, the emission of complexes Zn1-Zn3 and Hg1-Hg3 could be finely tuned from green (480-540 nm) in the solid state to blue (402-425 nm) in acetonitrile solution. It showed that the ligand and metal cation can influence the structures and luminescence properties of complexes such as emission intensities and maximum wavelengths. Since these ligands and complexes could compensate for the absorption of N719 in the low-wavelength region of the visible spectrum and reduce charge recombination of the injected electron, the ligands L1-L3 and complexes Zn3/Hg3 were employed to prepare cosensitized dye-sensitized solar cells devices for investigating the influences of the electron-donating group and coordination on the DSSCs performance. Compared to DSSCs only being sensitized by N719, these prepared ligands and complexes chosen to cosensitize N719 in solar cell do enhanced its performance by 11-41%. In particular, a DSSC using L3 as cosensitizer displays better photovoltaic performance with a short circuit current density of 18.18 mA cm(-2), corresponding to a conversion efficiency of 7.25%. It is much higher than that for DSSCs only sensitized by N719 (5.14%).

Efficiency of ruthenium dye sensitized solar cells enhanced by 2,6-bis[1-(phenylimino)ethyl]pyridine as a co-sensitizer containing methyl substituents on its phenyl rings.

2,6-Bis[1-(phenylimino)ethyl]pyridine (M0) and its derivatives containing methyl groups on their phenyl rings (M1o, M1p and M2) are employed as co-sensitizers in dye-sensitized solar cells (DSSCs). The prepared co-sensitizers could alleviate the aggregation of ruthenium dye N719 on the TiO2 film, enhance the spectral responses of the co-sensitized TiO2 film in the region from 400 to 750 nm, suppress the electron recombination, prolong the electron lifetime and decrease the total resistance of DSSCs. The number and position of the methyl groups are two key factors that play important roles in the performances of DSSCs. The optimized cell device co-sensitized by the M1p/N719 dye gives a short circuit current density of 16.48 mA cm(-2), an open circuit voltage of 0.72 V and a fill factor of 0.62 corresponding to an overall conversion efficiency of 7.32% under standard global AM 1.5 solar irradiation, which is 35% higher than that of a device solely sensitized by N719 under the same conditions.

A detailed study on the working mechanism of a heteropoly acid modified TiO2 photoanode for efficient dye-sensitized solar cells.

A novel heteropolyacid (HPA) K6SiW11O39Ni(H2O)·xH2O (SiW11Ni) modified TiO2 has been successfully synthesized and introduced into the photoanode of dye-sensitized solar cells (DSSCs). The performance of the cell with the HPA-modified photoanode (SiW11Ni/TiO2), mixed with P25 powder in the ratio of 2 : 8, is better than the cell with a pristine P25 photoanode. An increase of 31% in the photocurrent and 22% improvement in the conversion efficiency are obtained. The effect of the heteropolyacid was well studied by UV-vis spectroscopy, spectro-electrochemical spectroscopy, dark current, intensity-modulated photocurrent spectroscopy and intensity-modulated photovoltage spectroscopy, open-circuit voltage decay and electrochemical impedance spectroscopy. The results show that the interfacial layer modified by SiW11Ni can enhance the injection and transport of electrons, and then retard the recombination of electrons, which results in a longer electron lifetime. What's more, the introduction of SiW11Ni can simultaneously broaden the absorption in the visible region, eventually leading to an efficient increase in energy conversion efficiency.

[A purple-emitting luminescence complex [Cd(bpdc)(phen)2(H2O)] . 6H2O: synthesis, structure and spectral properties].

A supramolecular Cd(II) complex[Cd(bpdc) (phen)2 (H2O)] . 6H20 (1) was synthesized with 2, 4'-biphenyldicarboxylic acid (H2bpdc) and 1, 10-phenanthroline (phen) under hydrothermal conditions and characterized by single-crystal X-ray diffraction elemental analysis, and IR spectrum. Single-crystal X-ray analysis reveals complex 1 crystalizes in the triclinic P 1 space group, the metal center Cd(II) ion is six-coordinated and exhibits a distorted octahedron geometry arrangement. 3D supramolecular structure could be formed taking into account two kinds of hydrogen bonds and π--π interactions. At the same time, we discussed the luminescent properties of complex 1 in the solid-state as well as in the solvents at different temperatures. When excited at 350 nm, in the solid state at 298 K, 1 has purple luminescence with emission band at 390 nm; in the solid state at 77 K, 1 displays two emission bands at 380 and 520 nm. Because the vibration structure is more defined at low temperature, at 298 K, 1 also has purple luminescence in DMSO and CH3OH solutions with emission bands at 380 and 375 nm, which are blue-shifted compared with solid-state maximum emission band. These all can be attribute to the π*-->π transition based on the coordinate ligands. The fluorescence decay curves of complex 1 indicate that the processes of decay consist of two components. At 298 K, the lifetime of 1 is longer in DMSO solution (τ1 =1. 73 µs and τ2 =14. 07 µs) than that in CH3OH solution (τ1 =1. 21 µs and τ2 = 12. 44 µs). Moreover, the-lifetime of 1 is longer at 77 K (τ1 =1. 96 µs and τ2= 16. 11 µs) than that at 298 K in the solid state (τ1= 1. 20 µs and τ2 =11. 34 µs). The results might be caused by the increase in radiative rate and decrease in non-radiative rate at low temperature.

