Engineering sodium alginate-SiO2 composite beads for efficient removal of methylene blue from water.

The lack of sufficient active binding sites in commonly reported sodium alginate (SA)-based porous beads hampers their performances in adsorption of water contaminants. To address this problem, porous SA-SiO2 beads functionalized with poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) are reported in this work. Due to the porous properties and the existence of abundant sulfonate groups, the obtained composite material SA-SiO2-PAMPS shows excellent adsorption capacity toward cationic dye methylene blue (MB). The adsorption kinetic and adsorption isotherm studies reveal that the adsorption process fits closely to pseudo-second-order kinetic model and Langmuir isotherm model, respectively, suggesting the existence of chemical adsorption and monolayer adsorption behavior. The maximum adsorption capacity obtained from Langmuir model is found to be 427.36, 495.05, and 564.97 mg/g under 25, 35, and 45 °C, respectively. The calculated thermodynamic parameters indicate that MB adsorption on SA-SiO2-PAMPS is spontaneous and endothermic.

Two-dimensional IV-VA3 monolayers with enhanced charge mobility for high-performance solar cells.

High-performance photovoltaics (PVs) constitute a subject of extensive research efforts, in which silicon (Si)-based solar cells (SCs) have been widely commercialized. However, the low carrier mobility of Si-based SCs can limit the effective charge separation, thereby negatively impacting the device performance. Here, via calculating the physicochemical and PV performance based on density functional theory, we demonstrate SCs based on two-dimensional (2D) group IV and V compounds with an AX3 configuration. Firstly, the cleavage energies of AX3 (A = Si, Ge; X = P, As, and Sb) are calculated to be less than 1 J m-2, providing an experimental feasibility to be exfoliated from the corresponding bulk. Secondly, electronic and optical properties have been systematically investigated. To be specific, the band gap of monolayer AX3 falls in the range of 1.11-1.27 eV, which is comparable with that of Si. Significantly, the electron mobility of monolayer AX3 can reach as high as ∼30 000 cm2 V-1 s-1, which is one order of magnitude higher than that of Si. Furthermore, the optical absorbance of monolayer SiAs3, SiP3 and GeAs3 exhibits high coefficients in visible light. Therefore, we believe that our designed AX3-based PV systems with power conversion efficiency of 20% can offer great potential in the application of high-performance two-dimension-based PVs.

Evaluation of coating uniformity for the digestion-aid tablets by portable near-infrared spectroscopy.

Process analysis can effectively stabilize pharmaceutical quality and optimize the control of production process. For the sustained-release digestion-aid tablets, the coating film thickness is an important indicator to measure the quality of products. Traditional method mainly spot-checks tablets and measures with visual microscopy, which is time-consuming and laborious. This study attempted to use a portable near-infrared spectroscopy for rapid detection of a Chinese medicine tablets from production line. First, PLS regression models were established for coating film at twelve different locations of the tablet section, and the results showed that the correlation coefficients of training and validation sets were all over 0.80. Subsequently, the twelve locations were divided into six groups to further establish regressions. After chemometrics optimization, the optimal of six group models were generally better than single location models, with Rc2 and Rv2 all above 0.85, and RMSEV values all below 2.0. The mean relative error of prediction of the optimal model was 9.49%. The pharmaceutical process detection based on the portable NIR spectroscopy met the demand of managing digestion-aid tablet coating data conveniently. The proposed approach can successfully realize on-site and online pharmaceutical monitoring and has a promising practical value.

Two-dimensional InSb/GaAs- and InSb/InP-based tandem photovoltaic device with matched bandgap.

The past several years have witnessed remarkable research efforts to develop high-performance photovoltaics (PVs), to curtail the energy crisis by avoiding dependence on traditional fossil fuels. In this regard, there is an urgent need to accelerate research progress on new low-dimensional semiconductors with superior electronic and optical properties. Herein, combining abundant related PV experimental data in the literature and our systematic theoretical calculations, we propose two-dimensional (2D) InSb/GaAs and InSb/InP-based tandem PVs with high solar-to-electric efficiency up to near 30.0%. Firstly, according to first-principles calculations, the stability, electronic and optical properties of single-layer group-III-V materials (XY, X = Ga and In, Y = N, P, As, Sb, and Bi) are systematically introduced. Next, due to the high bandgap (Eg) of GaAs and InP being a perfect match with the low Eg of InSb, InSb/GaAs- and InSb/InP-based tandem PVs are constructed. In addition, the complementary absorption spectra of these two subcells can facilitate the achievement of high tandem power conversion efficiency. Furthermore, we have analyzed in detail the influencing factors for PCE and the physical mechanism of the optimized match between the top and bottom subcells in the tandem configurations. Our designed 2D-semiconductor-based PVs can be expected to bring a new perspective for future commercialized high-efficiency energy devices.

