Hierarchical chiral MOFs with the induced chirality of AIE ligands exhibiting non-reciprocal CPL.

Two pairs of chiral MOFs with hierarchical chiral structures were constructed through assembly of achiral AIE-type multidentate linkers and chiral camphoric acid. Non-reciprocal circularly polarized luminescence (CPL) can be observed on the macroscopic due to the coexistence of optical anisotropic and chiroptical nature. This study provides a new perspective to recognize and construct chiral crystalline materials.

Transition-Metal Porphyrin-Based MOFs In Situ-Derived Hybrid Catalysts for Electrocatalytic CO2 Reduction.

Excellent electrocatalytic CO2 reduction reaction activity has been demonstrated by transition metals and nitrogen-codoped carbon (M-N-C) catalysts, especially for transition-metal porphyrin (MTPP)-based catalysts. In this work, we propose to use one-step low-temperature pyrolysis of the isostructural MTPP-based metal-organic frameworks (MOFs) and electrochemical in situ reduction strategies to obtain a series of hybrid catalysts of Co nanoparticles (Co NPs) and MTPP, named Co NPs/MTPP (M = Fe, Co, and Ni). The in situ introduction of Co NPs can efficiently enhance the electrocatalytic ability of MTPP (M = Fe, Co, and Ni) to convert CO2 to CO, particularly for FeTPP. Co NPs/FeTPP endowed a high CO faradaic efficiency (FECOmax = 95.5%) in the H cell, and the FECO > 90.0% is in the broad potential range of -0.72 to -1.22 VRHE. In addition, the Co NPs/FeTPP achieved 145.4 mA cm-2 at a lower potential of -0.70 VRHE with an FECO of 94.7%, and the CO partial currents increased quickly to reach 202.2 mA cm-2 at -0.80 VRHE with an FECO of 91.6% in the flow cell. It is confirmed that Co NPs are necessary for hybrid catalysts to get superior electrocatalytic activity; Co NPs also can accelerate H2O dissociation and boost the proton supply capacity to hasten the proton-coupled electron-transfer process, effectively adjusting the adsorption strength of the reaction intermediates.

The Incidences and Related CT Features of Vascular Lake Phenomenon on Angiography Before Chemoembolization.

PURPOSE: To elucidate incidence rates of vascular lake phenomenon (VLP) in hepatocellular carcinoma (HCC), intrahepatic cholangiocarcinoma (ICC), hepatic metastasis (HMT) on transarterial angiography before chemoembolization, and to identity CT features predictive for it. MATERIALS AND METHODS: A comprehensive evaluation involved 665 subjects for incidence analysis, comprising 527 of HCC, 33 of ICC and 105 of HMT. VLP was characterized as intratumoral contrast material pool persisting late into venous phase. Incidences were cataloged on both super-selective and common hepatic artery angiography. For CT features analysis, a subset of 182 cases were analyzed. Enhancement ratio served as an index for comparative analysis of nodule enhancement degrees. RESULTS: In HCC, incidence of VLP ascertained via super-selective angiography was 13.5%, whereas it as 7.8% on common hepatic artery angiography. Remarkably, no incidences of VLP were recorded in either ICC or HMT cases. On pre-interventional CT, the prevalence of pseudocapsule was statistically greater in VLP group than Non-VLP group (66.6% vs. 37.6%, P = 0.015). The Houndsfield units (HU) of tumors in plain scan (P = 0.007), arterial phase (P = 0.001), venous phase (P = 0.041), arterial phase enhancement ratio (P < 0.001) were statistically higher in VLP group compared to Non-VLP group. Arterial phase enhancement ratio (P = 0.025), presence of pseudocapsule (P = 0.001), HU of tumor in plain scan (P = 0.035) serve as independent risk factors for VLP manifestation. CONCLUSION: VLP is a distinct angiography phenomenon uniquely associated with HCC. High arterial phase enhancement ratio, presence of pseudocapsule, high HU of tumor in plain scan are independent risk factors for VLP.

