Improved Conductivity and in Situ Formed Heterojunction via Zinc Doping in CuBi2O4 for Photoelectrochemical Water Splitting.

As a photocathode with a band gap of about 1.8 eV, copper bismuthate (CuBi2O4) is a promising material for photoelectrochemical (PEC) water splitting. However, weak charge transfer capability and severe carrier recombination suppress the PEC performance of CuBi2O4. In this paper, the conductivity and carriers transport of CuBi2O4 are improved via introducing Zn2+ into the synthesis precursor of CuBi2O4, driving a beneficial 110 mV positive shift of onset potential in photocurrent. Detailed investigations demonstrate that the introduction of an appropriate amount of zinc leads to in situ segregation of ZnO which serves as an electron transport channel on the surface of CuBi2O4, forming heterojunctions. The synergistic effect of heterojunctions and doping simultaneously promotes the charge transfer and the carrier concentration. OCP experiment proves that ZnO/Zn-CuBi2O4 possesses better charge separation; the Mott-Schottky curve shows that the doping of Zn significantly enhances the carrier concentration; carrier lifetime calculated from time-resolved photoluminescence confirms faster extraction of carriers.

Progress of charge carrier dynamics and regulation strategies in 2D CxNy-based heterojunctions.

Two-dimensional carbon nitrides (CxNy) have gained significant attention in various fields including hydrogen energy development, environmental remediation, optoelectronic devices, and energy storage owing to their extensive surface area, abundant raw materials, high chemical stability, and distinctive physical and chemical characteristics. One effective approach to address the challenges of limited visible light utilization and elevated carrier recombination rates is to establish heterojunctions for CxNy-based single materials (e.g. C2N3, g-C3N4, C3N4, C4N3, C2N, and C3N). The carrier generation, migration, and recombination of heterojunctions with different band alignments have been analyzed starting from the application of CxNy with metal oxides, transition metal sulfides (selenides), conductive carbon, and Cx'Ny' heterojunctions. Additionally, we have explored diverse strategies to enhance heterojunction performance from the perspective of carrier dynamics. In conclusion, we present some overarching observations and insights into the challenges and opportunities associated with the development of advanced CxNy-based heterojunctions.

Dynamics of Puccinia striiformis f. sp. tritici Urediniospores and Its Relationship with Meteorological Factors in Mianyang, China.

Stripe rust, caused Puccinia striiformis f. sp. tritici (Pst), is one of the main diseases of wheat worldwide. Mianyang of Sichuan province in southwest in China is one of main regions for winter Pst inoculum production and spring epidemic, and provides urediniospores for infecting wheat in the surrounding regions. Understanding the urediniospore dynamics is important to predict and manage stripe rust. In this study, spore trapping coupled with a TaqMan real-time quantitative PCR (TaqMan-qPCR) method was used to monitor airborne Pst urediniospores from December 2019 to December 2022 in Mianyang. Weather conditions (temperature, relative humidity, daily sunshine duration and precipitation) were collected for the same period. These data were used to study the relationship of airborne urediniospore density with climatic conditions. The results showed that Pst urediniospores were captured all year round, and the annual peak of urediniospore densities occurred in the period from March to April in which the urediniospores accounted for the largest proportion of the annual total urediniospores. The density of urediniospores in the period of March to April was linearly related to the average sunshine duration of 20 days and average temperature of 15 days prior to the final day of a 7-day trapping period. This relationship needs to be tested in other regions where Pst can sporulate during the winter before it can be integrated with Pst infection conditions to predict rust development.

High-Performance and Low-Power p-Channel Transistors Based on Monolayer Be2C.

The advantages of 2D materials in alleviating the issues of short-channel effect and power dissipation in field-effect transistors (FETs) are well recognized. However, the progress of complementary integrated circuits has been stymied by the absence of high-performance (HP) and low-power (LP) p-channel transistors. Therefore, we conducted an investigation into the electronic and ballistic transport characteristics of monolayer Be2C, which features quasi-planar hexacoordinate carbons, by employing nonequilibrium Green's function combined with density functional theory. Be2C monolayer has planar anticonventional bonds and a direct bandgap of 1.53 eV. The Ion of p-type Be2C HP FETs can achieve a remarkable 2767 µA µm-1. All of the device properties of 2D Be2C FETs can exceed the demands of the International Roadmap for Devices and Systems. The excellent properties of Be2C as a 2D p-orbital material with a high hole mobility are discussed from different aspects. Our findings thus illustrate the tremendous potential of 2D Be2C for the next generation of HP and LP electronics applications.