Electric Field Induced Electrorotation of 2D Perovskite Microplates.

High precision-controlled movement of microscale devices is crucial to obtain advanced miniaturized motors. In this work, we report a high-speed rotating micromotor based on two-dimensional (2D) all-inorganic perovskite CsPbBr3 microplates controlled via alternating-current (AC) external electric field. Firstly, the device configuration with optimized electric field distribution has been determined via systematic physical simulation. Using this optimized biasing configuration, when an AC electric field is applied at the four-electrode system, the microplates suspended in the tetradecane solution rotate at a speed inversely proportional to AC frequency, with a maximum speed of 16.4 × 2π rad/s. Furthermore, the electrical conductivity of CsPbBr3 microplates has been determined in a contactless manner, which is approximately 10-9-10-8 S/m. Our work has extended the investigations on AC electric field-controlled micromotors from 1D to 2D scale, shedding new light on developing micromotors with new configuration.

High Annealing Stability of InAlZnO Nanofiber Field-Effect Transistors with Improved Morphology by Al Doping.

In2O3 nanofibers usually suffer a high off-current and consequent low on/off current ratio, as well as a large negative threshold voltage (Vth). Furthermore, regarding Zn doped binary-cation In2O3 nanofibers, severe thermal diffusion of Zn elements can result in deteriorated electrical performance when annealed at high temperature. Here, we applied an electrospinning technique to obtain ternary-cation IAZO nanofibers with controllable Vth and chemical stoichiometry. The presence of the Al element in IAZO nanofibers can lead to more superior microstructure with improved uniformity, lower surface defect, and superior metal-oxide-metal lattice at high annealing temperature. Consequently, our Al-doped ternary-cation IAZO devices exhibited an improved on/off current ratio of 107 and a high electron mobility of ∼10 cm2 V-1 s-1. Moreover, the electron mobility can be increased to 30 cm2 V-1 s-1 in our low-voltage operated FETs with high-k AlOx as the dielectric layer, which can be envisioned to exhibit vast implications for high-performance transparent electronics.

Two-Dimensional BAs/InTe: A Promising Tandem Solar Cell with High Power Conversion Efficiency.

Tandem solar cells (SCs) connecting two subcells with different absorption bands have the potential to reach the commercialized photovoltaic standard. However, the performance improvement of tandem architectures is still a challenge, primarily owing to the mismatch of band gaps in two subcells. Here, we demonstrate a two-dimensional (2D) BAs/InTe-based tandem SC, which could achieve solar-to-electric conversion efficiency higher than 30%. First, the narrow band gap of hexagonal single-layer BX (X = P and As) and wide band gap of single-layer YZ (Y = Ga and In, Z = S, Se, and Te) are found to have high thermodynamic stability based on density functional theory calculations. Next, considering narrow and wide band gaps at the HSE06 functional, single-layer BX/YZ-based tandem SCs are built to effectively capture a broad-band solar spectrum by combining such two subcells. Since the band gap of single-layer BAs matches well with that of the InTe monolayer, the power conversion efficiency of BAs/InTe-based tandem SC can reach as high as 30.2%. Moreover, it is important to note that the used materials, including few-layer GaZ and InSe, have been experimentally prepared, which strongly supports the high feasibility of the designed 2D tandem SCs in this work. Our constructed 2D-material-based devices can be competitive in realizing commercialized high-performance tandem SCs.

Advances of 2D bismuth in energy sciences.

Since graphene has been successfully exfoliated, two-dimensional (2D) materials constitute a vibrant research field and open vast perspectives in high-performance applications. Among them, bismuthene and 2D bismuth (Bi) are unique with superior properties to fabricate state-of-the-art energy saving, storage and conversion devices. The largest experimentally determined bulk gap, even larger than those of stanene and antimonene, allows 2D Bi to be the most promising candidate to construct room-temperature topological insulators. Moreover, 2D Bi exhibits cyclability for high-performance sodium-ion batteries, and the enlarged surface together with the good electrochemical activity renders it an efficient electrocatalyst for energy conversion. Also, the air-stability of 2D Bi is better than that of silicene, germanene, phosphorene and arsenene, which could enable more practical applications. This review aims to thoroughly explore the fundamentals of 2D Bi and its improved fabrication methods, in order to further bridge gaps between theoretical predictions and experimental achievements in its energy-related applications. We begin with an introduction of the status of 2D Bi in the 2D-material family, which is followed by descriptions of its intrinsic properties along with various fabrication methods. The vast implications of 2D Bi for high-performance devices can be envisioned to add a new pillar in energy sciences. In addition, in the context of recent pioneering studies on moiré superlattices of other 2D materials, we hope that the improved manipulation techniques of bismuthene, along with its unique properties, might even enable 2D Bi to play an important role in future energy-related twistronics.