Ultrafast Response in Nonenzymatic Electrochemical Glucose Sensing with Ni(II)-MOFs by Dimensional Manipulation.

Metal-organic frameworks (MOFs) are emerging as promising candidates for electrochemical glucose sensing owing to their ordered channels, tunable chemistry, and atom-precision metal sites. Herein, the efficient nonenzymatic electrochemical glucose sensing is achieved by taking advantage of Ni(II)-based metal-organic frameworks (Ni(II)-MOFs) and acquiring the ever-reported fastest response time. Three Ni(II)-MOFs ({[Ni6L2(H2O)26]4H2O}n (CTGU-33), {Ni(bib)1/2(H2L)1/2(H2O)3}n (CTGU-34), {Ni(phen)(H2L)1/2(H2O)2}n (CTGU-35)) have been synthesized for the first time, which use benzene-1,2,3,4,5,6-hexacarboxylic acid (H6L) as an organic ligand and introduce 1,4-bis(1-imidazoly)benzene (bib) or 1,10-phenanthroline (phen) as spatially auxiliary ligands. Bib and phen convert the coordination mode of CTGU-33, affording structural dimensions from 2D of CTGU-33 to 3D of CTGU-34 or 1D of CTGU-35. By tuning the dimension of the skeleton, CTGU-34 with 3D interconnected channels exhibits an ultrafast response of less than 0.4 s, which is superior to the existing nonenzymatic electrochemical sensors. Additionally, a low detection limit of 0.12 µM (S/N = 3) and a high sensitivity of 1705 µA mM-1 cm-2 are simultaneously achieved. CTGU-34 further showcases desirable anti-interference and cycling stability, which demonstrates a promising application prospect in the real-time detection of glucose.

Seaweed-like phosphates/MOF heterostructures as a synergistic electrocatalyst for alcohol oxidation.

A series of seaweed-like heterogeneous Co3(PO4)2/Ni3(PO4)2/MOF-74-x electrocatalysts were synthesized via a hydrothermal method. The optimal composite exhibits excellent catalytic performance toward methanol/ethanol oxidation reactions (MOR/EOR) with peak current densities reaching 27.5 and 32.6 mA cm-2, respectively. This work heralds the advent of more efficient heterogeneous electrocatalysts for DAFCs and other energy conversion systems.

Nonenzymatic Electrochemical Sensing Platform Based on 2D Isomorphic Co/Ni-Metal-Organic Frameworks for Glucose Detection.

Two-dimensional metal-organic framework (MOF) crystalline materials possess promising potential in the electrochemical sensing process owing to their tunable structures, high specific surface area, and abundant metal active sites; however, developing MOF-based nonenzymatic glucose (Glu) sensors which combine electrochemical activity and environmental stability remains a challenge. Herein, utilizing the tripodic nitrogen-bridged 1,3,5-tris(1-imidazolyl) benzene (TIB) linker, Co2+ and Ni2+, two 2D isomorphic crystalline materials, including Co/Ni-MOF {[Co (TIB)]·2BF4} (CTGU-31) and {[Ni(TIB)]·2NO3} (CTGU-32), with a binodal (3, 6)-connected kgd topological net were firstly synthesized and fabricated with conducting acetylene black (AB). When modified on a glassy carbon electrode, the optimized AB/CTGU-32 (1:1) electrocatalyst demonstrated a higher sensitivity of 2.198 µA µM-1 cm-2, a wider linear range from 10 to 4000 µM, and a lower detection limit (LOD) value (0.09 µM, S/N = 3) compared to previously MOF-based Glu sensors. Moreover, AB/CTGU-32 (1:1) exhibited desirable stability for at least 2000 s during the electrochemical process. The work indicates that MOF-based electrocatalysts are a promising candidate for monitoring Glu and demonstrate their potential for preliminary screening for diabetes.