Enhancing Photocatalytic-Transfer Semi-Hydrogenation of Alkynes Over Pd/C3 N4 Through Dual Regulation of Nitrogen Defects and the Mott-Schottky Effect.

The selective hydrogenation of alkynes is an important reaction; however, the catalytic activity and selectivity in this reaction are generally conflicting. In this study, ultrafine Pd nanoparticles (NPs) loaded on a graphite-like C3 N4 structure with nitrogen defects (Pd/DCN) are synthesized. The resulting Pd/DCN exhibits excellent photocatalytic performance in the transfer hydrogenation of alkynes with ammonia borane. The reaction rate and selectivity of Pd/DCN are superior to those of Pd/BCN (bulk C3 N4 without nitrogen defects) under visible-light irradiation. The characterization results and density functional theory calculations show that the Mott-Schottky effect in Pd/DCN can change the electronic density of the Pd NPs, and thus enhances the hydrogenation selectivity toward phenylacetylene. After 1 h, the hydrogenation selectivity of Pd/DCN reaches 95%, surpassing that of Pd/BCN (83%). Meanwhile, nitrogen defects in the supports improve the visible-light response and accelerate the transfer and separation of photogenerated charges to enhance the catalytic activity of Pd/DCN. Therefore, Pd/DCN exhibits higher efficiency under visible light, with a turnover frequency (TOF) of 2002 min-1 . This TOF is five times that of Pd/DCN under dark conditions and 1.5 times that of Pd/BCN. This study provides new insights into the rational design of high-performance photocatalytic transfer hydrogenation catalysts.

Dynamics of Puccinia striiformis f. sp. tritici Urediniospores in Longnan, a Critical Oversummering Region of China.

Wheat stripe rust, caused by Puccinia striiformis f. sp. tritici Erikss. (Pst), is a devastating disease resulting in yield reduction. Because the temperature limits the overwintering and oversummering of Pst, it cannot complete the whole year cycle in most areas of China. Longnan, located in the southeast of Gansu Province, is one of the annual cycle areas of Pst, which can supply urediniospores in autumn to eastern wheat-growing areas in China. In this study, a TaqMan real-time quantitative PCR (TaqMan-qPCR) detection system for Pst urediniospores was established, and the detection limit was a single urediniospore. The dynamics of Pst urediniospores in Longnan were monitored by spore trapping and TaqMan-qPCR for 3 years. Meanwhile, the meteorological conditions including air temperature, relative humidity, and precipitation were recorded. Results showed that Pst urediniospores can be captured from March to December, and two peaks of urediniospore density appeared in May and June, respectively. The density of urediniospore is closely related to temperature and precipitation from March to June. In addition, we found that the density of Pst urediniospore had the peak value when the average air temperature was 10 to 21°C, and the relative humidity was 60 to 85% from May to June. The exponential model could describe the variation of Pst urediniospore density based on average temperature and precipitation from March to June. It is worth mentioning that the exponential model based on average temperature 7 days before spore capture has a great advantage in predicting the urediniospore density in the air. This study laid a foundation for establishment of a prediction model for wheat stripe rust based on the density of urediniospores and meteorological factors.

Structural, electronic and optical properties of monolayer InGeX3(X = S, Se, Te) by first-principles calculations.

Recently, two-dimensional materials have attracted enormous attentions for electronic and optoelectronic applications owing to their unique surface structures and excellent physicochemical properties. Herein, the structural, electronic and optical properties of a series of novel monolayer InGeX3(X = S, Se, Te) materials are investigated systematically by means of comprehensive first-principles calculations. All these three materials exhibit hexagonal symmetries and dynamical stabilities with no imaginary phonon mode. For monolayer InGeX3(X = S, Se, Te), there exist obvious In-X ionic bonds and the partially covalent interactions of Ge-Ge and Ge-X. By using the HSE06 method, the band gaps of monolayer InGeX3are predicted to 2.61, 2.24 and 1.80 eV, respectively. Meanwhile, thep-sorbital hybridizations are happened between X and In atoms in the conduction band regions and their interactions become smaller with the increase of X atomic number. In addition, the dielectric function, absorption coefficient and reflectivity spectra of monolayer InGeS3, InGeSe3and InGeTe3show the strong optical peaks along the in-plane direction in the UV light region. The definite bandgaps and optical properties make monolayer InGeX3(X = S, Se, Te) materials viable candidates for future electronic and optoelectronic applications.