[Application prospect of new technology and new equipment in production of Chinese patent medicine].

At present,the production equipment and process of Chinese patent medicines still have many problems including high energy consumption,low efficiency,high pollution,and low intelligence,which seriously hinder the transformation,upgrading and modernized development of traditional Chinese medicine industry. With the emergence of various new pharmaceutical technologies and the application of technologies of other fields in traditional Chinese medicine industry,the development of Chinese patent medicine has ushered in new opportunities. The processes such as pulverization,mixing,extraction,separation,concentration,drying and sterilization are unique for the production of Chinese patent medicine. These main features can be distinguished from the manufacturing process of chemical drugs,determining the characteristics of the production process and equipment of Chinese patent medicine. In this paper,each operation unit was mentioned to summarize and analyze the new equipment and new technologies with advantages and characteristics in recent years from the perspectives of definition,principle,classification and application. Among them,the automatic spray device of the mixer,the extraction and separation equipment of volatile oil,and the crane basket-type circulation extraction technology,composite multi-layer spiral vibration countercurrent drying,and vibration sterilization equipment all have rapid development in recent years,with great prospects in the production of Chinese patent medicines. In this paper,we also analyzed some problems existing in the production equipment and technology of Chinese patent medicine and the key factors restricting the development of Chinese patent medicine,discussed the transformation of Chinese patent medicine production from traditional to modern and from semi-automatic to intelligent,and put forward three suggestions to help Chinese patent medicine achieve the goal of improving quality,efficiency and green manufacturing in production.

Solution processed membrane-based wearable ZnO/graphene Schottky UV photodetectors with imaging application.

Flexible and wearable electrical devices have attracted extensive research attention in recent years. In the device fabrication process, the low-cost and compatibility with industrialized mass production are of great importance. Herein, membrane-based flexible photodetectors (PDs) based on Polyvinylidene Fluoride filter membrane with the structure of Ag nanowires (NWs)/ZnO NWs/graphene were fabricated by a full-solution method. The built-in electric field due to the ZnO/graphene Schottky junction is in favor of the separation and transport of photo-generated carriers, leading to enhanced device performance. The I light/I dark ratio was as high as ∼102, which is far superior to that of the reported ZnO-based fiber-shaped PDs. The PDs with remarkable flexibility can be easily attached to the human body and even can work steadily under serious bending conditions. Particularly, the photocurrent can keep 95% of the maximum value after the PD was bent 1000 times. In addition to the wearable applications, the membrane-based PD arrays can also be applied for imaging application.

Band offsets in new BN/BX (X = P, As, Sb) lateral heterostructures based on bond-orbital theory.

Identifying heterostructures with tunable band alignments remains a difficult challenge. Here, based on bond-orbital theory, we propose a series of new BN/BX (X = P, As, Sb) lateral heterostructures (LHS). Our first principles calculations reveal that the LHS interlines have a substantial impact on the electronic properties. Importantly, we start with the chemical concepts, such as bond length and strength as well as orbital overlap interaction, in an attempt to thoroughly investigate the electronic properties, namely the band offset, the band gap (Eg) and the state of the energy level. We demonstrate that the newly designed BN/BX LHS have profound implications for developing advanced optoelectronics, such as high-performance light-emitting diodes and lasers. Furthermore, the new BN/BX LHS designed from the chemical viewpoint can shed new light on overcoming the enormous hurdle of ineffective and laborious material design.

Metal Halide Perovskites: Synthesis, Ion Migration, and Application in Field-Effect Transistors.