Ar plasma assists in enhanced oxygen evolution kinetics of MOG-derived multicomponent transition metal sulfides.

Transition metal sulfides are low-cost oxygen evolution reaction (OER) electrocatalysts that can potentially substitute noble metal catalysts. However, the adsorption process of their OER is impeded by their intrinsic poor catalytic activity. Constructing heterojunction and vacancy defects in transition metal sulfides is an efficient method to promote the process of oxygen evolution. Herein, a facile approach based on in situ sulfurization of metal-organic gels (MOGs) and a short-time plasma treatment was developed to fabricate vacancy-modified polymetallic sulfides heterojunction. The synergistic effect of the multi-component heterojunction and sulfur vacancy contributed greatly to improving the electron migration efficiency and OER ability of the electrocatalyst. As a result, the optimum oxygen evolution activity was achieved with appropriate surface vacancy concentrations by regulating the plasma radio frequency powers. The plasma-treated catalyst under 400 W showed the best OER performance (lower overpotential of 235 mV in 1 M KOH solution with the Tafel slope of 31 mV dec-1) and good durability over 11 h of chronopotentiometry testing. This work sheds new light on constructing multimetal-based heterojunction electrocatalysts with rich vacancy defects for oxygen evolution reactions.

Prognostic comparison of active surveillance and adjuvant chemotherapy in the treatment of patients with stage Ⅰ ovarian immature teratoma after fertility-sparing surgery / 中华妇产科杂志

Objective: To compare the survival outcomes between surveillance and adjuvant chemotherapy in patients with stage Ⅰ ovarian immature teratoma (IMT) underwent fertility-sparing surgery. Methods: Clinical and pathological records of patients with stage Ⅰ ovarian IMT between Jan. 2011 to Feb. 2023 were collected from Peking Union Medical College Hospital, except stage Ⅰa grade 1. The consultation of risks and benefits regarding adjuvant chemotherapy was conducted by gynecologic oncologists. A shared decision about surveillance or chemotherapy was made by physician and patients or their guardians. Patients who finally decided to undergo surveillance were included in the surveillance group (n=40), the others were included in the adjuvant chemotherapy group (n=63). Clinical characteristics, treatment and survival outcomes were analyzed and compared between two groups. Results: A total of 103 patients were included. The median age of initial diagnosis was 20 years old (range: 3-39 years old), and the median follow-up time was 31 months (range: 1-254 months). The age, International Federation of Gynecology and Obstetrics (FIGO) stage, pathological grade, surgical method, and preoperative and postoperative alpha-fetoprotein levels in the surveillance group and the adjuvant chemotherapy group were similar (all P>0.05). The surgical approach and maximum tumor diameter between two groups were significantly different (all P<0.05). Forty patients of the surveillance group were identified, only one patient with stage Ⅰa grade 2 IMT who underwent cystectomy had malignant recurrence on the same ovary. Another 63 patients received adjuvant chemotherapy after surgery, five patients had malignant recurrence, and two of them died of disease progression after relapsed. There were no significant differences in disease-free survival (DFS;20 vs 36 months) and overall survival (OS; 23 vs 39 months) between the surveillance group and the adjuvant chemotherapy group (follow-up time censored at 72 months; DFS: P=0.325, OS: P=0.278). Conclusions: There are no differences in survival outcomes between patients with stage Ⅰ ovarian IMT underwent adjuvant chemotherapy or not. Active surveillance might be safe and preferable in stage Ⅰ IMT patients underwent complete resection of tumor.