Clinical efficacy of botulinum toxin type A on acute acquired comitant esotropia.

AIM: To investigate the effects of micro-injection of botulinum toxin A (BTXA) on acute acquired comitant esotropia (AACE). METHODS: A total of 33 AACE patients who underwent BTXA micro-injection at Renmin Hospital of Wuhan University from September 1st, 2019 to July 1st, 2021 were retrospective analyzed. Esotropia, eye alignment, stereopsis, and complications were examined at baseline (except complications), 1wk, 1, 3, and 6mo after injection. RESULTS: The average angle of deviation before injection was (+20.24±6.80)Δ at near and (+24.76±6.43)Δ at distance, while (+5.15±5.85)Δ at near and (+7.30±6.17)Δ at distance 6mo after treatment (P<0.05). Six months after injection, the stereopsis of patients had improved. The number of patients having no stereopsis (>800 seconds of arc) decreased from 11 to 3. The number of patients having peripheral stereopsis (300-800 seconds of arc), macular stereopsis (70-200 seconds of arc) and central concave stereopsis (≤60 seconds of arc) increased from 10 to 11, 10 to 12, and 2 to 7, respectively. At the follow-ups at 1wk, 1, 3, and 6mo after injection, success rates were 96.97%, 96.97%, 93.94% and 87.88%, respectively. One week after injection, two patients (6.07%) showed subconjunctival hemorrhage; three patients (9.09%) showed limited eye movement and one patient (3.03%) showed mild vertical strabismus. All the symptoms disappeared by the final follow-up. CONCLUSION: Micro-injection of BTXA can reduce diplopia and improve binocular vision function of AACE patients. Furthermore, the operation is relatively safe with few complications, making it an ideal treatment modality for AACE.

Tunneling transport of 2D anisotropic XC (X = P, As, Sb, Bi) with a direct band gap and high mobility: a DFT coupled with NEGF study.

Direct bandgap and significant anisotropic properties are crucial and beneficial for nanoelectronic applications. In this work, through first-principles calculations, we investigate novel two-dimensional (2D) α-XC (X = P, As, Sb, Bi) materials, which possess a direct bandgap of 0.73 to 1.40 eV with remarkable anisotropic electronic properties. Intriguingly, 2D α-XC presents the highest electron mobility near 8 × 103 cm2 V-1 s-1 along the Γ-X direction. Moreover, the transfer characteristics of the 2D α-XC TFETs are thoroughly assessed through NEGF methods. AsC TFETs demonstrate an on-state current larger than 2.2 × 103 µA µm-1, which can satisfy the International Technology Roadmap for Semiconductors (ITRS) for high-performance requirements. In particular, the minimum value of subthreshold swing of devices is as low as 15 mV dec-1, indicating excellent device switching characteristics. The relevant calculation results show that 2D α-XC monolayers could be a promising candidate in next-generation high-performance device applications.

Self-cycled photo-Fenton-like system based on an artificial leaf with a solar-to-H2O2 conversion efficiency of 1.46.

Millions of families around the world remain vulnerable to water scarcity and have no access to drinking water. Advanced oxidation processes (AOPs) are an effective way towards water purification with qualified reactive oxygen species (ROSs) while are impeded by the high-cost and tedious process in either input of consumable reagent, production of ROSs, and the pre-treatment of supporting electrolyte. Herein, we couple solar light-assisted H2O2 production from water and photo-Fenton-like reactions into a self-cyclable system by using an artificial leaf, achieving an unassisted H2O2 production rate of 0.77 µmol/(min·cm2) under 1 Sun AM 1.5 illumination. Furthermore, a large (70 cm2) artificial leaf was used for an unassisted solar-driven bicarbonate-activated hydrogen peroxide (BAP) system with recycled catalysts for real-time wastewater purification with requirements for only water, oxygen and sunlight. This demonstration highlights the feasibility and scalability of photoelectrochemical technology for decentralized environmental governance applications from laboratory benchtops to industry.

