Search

Abstract Metal–organic frameworks (MOFs) are a class of promising nanomaterials for atmospheric water harvesting (AWH), especially in arid remote areas. However, several challenges are still faced for practical applications because of the dissatisfied water adsorption/desorption properties in terms of the capability, kinetics, and stability. Herein, we report the facile synthesis of a nano‐sized octahedral nitrogen‐modified MOF‐801 that exhibits superior solar‐powered AWH performance using a custom‐made device, with a state‐of‐the‐art water harvesting ability up to 4.64LH2OkgMOFs−1 from air upon 12‐h test under a relative humidity (RH) of 30% and simulated sunlight irradiation. The nitrogen‐modified MOF‐801 with rapid sorption–desorption kinetics, uptakes 0.29gH2OgMOFs‐1 of water at 30% RH within 30 min and releases 90% of the captured water within 10 min under 1‐sun illumination. The success relies on N‐doping‐induced mixed‐linkers in the form of 2,3‐diaminobutanedioic acid and fumaric acid in the unique pore structures of the MOFs for rapid and high‐capacity water capture. The N‐doped MOF‐801 with water uptake capacity, fast adsorption kinetics, and cycle stability sheds light on the practical use of MOFs for effective solar‐powered water harvesting from droughty air.

Abstract In order to treat dyes in the wastewater of the printing industry and to reutilize walnut shell (WS) waste generate economic benefits, supercritical carbon dioxide (SC-CO2) pretreatment technology was developed to prepare porous biochar as a precursor for adsorption material. Orthogonal experiments were conducted at the temperatures of 200, 300, and 400 ℃ with durations of 20, 40, and 60 min, and a control group was set up using N2 pretreatment. Then, KOH activation was employed to prepare biochar adsorption material. The biochars were analyzed and characterized using TGA, BET, SEM, FT-IR, and XRD, and the liquid and gas phase products of the pretreatment process were analyzed semi-quantitatively and quantitatively using GC–MS and gas chromatography. Methylene blue (MB) dye was selected as an indicator to measure the adsorption capacity of biochar, and adsorption kinetics were analyzed based on the data. The results indicate that pretreatment with SC-CO2 effectively enhanced the performance and yield of the activated carbon. The highest specific surface area increased by 18%, and the maximum adsorption of MB increased by 23% compared to the N2 control group. The yield increased by 8–262% and the specific surface area increased by 50–192% compared to the direct activation of walnut shell (WS). During the pretreatment processes for the preparation of biochar adsorption material with the best specific surface area, phenol-enriched bio-oil was produced as a by-product which has economic value. Graphical Abstract

Carbon dioxide (CO2) is one of the main factors contributing to the greenhouse effect. The dependence on fossil fuels has led to increasing levels of carbon dioxide in the atmosphere every year. And it is far from enough to solve the climate problem by reducing the consumption of fossil fuels to cut down carbon dioxide emissions. In recent years, a series of researches on Carbon Capture, Utilization and Storage (CCUS) have been carried out in various countries around the world. CO2 is a nontoxic, tasteless and stable gas at normal temperature. However, when it reaches supercritical state after rising temperature and pressure, it has the characteristics of low viscosity, high diffusivity and high density, and is widely used in green, pollution-free and efficient development technology. Because of these unique properties, supercritical carbon dioxide (sCO2) has attracted more and more attention from researchers. sCO2 has been widely used in many aspects by virtue of its high solubility and easy compression. Different from previous reviews which only introduced the application of sCO2 property, this paper introduces the current research status of the application of the thermodynamic property of carbon dioxide in extraction, dyeing, pharmaceutical, power generation, heat transfer and exploitation of unconventional oil and gas, and mainly analyzes each application in detail from the aspects of working mechanism and improving working efficiency. Finally, the research direction and problems needed to be solved for the application of CO2 thermal physics are proposed, which pave the way for other new applications.