Value of postoperative radiotherapy and analysis of prognostic factors in early-stage neuroendocrine carcinoma of cervix / 中华妇产科杂志

Objective: To evaluate the effect of postoperative radiotherapy and high-risk pathological factors on the prognosis of early-stage neuroendocrine carcinoma of cervix (NECC). Methods: A single-center retrospective cohort study of early-stage NECC in Peking Union Medical College Hospital from January 2011 to April 2022 were enrolled. The patients were treated with radical hysterectomy±adjuvant treatment. They were divided into postoperative non-radiation group and postoperative radiation group. The possible postoperative recurrence risk factors identified by univariate analysis were assessed using multivariate logistic regression. The Kaplan-Meier method was used to analyze the progression free survival (PFS), overall survival (OS), recurrence rate, and mortality rate. Results: (1) Sixty-two cases were included in the study, including 33 cases in postoperative non-radiation group and 29 cases in postoperative radiation group. (2) The median follow-up time was 37 months (ranged 12-116 months), with 23 cases (37%) experienced recurrences. There were 7 cases (11%) pelvic recurrences and 20 cases (32%) distant recurrences, in which including 4 cases (6%) both pelvic and distant recurrences. Compared with postoperative non-radiation group, the postoperative radiation group had a lower pelvic recurrence rate (18% vs 3%; P=0.074) but without statistic difference, a slightly elevated distant recurrence rate (24% vs 41%; P=0.150) and overall recurrence rate (33% vs 41%; P=0.513) without statistically significances. Univariate analysis showed that lymph-vascular space invasion and the depth of cervical stromal invasion≥1/2 were risk factors for postoperative recurrence (all P<0.05). Multivariate analysis showed lymph-vascular space invasion was an independent predictor for postoperative recurrence (OR=23.03, 95%CI: 3.55-149.39, P=0.001). (3) During the follow-up period, 18 cases (29%, 18/62) died with tumor, with 10 cases (30%, 10/33) in postoperative non-radiation group and 8 cases (28%, 8/29) in postoperative radiation group, without significant difference (P=0.814). The postoperative 3-year and 5-year survival rate was 79.2%, 60.8%. The depth of cervical stromal invasion≥1/2 was more common in postoperative radiation group (27% vs 64%; P=0.011), and postoperative radiation in such patients showed an extended trend in PFS (32.3 vs 53.9 months) and OS (39.4 vs 73.4 months) but without statistic differences (P=0.704, P=0.371). Compared with postoperative non-radiation group, the postoperative radiation did not improve PFS (54.5 vs 37.3 months; P=0.860) and OS (56.2 vs 62.4 months; P=0.550) in patients with lymph-vascular space invasion. Conclusions: Postoperative radiation in early-stage NECC patients has a trend to reduce pelvic recurrence but not appear to decrease distant recurrence and overall recurrence, and has not improved mortality. For patients with the depth of cervical stromal invasion≥1/2, postoperative radiation has a trend of prolonging OS and PFS but without statistic difference. Lymph-vascular space invasion is an independent predictor for postoperative recurrence, but postoperative radiation in such patients does not seem to have any survival benefits.

Multicolor-tunable room-temperature afterglow and circularly polarized luminescence in chirality-induced coordination assemblies.

Dynamic long-lived multicolor room temperature afterglow and circularly polarized luminescence (CPL) are promising for optoelectronic applications, but integration of these functions into a single-phase chiroptical material is still a difficult and meaningful challenge. Here, a nitrogen-doped benzimidazole molecule 1H-1,2,3-triazolopyridine (Trzpy) showing pure organic room-temperature phosphorescence (RTP) acted as a linker, and then, we propose a chirality-induced coordination assembly strategy to prepare homochiral crystal materials. Two homochiral coordination polymers DCF-10 and LCF-10 not only exhibit multicolor-tunable RTP, the color changed from green to orange under various excitation wavelengths, but also show remarkable excitation-dependent circularly polarized luminescence (CPL), and the dissymmetry factors of CPL in DCF-10 and LCF-10 are 1.8 × 10-3 and 2.4 × 10-3, respectively. Experimental and theoretical studies demonstrated that molecular atmospheres with different aggregation degrees give rise to multiple emission centers for the generation of multicolor-tunable emission. The multicolor-tunable photophysical properties endowed LCF-10 with a huge advantage for multi-level anti-counterfeiting. This work opens up new perspectives for the development and application of color-tunable RTP and CPL.

