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Metal–organic frameworks (MOFs) exhibit attractive performance in fields such as luminescence sensors and catalysis. We here developed a new MOF ({Cu2(DPQ)2(OBPBI)}n), briefly named Cu-MOF, which has been facilely obtained through the self-assembly of 4, 4′-(quinoxaline-2, 3-diyl)dibenzoic acid (H2DPQ), 1, 1′-[oxybis(4, 1-phenylene)]bis(1H-imidazole) (OBPBI), and CuCl2·2H2O under solvothermal conditions. Cu-MOF contains a paddle-wheel and binuclear copper oxygen cluster unit and forms a 2, 2, 6-connected two-dimensional (2D) net with the point symbol of {42·88·125}{4}2{8}. Luminescence investigations indicate that Cu-MOF has a selective fluorescent response to Fe3+and Cr3+ions in water, with detection limits low to 10–8M, at least three times reusability, and a wide pH applicable scope. A combined logic gate INHIBIT has been built based on the different signal inputs of Fe3+and Cr3+ions and emission intensity signal outputs, providing great potential for distinguishing Fe3+and Cr3+ions. Moreover, Cu-MOF has been successfully applied for the catalytical conversion of CO2to cyclic carbonates under solvent-free and mild conditions (0.1 mol % Cu-MOF, 3 mol % TBAB, 1 atm of CO2, 15 h, 85 °C), with up to 98% yield, 99% selectivity, and three times reusability.

The design of highly stable and dual-emission lanthanide metal–organic frameworks (Ln-MOFs) is promising for practical chemical sensor applications. Rational design and synthesis of photoresponsive organic ligands provide a feasible approach to achieving highly fluorescent dual-emission Ln-MOFs. In this study, a tetraphenylpyrazine-based AIE ligand, H4L, was synthesized and combined with lanthanide ions (including Sm3+, Eu3+, Gd3+, and Tb3+) to fabricate a series of Ln-MOFs named Ln-L. The single-crystal analysis revealed that all Ln-L belonged to the tetragonal space group P4212 and featured a 2-fold interpenetrated 3D structure. Leveraging rational design, Eu-L exhibited a sensitive response to tetracycline, making it a promising fluorescence sensor for tetracycline detection. The experiments demonstrated that Eu-L could rapidly and quantitatively detect tetracycline and its analogs within 30 s. The lowest detection limits for tetracycline, oxytetracycline, and chlortetracycline were 0.43, 0.92, and 0.81 μM, respectively. Additionally, the probe displayed excellent reusability and exceptional selectivity. A plausible sensing mechanism was proposed, supported by both experimental and theoretical analyses. Furthermore, the study discovered that on-site and real-time determination of TCs in aqueous solutions could be achieved by using luminescence test papers and composite films derived from Eu-L.

To construct a built-in electric field (BIEF) that facilitates the transport and separation of photogenerated carriers in C3N5can effectively promote its photocatalytic performance. Herein, cyano defects and K+intercalation co-modified C3N5(KACN-2) was successfully prepared via a simple method. Several structural characterizations deduced the proposed location of the cyano group. The cyano group induced local polarization and adjusted the energy level distribution inside the material, and the K+intercalation caused strong ion-dipole interactions in the framework of C3N5, these all resulted in the generation of a robust BIEF. KPFM characterization and Kanata-model revealed the robust BIEF in the KACN-2 with 2 times higher than that of CN. Density Functional Theory (DFT) calculations verified the promoted transport and separation of photogenerated carriers and optimized energy band distribution caused by the BIEF. CO2-TPD and O2-TPD confirmed the enhanced alkaline sites and oxygen adsorption capacity aroused by the charge density redistribution of K+intercalation and the electron-withdrawing character of cyano defects. The robust BIEF and enhanced oxygen adsorption capacity synergistically facilitated the KACN-2 (0.0299 min−1) to achieve a 3.8 times higher levofloxacin hydrochloride (LFH) removal than CN (0.0086 min−1) under visible light. EPR and RRDE measurement supportively illustrated the two-step one-electron reduction reaction mechanism. The degradation process of LFH follows three pathways and toxicity analysis confirmed they all effectively reduced potential secondary pollution to the water environment. This work realizes a simple method for constructing BIEF and provides a new perspective to enhance the photodegradation performance of C3N5to the water pollutants.

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by using hydrophilic TiO2modified glassy carbon electrodes for the first time. The differential pulse voltammetry (DPV) method is proposed to measure phosphate in water as pulse techniques offer higher sensitivity compared with the conventional cyclic voltammetry (CV) method. Hydrophilic TiO2films were obtained upon ultraviolet (UV) illumination after TiO2precursor emulsions were coated on the surfaces of glassy carbon electrodes, and used for phosphate determination. Contact angle measurements (around 23.4°) proved the good hydrophilicity of the TiO2modified surface upon UV illumination. A detection limit of 0.1 μg L−1is obtained, and a linear relationship (R2= 0.99) between the phosphate concentration (ranging from 0.1 μg L−1to 1 μg L−1) and the peak current was observed.