The separation and transport of photogenerated carriers is regarded as a curial factor in photocatalytic H2 production. As known in solar cells and photoelectron-chemistry, to strengthen the electron conduction for effective utilization of carriers, the electron transport material (ETM) is widely applied. Herein, inspired by the function of ETM, we adopted barium stannate (BaSnO3, labeled as BSO) as an excellent ETM which had the merits of high electron mobility, suitable conduction band position and simple preparation, to adjust the carrier kinetics of dye Eosin Y (EY)-sensitized photocatalytic system. Detailly, the photocatalytic system with the spatial separation sites of photogenerated carriers excitation and water reduction reaction was elaborately constructed, that was, dye EY-sensitized BSO (EY/BSO) for photocatalytic H2 production. The photocatalytic H2-production rate of EY/BSO (257 μmol·h−1·gEY−1) in the absence of noble metals was 28.6 times higher than that of single EY (∼9 μmol·h−1·gEY−1) under visible-light irradiation. With systematic and comprehensive characterizations, the formed electron transport channel by the bidentate bridging of EY on BSO could accelerate the transfer of photogenerated electrons from EY to BSO, promoting the effective separation of photogenerated carriers for the enhanced photocatalytic performance. Moreover, the water reduction reaction for H2 production proceeded on the surface of BSO that acted as the H2-evolution cocatalyst, avoiding the use of high-cost noble metals. Furthermore, based on the well-proved ETM-based concept in the EY/BSO system, La-doped BaSnO3 (LBSO) with better electron transport ability was adopted to construct EY/LBSO system (344 μmol·h−1·gEY−1) which showed better photocatalytic activity than EY/BSO.

In the ZINC20 database, with the aid of maximum substructure searches, common substructures were obtained from molecules with high-strain-energy and combustion heat values, and further provided domain knowledge on how to design high-energy-density hydrocarbon (HEDH) fuels. Notably, quadricyclane and syntin could be topologically assembled through these substructures, and the corresponding assembled schemes guided the design of 20 fuel molecules (ZD-1 to ZD-20). The fuel properties of the molecules were evaluated by using group-contribution methods and density functional theory (DFT) calculations, where ZD-6 stood out due to the high volumetric net heat of combustion, high specific impulse, low melting point, and acceptable flash point. Based on the neural network model for evaluating the synthetic complexity (SCScore), the estimated value of ZD-6 was close to that of syntin, indicating that the synthetic complexity of ZD-6 was comparable to that of syntin. This work not only provides ZD-6 as a potential HEDH fuel, but also illustrates the superiority of learning design strategies from the data in increasing the understanding of structure and performance relationships and accelerating the development of novel HEDH fuels.

With the rising concerns on environmental pollution and emission reduction, plastic waste disposal draws great attention from governors and scientists. Instead of landfilling and incineration, chemical treatments are considered less polluting and resources recovering. Hydrothermal processing is considered a prospective technology for this issue. To regulate the conversion process and improve efficiency, a key step is to know the dominant stages and clarify the controlled part of the reaction. However, there is very limited number of researches on the visualized exhibition of this process. In this paper, a hydrothermal process visualization measure is adopted, to intuitionally demonstrate the whole conversion process. Polyoxymethylene (POM) spheres are employed as the feedstock in this experiment. A fixed-focus camera records the plastic sphere particle undergoing three stages of heated, swelling and dissolution, under hydrothermal condition. At the heated stage, the solid sphere becomes transparent, then during the swelling stage, the transparent sphere expands to around 130 % of the original size (sectional area), finally the expanded sphere is dissolved into fragments dispersing in the water. During the hydrothermal conversion, the carbon component of the plastic sphere immigrated into the aqueous phase, carbon recovery rate of the process reached as high as 90 %. The visualized results well demonstrate the physical and chemical transition of hydrothermal process, which would be a promising direction for future study.