The past several years have witnessed tremendous developments of metal halide perovskite (MHP)-based optoelectronics. Particularly, the intensive research of MHP-based light-emitting diodes, photodetectors, and solar cells could probably reform the optoelectronic semiconductor industry. In comparison, in spite of the large intrinsic charge carrier mobility of MHPs, the development of MHP-based field-effect transistors (MHP-FETs) is relatively slow, which is essentially due to the gate-field screening effect induced by the ion migration and accumulation in MHP-FETs. This work mainly aims to summarize the recent important work on MHP-FETs and propose solutions in terms of the development bottleneck of perovskite-based transistors, in an attempt to boost the research of MHP transistors further. First, the advantages and potential applications of MHP-FETs are briefly introduced, which is followed by a detailed description of the MHP crystalline structure and various material fabrication techniques. Afterward, MHP-FETs are discussed, including transistors based on hybrid organic-inorganic perovskites, all-inorganic perovskites, and lead-free perovskites.

DFT coupled with NEGF study of a promising two-dimensional channel material: black phosphorene-type GaTeCl.

A stable three-dimensional layered GaTeCl bulk counterpart is first known from experiment since 1980s. In this study, we propose a two-dimensional GaTeCl, the band structure of which has a tendency of intrinsic direct-to-indirect band gap transitions as a result of a decrease in the layer number, while the changes in the band gap value are minor. The GaTeCl monolayer possesses a wide indirect band gap of 3.06 eV and high hole mobility of up to 4710 cm2 V-1 s-1, which, intriguingly, can be converted into direct band-gap semiconductors under a slight tensile strain. The GaTeCl monolayer is calculated to have an ideal cleavage energy of about 32 meV per atom; therefore, the synthesis of GaTeCl monolayer through exfoliation of bulk GaTeCl is available. In this regard, we simulate a monolayer GaTeCl MOSFETs device based on first-principles method quantum transport approach. The underlying device performance could pave the way for it to be a promising candidate as a suitable FET channel material.

Boosting Two-Dimensional MoS2/CsPbBr3 Photodetectors via Enhanced Light Absorbance and Interfacial Carrier Separation.

Transition metal dichalcogenides (TMDs) are promising candidates for flexible optoelectronic devices because of their special structures and excellent properties, but the low optical absorption of the ultrathin layers greatly limits the generation of photocarriers and restricts the performance. Here, we integrate all-inorganic perovskite CsPbBr3 nanosheets with MoS2 atomic layers and take the advantage of the large absorption coefficient and high quantum efficiency of the perovskites, to achieve excellent performance of the TMD-based photodetectors. Significantly, the interfacial charge transfer from the CsPbBr3 to the MoS2 layer has been evidenced by the observed photoluminescence quenching and shortened decay time of the hybrid MoS2/CsPbBr3. Resultantly, such a hybrid MoS2/CsPbBr3 photodetector exhibits a high photoresponsivity of 4.4 A/W, an external quantum efficiency of 302%, and a detectivity of 2.5 × 1010 Jones because of the high efficient photoexcited carrier separation at the interface of MoS2 and CsPbBr3. The photoresponsivity of this hybrid device presents an improvement of 3 orders of magnitude compared with that of a MoS2 device without CsPbBr3. The response time of the device is also shortened from 65.2 to 0.72 ms after coupling with MoS2 layers. The combination of the all-inorganic perovskite layer with high photon absorption and the carrier transport TMD layer may pave the way for novel high-performance optoelectronic devices.

Enhancing Optoelectronic Properties of Low-Dimensional Halide Perovskite via Ultrasonic-Assisted Template Refinement.

Low-dimensional halide perovskite (HP) has triggered lots of research attention in recent years due to anisotropic optoelectronic/semiconducting properties and enhanced stability. High-quality low-dimensional HPs via controllable engineering are required to fulfill the encouraging promise for device applications. Here, we introduce, for the first time, postsynthetic ultrasonic-assisted refinement of two-dimensional homologous HPs (OA2PbBr4, OA is octadecylamine). The solution-prepared OA2PbBr4, either in the form of large-sized microcrystal or nanosheet, obtains significantly enhanced crystallinity after ultrasonic treatment. We further show that OA2PbBr4 nanosheets can be used as a template to construct low-dimensional CsPbBr3 with the size and morphology inherited. Importantly, we found the ultrasonic-treated OA2PbBr4 crystals, compared with pristine ones, lead to enhanced optoelectronic properties for the resultant low-dimensional CsPbBr3, as demonstrated by improved photodetection performances, including prolonged charge-carrier lifetime, improved photostability, increased external quantum yield/responsivity, and faster response speed. We believe this work provides novel engineering of low-dimensional HPs beyond the reach of straightforward synthesis.

Field-Effect Transistors Based on van-der-Waals-Grown and Dry-Transferred All-Inorganic Perovskite Ultrathin Platelets.