The seven-membered ring motifs are found in bioactive pharmaceuticals and a wide range of natural products, including alkaloids and terpenoids, which hold significant importance in synthetic chemistry and has garnered considerable attention from both academia and industry. Despite the challenges faced in the past decade, the total synthesis of natural products incorporating the non-aromatic cycloheptane skeletons remains a compelling pursuit. Recently, numerous elegant strategies for constructing the seven-membered ring system have been successfully developed. This review focuses on the recent advancements in this field from 2017 to April 2023, highlighting key transformations utilized to construct the non-aromatic cycloheptane core structures and serves as a valuable guide for synthetic chemists engaged in the total synthesis of natural products containing seven-membered ring motifs.

Rare earth elements were extracted using a sulfuric acid roasting-water leaching process. The effect of acid roasting on a new type of low-grade sedimentary rare earth ore found in Guizhou Province, China was analyzed using X-ray diffraction and scanning electron microscopy. A systematic study was conducted on process parameters such as amount of acid, roasting temperature, roasting time, water leaching temperature, and leaching time. The results reveal that the total recovery of rare earth elements reaches 81.37%, which is 3.1 times higher than that achieved through direct acid leaching, under the optimal conditions. In addition, the leaching rate of heavy rare earth elements reaches 72.53%. Rare earth elements and some other valuable metals are transformed into soluble sulfate through the local decomposition of clay minerals under the action of the sulfuric acid attack. The dissolution rates of aluminum, iron, and titanium ions are 34.94%, 17.05%, and 62.77%, respectively. The precipitation rate of Ti reaches 99%, and the loss of rare earth ions in the solution is less than 1%. Meanwhile, the results of a leaching kinetics analysis indicate that the leaching process of rare ions is controlled by diffusion. Precious metal ions such as iron and aluminum in the leaching solution can reduce the adsorption of rare earth ions by kaolinite. This study efficiently recovered rare earth ions under conditions of low calcination temperature and direct water leaching, resulting in reduced energy consumption of the extraction process and acidity of the leaching solution. These findings provide a solid foundation for the further separation and extraction of rare earth ions.

Radiation-tolerance and repairable flexible transistors and integrated circuits (ICs) with low power consumption have become hot topics due to their wide applications in outer space, nuclear power plants, and X-ray imaging. Here, we designed and developed novel flexible semiconducting single-walled carbon nanotube (sc-SWCNT) thin-film transistors (TFTs) and ICs. Sc-SWCNT solid-electrolyte-gate dielectric (SEGD) TFTs showcase symmetric ambipolar characteristics with flat-band voltages (VFB) of ∼0 V, high ION/IOFFratios (>105), and the recorded irradiation resistance (up to 22 Mrad). Moreover, flexible sc-SWCNT ICs, including CMOS-like inverters and NAND and NOR logic gates, have excellent operating characteristics with low power consumption (≤8.4 pW) and excellent irradiation resistance. Significantly, sc-SWCNT SEGD TFTs and ICs after radiation with a total irradiation dose (TID) ≥ 11 Mrad can be repaired after thermal heating at 100 °C. These outstanding characteristics are attributed to the designed device structures and key core materials including SEGD and sc-SWCNT.

The development of novel large-area flexible optoelectronic synaptic devices is of great interest for visual neuromorphic computing. In this paper, we have successfully manufactured 33 × 34 flexible carbon nanotube synaptic photogating transistor arrays via the roll-to-roll gravure printing technology using the mixture of photosensitive rhodamine 6G and poly(vinylidene fluoride-co-hexa-fluoropropylene) as the composite dielectric layer. The resulting thin-film transistor devices exhibit excellent electrical properties with high Ion/Ioff(>105), the maximum carrier mobility (10.71 cm2V−1s−1) and low operating voltage (−1.5 V∼ 0.5 V), and excellent optoelectronic synaptic properties, which are capable of performing not only the excitatory postsynaptic current and paired pulse facilitation but also complex biological synaptic functions such as optical writing and electrical erasure, dynamic learning and forgetting processes, and Pavlov's dog experiment. Significantly, the ultralow energy consumption per light spike event as low as 0.03 fJ can be achieved under the pulse UV light illumination. Moreover, according to the trend that the LTP/LTD curve conforms to the concave function, we successfully embed the specific update rules of our synaptic devices into the generative adversarial network (GAN) that can generate high-quality (7680 × 4096 pixels) images, which is impossible for the human eye to distinguish the difference between the original labels and real labels.