The Effect of Different Treatment Methods on Acute Acquired Concomitant Esotropia.

Objective: The application of botulinum toxin type A (BTXA) in the treatment of paralytic strabismus has been recognized, but there are few studies on the treatment of acute acquired comitant esotropia (AACE). This study was aimed to investigate the clinical characteristics of AACE and compare the therapeutic effects of BTXA and traditional surgery. Methods: 78 patients with AACE in Renmin Hospital of Wuhan University between March 2019 and March 2021 were reviewed. The relevant medical records of the patients were collected, and they were divided into surgical group (n = 46) and botulinum toxin type A (BTXA) group (n = 32) according to different treatment approaches. The surgical group was treated with squint correction, whereas the BTXA group was treated with microinjection of BTXA in MR. Eye alignment, esotropia, stereopsis, and complications were examined before and after treatment in both groups. Results: The refractive status of 78 patients with AACE was mostly myopic refractive error. In general, the angle of esotropia at distance was larger than which at near, with a statistically significant difference. At follow-up assessments of 1 week, 1 month, 3 months, and 6 months after treatment, the total effective rates of the surgical group and the BTXA group were 100% and 90.48%, respectively. The residual angle of esotropia of both groups was lower after treatment. Additionally, the incidence rate of complications in the BTXA group was significantly lower than that in the surgical group. Conclusion: AACE occurs mostly in people with myopic refractive errors and is associated with prolonged near work. Besides surgical treatment, micro-injection of BTXA is also an effective and safe treatment for AACE.

A machine-learning approach to discerning prevalence and causes of myopia among elementary students in Hubei.

OBJECTIVE: Our aim is to establish a machine-learning model that will enable us to investigate the key factors influencing the prevalence of myopia in students. METHODS: We performed a cross-sectional study that included 16,653 students from grades 1-3 across 17 cities in Hubei Province. We used questionnaires to discern levels of participation in potential factors contributing to the development of myopia. The relative importance of potential contributors was ranked using machine-learning methods. The students' visual acuity (VA) was measured and those with logMAR VA of > 0.0 underwent a autorefraction test to determine students' refraction status. RESULTS: The prevalence of myopia in grades 1, 2, and 3 was 14.70%, 20.54% and 28.93%, respectively. Myopia rates among primary school students in provincial capital city (32.35%) were higher than those in other urban (23.03%) and rural (14.82%) areas. Children with non-myopic parents, only one myopic parent, or both parents having myopia exhibited myopic rates of 16.36%, 25.18%, and 41.37%, respectively. Myopia prevalence was higher in the students who continued to use their eyes at close range for a long time and lower in those engaged longer in outdoor activities. The machine-learning model determined that the top three contributing factors were the students' age (0.36), followed by place of residence (0.34), starting age of education (0.21). CONCLUSION: The overall prevalence of myopia was 21.52%. Children's age and place of residence were the important influencing factors, but genetics and environmental were also played key roles in myopia development.

Clinical characteristics and aetiology of acute acquired comitant esotropia.

CLINICAL RELEVANCE: Acute acquired comitant esotropia (AACE) is characterised by the acute onset of diplopia which affects work and life. BACKGROUND: To describe the clinical characteristics and discuss the aetiology of acute acquired comitant esotropia. METHODS: The medical records of 51 patients with AACE were retrospectively analysed, and their age, occupation, daily average time spent on near work, angle of deviation, refractive error and aetiology were analysed. RESULTS: The age at onset of AACE was eight to 55 years. Thirty-nine patients were aged 12 to 36 years (76.5%), and 42 patients (82.4%) were myopic. The angle of deviation was 20Δ (12Δ to 35Δ) during near fixation and 25Δ (18Δ to 40Δ) during distance fixation. The deviation during distance fixation was larger than that during near fixation, the difference being statistically significant (p < 0.001). The daily average time of near work before onset was 9.0 h (8.0 h to 10.0 h); 35 patients (68.6%) spent more than 8 h performing near work. Their occupations included students, accountants, information technology staff, and those who required electronic use for a long time. There is no correlation between the angle of deviation and the time of near work (p > 0.05). Among the 51 patients, three had intracranial diseases. Diplopia resolved in 47 cases following treatment. The angle of deviation post-treatment was 0Δ (0Δ to 5Δ) during near and 0Δ (0Δ to 3Δ) during distance fixation. CONCLUSION: AACE occurs mostly in myopic older children and adults. The onset of esotropia is related to long-term near work. AACE patients mostly present an angle of deviation that is larger during distance than near fixation. Intracranial disease is an infrequent but important cause of AACE that needs to be excluded in all cases.