Facile in Situ Transformation of NiOOH into MOF-74(Ni)/NiO OH Heterogeneous Composite for Enchancing Electrocatalytic Methanol Oxidation.

A new MOF-74(Ni)/NiOOH heterogeneous composite was synthesized via NiOOH microsphere precursor. The electrocatalytic methanol oxidation reactions' (MOR) performance was assessed. The as-prepared MOF-74(Ni)/NiOOH exhibited excellent activity with high peak current density (27.62 mA·cm-2) and high mass activity (243.8 mA·mg-1). The enhanced activity could be a result of the synergistic effect of the MOF-74(Ni)/NiOOH heterocomposite providing more exposed active sites, a beneficial diffusion path between the catalyst surface and electrolyte, and improved conductivity, favorable for improving MOR performance.

Thermal treatment for promoting interfacial interaction in Co-BDC/Ti3C2Tx hybrid nanosheets for hybrid supercapacitors.

The design and synthesis of high-performance metal-organic frameworks (MOFs)-based electrodes are important for hybrid supercapacitors (HSC). Herein, enhanced interfacial interaction in Co-BDC/Ti3C2Tx (denoted as CoTC) hybrid nanosheets is achieved through thermal treatment, giving remarkably improved capacity performance compared with CoTC. The low temperature annealing treatment enables modulation of the bridging bonds content of CoTC and thus regulates the interfacial coupling effect between Co-BDC and Ti3C2Tx. Moreover, both the detailed XPS and XANES analysis reveal that the strong interfacial interactions between the two components promote a partial electron transfer from Ti3C2Tx to Co-BDC through the Ti-O-Co interfacial bonds. Consequently, it endows the Co-BDC with enhanced conductivity as well as the higher valence of Ti species in Ti3C2Tx, hence contributes a remarkable enhanced specific capacity. This work will provide a pathway to design advanced MOF/MXene materials for HSC.

Study on determination of 2-thioxothiazolidine-4-carboxylic Acid in urine by high performance liquid chromatography / 中华劳动卫生职业病杂志

Objective: To establish a high performance liquid chromatography method for the determination of 2-thioxothiazolidine-4-carboxylic acid (TTCA) in urine. Methods: After acidification with hydrochloric acid, TTCA in urine was first extracted by ethyl acetate with excessive sodium chloride, then gradient separated by a symmetry C18 column and then detected by a diode array detector. The quantification was based on a working curve of external standard method. Results: The linear relationship of TTCA in urine was good in the range of 0.03-10.00 mg/L, and the correlation coefficient was 0.9999. The detection limit and minimum quantitative concentration of TTCA in urine were 0.008 mg/L and 0.027 mg/L. The intra-assay precision of the method was 0.9%-1.4%, the inter-assay precision was 1.3%-3.5%, and the average recovery was 85.0%-92.7% while the concentrations of TTCA in urine was 0.8, 2.0 and 8.0 mg/L, respectively (n=6) . Conclusion: The gradient elution high performance liquid chromatography method has simple operation and high sensitivity, and it is suitable for the determination of TTCA on a low level in urine for occupational workers exposure to carbon disulfide.

In Situ Synthesis of Surface-Mounted Novel Nickel(II) Trimer-Based MOF on Nickel Oxide Hydroxide Heterostructures for Enhanced Methanol Electro-Oxidation.