The variety of charge transport theories for organic semiconductors (OSCs) raises the question of which models should be selected for each case, and there is a lack of generalized understanding regarding various OSCs over the full range of crystallinity from single crystal to amorphous. Here, we report that the generalized Einstein relation (GER) can unify various theoretical models and predict charge transport in OSCs with various crystallinities, by altering the variance of the density of states and the delocalization degree in a Gaussian-distributed density of states. The GER also provides a good fitting to much of the experimental data of temperature- and gate-voltage-dependent mobility for different OSCs in transistors. Consequently, disorders of charge transport in various OSCs can be directly compared in the same map, which reveals how energetic disorder and the delocalization degree determine charge transport in organic devices.

In this paper, double hydrophilic ionic liquid block copolymers (ILBCs), poly poly[1-methyl-3-(2-methacryloyloxy propylimidazolium bromine)]-block-(N-isopropylacrylamide) (PMMPImB-b-PNIPAAm) was first synthesized by reversible additionfragmentation chain transfer (RAFT) and then attached on the surface of gold nanoparticles (Au NPs) via a strong gold-sulfur bonding for preparing hybrid nanoparticles (PMMPImB-b-PNIPAAm-@-Au NPs). The hybrid NPs had a three layers micelle-like structure, including a gold core, thermo-responsive inner shell and anion responsive outer corona. The self-assembling behavior of thermal- and anion-response from shell and corona were respectively investigated by change of temperature and addition of (CF3SO2)2N−. The results showed the hybrid NPs retained a stable dispersion beyond the lower critical solution temperature (LCST) because of the space or electrostatic protecting by outer PMMPImB. However, with increasing concentration of (CF3SO2)2N−, the micellization of self-assembling PMMPImB-b-PNIPAAm-@-Au NPs was induced to form micellar structure containing the core with hydrophobic PMMPImB-(CF3SO2)2N−surrounded by composite shell of Au NPs-PNIPAAm via the anionresponsive properties of ILBCs. These results indicated that the block copolymers protected plasmonic nanoparticles remain self-assembling properties of block copolymers when phase transition from outer corona polymer.

The Patient Health Questionnaire-9 (PHQ-9) has been widely used to screen depression symptoms. The present research aimed to assess the reliability and validity of PHQ-9, besides measurement invariance of the PHQ-9 across gender and age among Chinese university students. A total of 12,957 Chinese college students from 2 universities in Henan and Hainan provinces (China) completed the questionnaires via WeChat. This research reported the psychometric properties of PHQ-9 and measurement invariance of the PHQ-9 across gender and age among Chinese university students. Compared with 1-factor model, the 2-factor (affective factor and somatic factor) model of PHQ-9 showed a better fit index in Chinese university students. Without the last 2 items, the 2-factor model of the PHQ-9 showed satisfactory reliability, validity, and good fit index (e.g., Root mean square error of approximation = 0.060, Goodness-of-fit index = 0.982, Comparative fit index = 0.986, and Tucker-Lewis index = 0.974). The Cronbach’s alpha of PHQ-9 was 0.874. Multi-group analysis across gender and age demonstrated that measurement equivalency for the 2-factor model of the PHQ-9 was established (e.g., Root mean square error of approximation < 0.08, Comparative fit index > 0.90 and Tucker-Lewis index > 0.90). The 2-factor model of the PHQ-9 without the items of “movement” and “desire to die” showed a better fit index in Chinese university students. The measurement equivalence across gender and age for the 2-factor model of the PHQ-9 can be established among Chinese university students.

Unidirectional dewetting enables the production of large-area thin films with high efficiency at low cost. Herein, we report homogeneous unidirectional dewetting on large-area microdroplet arrays via gravity-induced deformation in droplets combined with alternating lyophilic/lyophobic patterns. This process allows the scaled-up deposition of thin films, including organic semiconductors and transition metal oxides, through the autogenous shrinkage of droplets, which further enables the fabrication of large-area organic thin-film transistor (OTFT) arrays. The resulting field-effect mobility and on/off ratio of the fully printed OTFTs exceeded 13 cm2V−1s−1and 108, respectively. Therefore, the presented dewetting method is promising to realize the roll-to-roll manufacture of large-area flexible electronics.

The organic thin film transistor (OTFT) fabricated with the polypeptide as a dielectric layer shows memory function. In order to investigate the effect of polypeptide structure on the performance of non-volatile transistor memory, the Fourier-transform IR (FT- IR) and Circular Dichiroism (CD) spectral of PMLG film has been applied, respectively. In conclusion, the memory transistor device fabricated with polypeptide as the ferroelectric exhibit promising behavior such as a large memory window, and the dipole moment of the amide group was considered as the main source of the memory function.