First-principles study on the electronic structures and contact properties of graphene/XC (X = P, As, Sb, and Bi) van der Waals heterostructures.

The electrical contacts at the van der Waals (vdW) interface between two-dimensional (2D) semiconductors and metal electrodes could dramatically affect the device performance. Herein, we construct a series of graphene (Gr)/XC (X = P, As, Sb, and Bi) vdW heterostructures, in which XC monolayers have aroused considerable attention recently as an emerging class of 2D semiconductors. The electronic structures and contact properties of Gr/XC vdW heterostructures are investigated systematically using first-principles calculations. The band structures indicate that both Gr/PC and Gr/AsC heterostructures form n-type Schottky contacts with Schottky barrier heights (SBHs) of 0.01 eV and 0.43 eV, respectively, while both Gr/SbC and Gr/BiC heterostructures preferably form Ohmic contacts. The different X atoms result in different work functions, electron flows, charge distributions and orientations of the dipole moment in Gr/XC heterostructures. Moreover, the tunneling probabilities increase with the increasing atom radius of X from P to Bi, indicating the most improved current and smaller contact resistance at the interfaces of Gr/BiC compared to Gr/PC, Gr/AsC and Gr/SbC heterostructures. Our work could provide meaningful information for designing high-performance nanoelectronic devices based on Gr/XC heterostructures.

GO/Bi2S3 Doped PVDF/TPU Nanofiber Membrane with Enhanced Photothermal Performance.

Photothermal conversion materials have attracted wide attention due to their efficient utilization of light energy. In this study, a (GO)/Bi2S3-PVDF/TPU composite nanofiber membrane was systematically developed, comprising GO/Bi2S3 nanoparticles (NPs) as a photothermal conversion component and PVDF/TPU composite nanofibers as the substrate. The GO/Bi2S3 NPs were synthesized in a one-step way and the PVDF/TPU nanofibers were obtained from a uniformly mixed co-solution by electrospinning. GO nanoparticles with excellent solar harvesting endow the GO/Bi2S3-PVDF/TPU membrane with favorable photothermal conversion. In addition, the introduction of Bi2S3 NPs further enhances the broadband absorption and photothermal conversion properties of the GO/Bi2S3-PVDF/TPU composite membrane due to its perfect broadband absorption performance and coordination with GO. Finally, the results show that the GO/Bi2S3-PVDF/TPU composite membrane has the highest light absorption rate (about 95%) in the wavelength range of 400-2500 nm. In the 300 s irradiation process, the temperature changes in the GO/Bi2S3-PVDF/TPU composite membrane were the most significant and rapid, and the equilibrium temperature of the same irradiation time was 81 °C. Due to the presence of TPU, the mechanical strength of the composite film was enhanced, which is beneficial for its operational performance. Besides this, the morphology, composition, and thermal property of the membranes were evaluated by corresponding test methods.

DFT coupled with NEGF study of the electronic properties and ballistic transport performances of 2D SbSiTe3.

Identifying novel 2D semiconductors with promising electronic properties and transport performances for the development of electronic and optoelectronic applications is of utmost importance. Here, we show a detailed study of the electronic properties and ballistic quantum transport performance of a new 2D semiconductor, SbSiTe3, based on density functional theory (DFT) and non-equilibrium Green's function (NEGF) formalism. Promisingly, monolayer SbSiTe3 owns an indirect band gap of 1.61 eV with a light electron effective mass (0.13m0) and an anisotropic hole effective mass (0.49m0 and 1.34m0). The ballistic performance simulations indicate that the 10 nm monolayer SbSiTe3 n- and p-MOSFETs display a steep subthreshold swing of about 80 mV dec-1 and a high on/off ratio (106), which indicate a good gate-controlling capability. As the channel length of SbSiTe3 decreases to 5 nm, its p-MOSFET also effectively suppresses the intra-band tunneling. Therefore, 2D SbSiTe3 is a potential semiconductor for future nanoelectronics.