Engineering the heterogeneous interface fusing MOFs and inorganic active component is an effective strategy to improve the electrochemical performance. Herein, we report a new Ni3-based MOF (denoted as CTGU-24) with an infrequent two-fold interpenetrating 3D (3,8)-connected network constructed from Ni(II) trimer and mixed tripodal tectonics for the electrocatalytic methanol oxidation reaction (MOR). In order to improve its stability and activities, the heterogeneous hybrid CTGU-24@NiOOH has been fabricated successfully via the first preparation of the NiOOH nanosphere and then in situ formation of CTGU-24 decorated on the NiOOH surface. Moreover, the integration of CTGU-24@NiOOH and different additives [acetylene black (AB) and ketjen black (KB)], resulting in the optimized hybrid sample AB&CTGU-24@NiOOH (4:4). It attains better MOR performance with an area-specific peak current density of 34.53 mA·cm-2 than pure CTGU-24 (14.99 mA·cm-2) and improved durability in an alkali medium. The new findings indicate that the CTGU-24@NiOOH heterostructure formed in situ and the integration of moderate additives are critical to optimizing and improving electrocatalytic activity of pure MOF crystalline material.

Common Strategy: Mounting the Rod-like Ni-Based MOF on Hydrangea-Shaped Nickel Hydroxide for Superior Electrocatalytic Methanol Oxidation Reaction.

Developing efficient metal-organic framework (MOF)-based electrocatalysts with improvable activity and persistence toward the methanol oxidation reaction (MOR) is attracting great research attention but still remains an enormous challenge. Herein, a facile strategy, hydrangea-shaped nickel hydroxide template-directed synthesis of the hierarchically structured Ni-MOF on the Ni(OH)2 heterocomposite (denoted as Ni-Ni) for efficient MOR, is developed. The unique hierarchical structure and synergistic effect of the heterocomposite afford more exposed active sites, a facile ion diffusion path, and improved conductivity, favorable for improving MOR catalytic performance. Remarkably, the optimized Ni-Ni-2 material delivers an excellent activity with a high peak current density (24.6 mA cm-2). Furthermore, to prove the universality of this strategy, NixCu1-x(OH)2 isometallic hydroxide was used as the precursor, and a series of MOF-74/CuxNi1-x(OH)2 (denoted as Ni-NiCu) heterogeneous materials have been prepared and could be used as an effective electrocatalyst to catalyze MOR. The results indicate that this strategy can be used in the synthesis of other new composite materials with specific hierarchical structures for a more efficient electrocatalytic system.

In situ synthesis of hierarchical NiCo-MOF@Ni1-xCox(OH)2 heterostructures for enhanced pseudocapacitor and oxygen evolution reaction performances.

Integrating the merits of different components to construct heterostructures for energy storage and conversion has attracted intensive attention. Herein, taking advantage of bimetallic MOFs and transition bimetal hydroxide, we have successfully used nanoflower-like Ni1-xCox(OH)2 as both the precursor and template to in situ construct three dimensional (3D) NiCo-MOF@Ni1-xCox(OH)2 (denoted as MOF@TMH) hierarchical heterostructures. Benefiting from the optimized composition with hierarchical heterostructures assembled by ultrathin nanosheets, MOF@TMH-2 possesses rich effective active sites and high electrochemical reactivity, delivering superior pseudocapacitor performance with a specific capacitance of 1855.3 F g-1 at 2 A g-1 and good rate performance. Besides, MOF@TMH-2 also exhibits excellent OER activity with small overpotentials of 193 mV and 310 mV at 10 and 100 mA cm-2, respectively.

Anatomical Study of the Accessory Tendon of the Extensor Hallucis Longus Muscle and Its Clinical Application

Background@#The accessory tendon of the extensor hallucis longus (ATEHL) muscle is a common abnormal structure, and its clinical significance remains debatable. In this study, we provide the incidence of the ATEHL and characterize its morphological types in Asian cadavers and investigate its clinical applications. @*Methods@#The tendons from 50 adult cadaveric feet, fixed in 10% formalin, were analyzed. We measured the length and width of both the ATEHL and the extensor hallucis brevis (EHB). @*Results@#All dissected specimens had an ATEHL. The first metatarsophalangeal joint was surrounded by an accessory tendon that inserted onto the joint capsule and the dorsal base of the proximal phalanx. We classified the ATEHL into 3 types based on their directions. Differences in ATEHL type based on sex were not statistically significant. @*Conclusions@#We found an ATEHL in all cadaveric specimens in this study. We surmise that the ATEHL acts as an antagonist with the EHB when the toe is extending, which might help prevent the occurrence of hallux valgus deformity.