Enhanced near-infrared to visible upconversion nanoparticles of Ho³âº-Yb³âº-F⁻ tri-doped TiO2 and its application in dye-sensitized solar cells with 37% improvement in power conversion efficiency.

New near-infrared (NIR)-to-green upconversion nanoparticles of Ho(3+)-Yb(3+)-F(-) tridoped TiO2 (UC-F-TiO2) were designed and fabricated via the hydrosol-hydrothermal method. Under 980 nm NIR excitation, UC-F-TiO2 emit strong green upconversion fluorescence with three emission bands at 543, 644, and 751 nm and convert the NIR light in situ to the dye-sensitive visible light that could effectively reduce the distance between upconversion materials and sensitizers; thus, they minimize the loss of the converted light. Our results show that this UC-F-TiO2 offers excellent opportunities for the other types of solar cells applications, such as organic solar cells, c-Si solar cells, multijunction solar cells, and so on. When integrating the UC-F-TiO2 into dye-sensitized solar cells (DSSCs), superior total energy conversion efficiency was achieved. Under AM1.5G light, open-circuit voltage reached 0.77 ± 0.01 V, short-circuit current density reached 21.00 ± 0.69 mA cm(-2), which resulted in an impressive overall energy conversion efficiency of 9.91 ± 0.30%, a 37% enhancement compared to DSSCs with pristine TiO2 photoanode.

Clinical Voice Outcomes for Two Voice Rest Protocols after Phonomicrosurgery.

OBJECTIVES: Voice rest is commonly recommended for patients with benign vocal fold lesions (BVFLs) after phonomicrosurgery. The study compares the clinical voice outcomes of two protocols, 7-day complete voice rest (CVR) and 3-day CVR followed by 4-day relative voice rest (CVR + RVR), for patients with BVFLs after phonomicrosurgery. STUDY DESIGN: Prospective, randomized controlled trial. METHOD: Patients with BVFLs undergoing phonomicrosurgery were recruited prospectively and randomly assigned to either protocol. Outcomes were assessed on objective measures of acoustics (fundamental frequency, frequency range, mean intensity, cepstral peak analysis) and aerodynamics (vital capacity, airflow rate, subglottal pressure, phonation threshold pressure), as well as subjective measures, both provider-reported through the Consensus Auditory-Perceptual Evaluation of Voice (CAPE-V), and patient-reported through the Voice Handicap Index (VHI). Clinical measures were collected at three-time points: preoperatively, 1-week postoperatively (on voice rest), and 1-month postoperatively. In addition, adherence was estimated using a vocal dosimeter. RESULTS: Twenty-five patients were recruited and randomized to 7-day CVR (n = 13) and CVR + RVR regimen (n = 12). Statistically significant changes were found within both groups for subglottal pressure (p = 0.03) and VHI score (p < 0.001) comparing pre-operative baseline to 1-month postoperative follow-up. There were no statistically significant differences between the groups. Regardless of group assignment, a significant decrease in overall severity ratings for the CAPE-V was found by comparing the preoperative scores to postoperative scores at 1-week (p < 0.001) and 1-month (p < 0.001). CONCLUSION: Both groups improved their overall voice quality comparably 1 month after undergoing phonomicrosurgery as measured by objective and subjective parameters. LEVELS OF EVIDENCE: 2. Laryngoscope, 134:2812-2818, 2024.

[Synthesis, crystal structure and spectral properties study of a 3D netlike coordination polymer [Zn(HBIDC) x H2O]n].

The 3D netlike coordination polymer of Zn II with benzimidazole-5,6-dicarboxylic acid (H3BIDC), [Zn(HBIDC) x H2O]n was synthesized by the hydrothermal method through self-assembling. The crystal structure of complex 1 was characterized by single-crystal X-ray diffraction, elemental analysis and IR spectra, and we also studied the fluorescence properties of complex 1 in DMSO and in the solid state with UV-Vis absorption spectra, fluorescence spectra and fluorescence lifetime. Complex 1 has blue luminescence in solutions of DMSO with emission band at 481 nm; and has blue luminescence in the solid state at room temperature with a strong emission band at 493 nm, and these all can be attributed to the pi* --> pi transition based on the benzimidazole-5,6-dicarboxy acid. The experimental results indicate that complex 1 displays higher fluorescence quantum efficiency and can be used as a potential blue luminescence material.