Multilayer Nanofiber Composite Separator for Lithium-Ion Batteries with High Safety.

An original Von Koch curve-shaped tipped electrospinneret was used to prepare a polyimide (PI)-based nanofiber membrane. A multilayer Al2O3@polyimide/polyethylene/Al2O3@polyimide (APEAP) composite membrane was tactfully designed with an Al2O3@ polyimide (AP) membrane as outer shell, imparting high temperature to the thermal run-away separator performance and a core polyethylene (PE) layer imparts the separator with a thermal shut-down property at low temperature (123 °C). An AP electrospun nanofiber was obtained by doping Al2O3 nanoparticles in PI solution. The core polyethylene layer was prepared using polyethylene powder and polyterafluoroethylene (PTFE) miniemulsion through a coating process. The addition of PTFE not only bonds PE power, but also increases the adhesion force between the PE and AP membranes. As a result, the multilayer composite separator has high safety, outstanding electrochemical properties, and better cycling performance as a lithium-ion battery separator.

Salt-Assisted Synthesis of 3D Porous g-C3N4 as a Bifunctional Photo- and Electrocatalyst.

Graphitic carbon nitride (g-C3N4), characterized with a suitable bandgap, has aroused great interest as a robust and efficient catalyst for solar energy utilization. Herein, we introduce a new strategy to fabricate a three-dimensional (3D) porous g-C3N4 by a facile NaCl-assisted ball-milling strategy. The porous structure-induced advantages, such as a higher specific surface area, more efficient charge separation, and faster electron-transfer efficiency, enable the 3D porous g-C3N4 to achieve impressive properties as a bifunctional catalyst for both photocatalytic hydrogen evolution and electrocatalytic oxygen evolution reaction (OER). As a result, the 3D porous g-C3N4 exhibits a hydrogen evolution rate of 598 µmol h-1 g-1 with an apparent quantum yield of 3.31% at 420 nm for photocatalytic H2 generation, which is much higher than that of the bulk g-C3N4. Simultaneously, the porous g-C3N4 also presents an attractive OER performance with a low onset potential of 1.47 V (vs reversible hydrogen electrode) in an alkaline electrolyte after rational cobalt-doping. Accordingly, the NaCl-assisted ball-milling strategy paves the way to the rational design of a controllable porous structure.

Modulating Epitaxial Atomic Structure of Antimonene through Interface Design.

Antimonene, a new semiconductor with fundamental bandgap and desirable stability, has been experimentally realized recently. However, epitaxial growth of wafer-scale single-crystalline monolayer antimonene preserving its buckled configuration remains a daunting challenge. Here, Cu(111) and Cu(110) are chosen as the substrates to fabricate high-quality, single-crystalline antimonene via molecular beam epitaxy (MBE). Surface alloys form spontaneously after the deposition and postannealing of Sb on two substrates that show threefold and twofold symmetry with different lattice constants. Increasing the coverage leads to the epitaxial growth of two atomic types of antimonene, both exhibiting a hexagonal lattice but with significant difference in lattice constants, which are observed by scanning tunneling microscopy. Scanning tunneling spectroscopy measurements reveal the strain-induced tunable bandgap, in agreement with the first-principles calculations. The results show that epitaxial growth of antimonene on different substrates allow the electronic properties of these films to be tuned by substrate-induced strain and stress.

Recent progress in 2D group IV-IV monochalcogenides: synthesis, properties and applications.

Coordination-related, 2D structural phase transitions are a fascinating facet of 2D materials with structural degeneracy. Phosphorene and its new phases, exhibiting unique electronic properties, have received considerable attention. The 2D group IV-IV monochalcogenides (i.e. GeS, GeSe, SnS and SnSe) like black phosphorous possess puckered layered orthorhombic structure. The 2D group IV-IV monochalcogenides with advantages of earth-abundance, less toxicity, environmental compatibility and chemical stability, can be widely used in optoelectronics, piezoelectrics, photodetectors, sensors, Li-batteries and thermoelectrics. In this review, we summarized recent research progress in theory and experiment, which studies the fundamental properties, applications and fabrication of 2D group IV-IV monochalcogenides and their new phases, and brings new perspectives and challenges for the future of this emerging field.