Anatomical Study of the Accessory Tendon of the Extensor Hallucis Longus Muscle and Its Clinical Application

Background@#The accessory tendon of the extensor hallucis longus (ATEHL) muscle is a common abnormal structure, and its clinical significance remains debatable. In this study, we provide the incidence of the ATEHL and characterize its morphological types in Asian cadavers and investigate its clinical applications. @*Methods@#The tendons from 50 adult cadaveric feet, fixed in 10% formalin, were analyzed. We measured the length and width of both the ATEHL and the extensor hallucis brevis (EHB). @*Results@#All dissected specimens had an ATEHL. The first metatarsophalangeal joint was surrounded by an accessory tendon that inserted onto the joint capsule and the dorsal base of the proximal phalanx. We classified the ATEHL into 3 types based on their directions. Differences in ATEHL type based on sex were not statistically significant. @*Conclusions@#We found an ATEHL in all cadaveric specimens in this study. We surmise that the ATEHL acts as an antagonist with the EHB when the toe is extending, which might help prevent the occurrence of hallux valgus deformity.

The highly selective detecting of antibiotics and support of noble metal catalysts by a multifunctional Eu-MOF.

Designing novel multifunctional rare-earth metal-organic frameworks (MOFs) has attracted intensive attention. In particular, employing such materials for sensing or catalytic reactions is still very challenging. Here, a new 3D porous Eu(iii)-MOF, [Eu(cppa)(OH)]·xS (denoted as CTGU-19, S = solvent molecule, CTGU = China Three Gorges University), was synthesized by using 5-(4-carboxyphenyl)picolinic acid (H2cppa) as an organic ligand, and it shows a 3D (3,12)-connected topological net with the point symbol (420·628·818)(43)4, constructed from cubane-shaped tetranuclear europium building units. Interestingly, CTGU-19 can be used as a highly sensitive luminescent sensor to identify ornidazole (ODZ) and nitrofurantoin (NFT) at different excitation wavelengths. This result represents the first example of a lanthanide-metal-organic-framework (Eu-MOF) that can be employed as a discriminating fluorescent probe to recognize ODZ and NFT at different excitation wavelengths. Furthermore, after loading CTGU-19 with Ag and/or Au nanoparticles, the composites exhibit efficient catalytic performance for reducing 2-/3-/4-nitrophenols (2-/3-/4-NP), in which the unit mass reduction rate constants of Ag0.8Au0.2@CTGU-19 for 2-NP, 3-NP, and 4-NP reach 68.8, 53.80, and 52.34 s-1 g-1, respectively.

Synthesis of Semiconducting 2H-Phase WTe2 Nanosheets with Large Positive Magnetoresistance.

Tungsten ditelluride (WTe2) is provoking immense interest because of its unique electronic properties, but studies about its semiconducting hexagonal (2H) phase are quite rare. Herein, we report the synthesis of semiconducting 2H WTe2 nanosheets with large positive magnetoresistance, for the first time, by a simple lithium-intercalation-assisted exfoliation strategy. Systematic characterizations including high-resolution transmission electron microscopy, X-ray diffraction, and Raman and X-ray photoelectron spectroscopies provide clear evidence to distinguish the structure of 2H WTe2 nanosheets from the orthorhombic (Td) phase bulk counterpart. The corresponding electronic phase transition from metal to semiconductor is also confirmed by density of states calculation, optical absorption, and electrical transport property measurements. Besides, the 2H WTe2 nanosheets exhibit large positive magnetoresistance with values of up to 29.5% (10 K) and 16.2% (300 K) at 9 T. Overall, these findings open up a promising avenue into the exploration of WTe2-based materials in the semiconductor field.