Nowadays, the research on perovskite transistors is still in its infancy, despite the fact that perovskite-based solar cells and light-emitting diodes have been widely investigated. Two major hurdles exist before obtaining reliable perovskite-based transistors: the processing difficulty for their sensitivity to polar solvents and unsatisfactory perovskite quality on the transistor platform. Here, for the first time, we report on high-performance all-inorganic perovskite FETs profiting from both van der Waals epitaxial boundary-free ultrathin single crystals and completely dry-processed transfer technique without chemical contaminant. These two crucial factors ensure the unprecedented high-quality perovskite channels. The achieved FET hole mobility and on-off ratio reach 0.32 cm2 V-1 s-1 and 6.7 × 103, respectively. Moreover, at the low temperature, the mobility and on-off ratio can be enhanced to be 1.04 cm2 V-1 s-1 and 1.3 × 104. This work could open the door for the FET applications based on perovskite single crystals.

Low-Voltage Photodetectors with High Responsivity Based on Solution-Processed Micrometer-Scale All-Inorganic Perovskite Nanoplatelets.

All-inorganic photodetectors based on scattered CsPbBr3 nanoplatelets with lateral dimension as large as 10 µm are fabricated, and the CsPbBr3 nanoplatelets are solution processed governed by a newly developed ion-exchange soldering mechanism. Under illumination of a 442 nm laser, the photoresponsivity of photodetectors based on these scattered CsPbBr3 nanoplatelets is as high as 34 A W-1 , which is the largest value reported from all-inorganic perovskite photodetectors with an external driven voltage as small as 1.5 V. Moreover, the rise and fall times are 0.6 and 0.9 ms, respectively, which are comparable to most of the state-of-the-art all-inorganic perovskite-based photodetectors. All the material synthesis and device characterization are conducted at room temperature in ambient air. This work demonstrates that the solution-processed large CsPbBr3 nanoplatelets are attractive candidates to be applied in low-voltage, low-cost, ultra highly integrated optoelectronic devices.

Dimensionality and Interface Engineering of 2D Homologous Perovskites for Boosted Charge-Carrier Transport and Photodetection Performances.

Two-dimensional (2D) homologous halide perovskite (HP) microcrystallines have emerged as a promising alternative light-sensitive material; however, the undesirable quantum confinement effect and severe interfacial charge-carrier scattering still hamper their applications in photodetectors (PDs). Here we propose a novel postsynthetic treatment to simultaneously solve both problems. 2D (OA)2FAn-1PbnBr3n+1 (OA and FA represent octadecylamine and formamidine) microplatelet film was immersed in solution containing FA+, leading to improvements in two aspects. First, the dimensionality of 2D HPs was increased through an exchange reaction between OA+ and FA+, which meliorates the quantum confinement effect and facilitates the separation of electrons and holes; second, the free-standing 2D HP microcrystallines were fused for promoted interdomain charge-carrier transport. The treated PDs achieved a 3600 and 4200% increase in external quantum yield and responsivity up to 7100% and 32 A/W, respectively, and the rise/decay time was shortened by two orders of magnitude to 0.25/1.45 ms.

[Impact of intensive insulin therapy on surgical critically ill patients].

OBJECTIVE: To evaluating the effect of different levels of blood glucose control on inflammatory response and prognosis of the patients in surgical intensive care unit (SICU). METHODS: One hundred and eighty-eight patients admitted to SICU were randomly divided into three groups, blood glucose were controlled by insulin infusion. Group A (75 cases): the mean blood glucose (MBG) was maintained at the level of 4.4 - 6.1 mmol/L. Group B (75 cases): MBG was maintained at the level of 6.7 - 8.3 mmol/L. Group C (38 cases): MBG was maintained at the level of 10.0 - 11.1 mmol/L. Blood glucose control was achieved with an effected computerized protocol. The outcome was evaluated by days in ICU, days to wean mechanical ventilation, infection, amount of red blood cell transfusion, hospital mortality and ICU cost. RESULTS: Compared with other groups, hypoglycemia (< 3.3 mmol/L) in Group A was significantly increased (P < 0.05). Compared with Group C, red blood cell transfusion and infection were significantly reduced in Group A and Group B (P < 0.05). Compared with Group C, days of mechanical ventilation and days in ICU in Group A were significantly reduced (P < 0.05). Hospital mortality and ICU cost were reduced in Group A compared with the other groups (P > 0.05). CONCLUSIONS: To maintain blood glucose in normal range with intensive insulin therapy has potential positive impact on SICU patients' outcome and can reduce days in ICU and ICU cost. Further correlation research is needed to determine the best levels of blood glucose in ICU patients.