The bistatic global navigation satellite system’s (GNSS) signal reflection technology has become an effective means of space-based sea surface wind field retrieval and height retrieval. By adopting a wider signal bandwidth, a higher pulse-limited footprint resolution can be achieved. However, for the GNSS-Reflectometry (GNSS-R) system, its signal bandwidth is affected by the signal bandwidth of the GNSS satellite, which limits the further improvement of the pulse-limited footprint resolution. This article proposes a method based on the novel signal bandwidth joint principle to improve the resolution of GNSS-R pulse-limited footprints. Firstly, currently in-orbit GNSS-R satellites use the traditional single frequency band (TSFB) method, which is limited by the GNSS satellite’s signals and has a theoretical upper limit on its signal bandwidth. In response to this issue, this article proposes the novel joint bandwidth (NJBW) method (Galileo E5a and E5b signals) based on the auto-correlation function (ACF) signal ambiguity theory. The NJBW method reduces the main lobe width of the ACF of the GNSS-R signal by jointly processing the signals of E5a and E5b frequency bands, thus improving the pulse-limit footprint resolution of GNSS-R. Secondly, in order to verify the improvement effect of the novel joint bandwidth method on the pulse-limited footprint resolution of GNSS-R, this paper designs and fabricates an NJBW antenna verification prototype for the joint Galileo E5a and E5b frequency band and tests it in a microwave anechoic chamber. The test results indicate that the radio frequency (RF) bandwidth of the NJBW antenna validation prototype can cover both the frequency bands of E5a and E5b, making it suitable for use as the NJBW method for the GNSS-R receiving antenna. The bandwidth test values of the NJBW antenna validation prototype are consistent with the design values, which verifies the correctness of the NJBW antenna design model and further proves the feasibility of the NJBW method. Thirdly, based on the joint Galileo E5a and E5b frequency band signals, the NJBW method was applied to analyze the improvement effect of the pulse-limited footprint resolution. Compared to the TSFB method, the application of the NJBW method can increase the resolution of the GNSS-R pulse-limiting footprint by 1.73 times, which effectively improves the performance of the GNSS-R system. The NJBW method proposed in this article provides the theoretical method foundation and key technical support for sea surface wind field retrieval and height retrieval and the antenna design for the future high-precision and high pulse-limited footprint resolution GNSS-R sea surface wind field retrieval and height retrieval verification satellite.

Summary: The diffuse-type gastric cancer (DGC) constitutes a subgroup of gastric cancer with poor prognosis and no effective molecular therapies. Here, we report a phosphoproteomic landscape of DGC derived from 83 tumors together with their nearby tissues. Based on phosphorylation, DGC could be classified into three molecular subtypes with distinct overall survival (OS) and chemosensitivity. We identified 16 kinases whose activities were associated with poor OS. These activated kinases covered several cancer hallmark pathways, with the MTOR signaling network being the most frequently activated. We proposed a patient-specific strategy based on the hierarchy of clinically actionable kinases for prioritization of kinases for further clinical evaluation. Our global data analysis indicates that in addition to finding activated kinase pathways in DGC, large-scale phosphoproteomics could be used to classify DGCs into subtypes that are associated with distinct clinical outcomes as well as nomination of kinase targets that may be inhibited for cancer treatments. : Biological Sciences; Cancer Systems Biology; Proteomics; Systems Biology Subject Areas: Biological Sciences, Cancer Systems Biology, Proteomics, Systems Biology

Poly (ADP-ribose) polymerase (PARP) inhibitor olaparib selectively kills cancer cells with BRCA-deficiency and is approved for BRCA-mutated breast, ovarian and pancreatic cancers by FDA. However, phase III study of olaparib failed to show a significant improvement in overall survival in patients with gastric cancer (GC). To discover an effective biomarker for GC patient-selection in olaparib treatment, we analyzed proteomic profiling of 12 GC cell lines. MTA2 was identified to confer sensitivity to olaparib by aggravating olaparib-induced replication stress in cancer cells. Mechanistically, we applied Cleavage Under Targets and Tagmentation assay to find that MTA2 proteins preferentially bind regions of replication origin-associated DNA sequences, which could be enhanced by olaparib treatment. Furthermore, MTA2 was validated here to render cancer cells susceptible to combination of olaparib with ATR inhibitor AZD6738. In general, our study identified MTA2 as a potential biomarker for olaparib sensitivity by aggravating olaparib-induced replication stress.

Two types of graphite/diamond (GD) particles with different ash content was applied to prepare new electroconductive polylactide (PLA)-based nanocomposites. Four samples of nanocomposites for each type of GD particles with mass fraction 0.01, 0.05, 0.10, and 0.15 were prepared via an easily scalable method—melt blending. The samples were subjected to the studies of electrical properties via broadband dielectric spectroscopy. The results indicated up to eight orders of magnitude improvement in the electrical conductivity and electrical permittivity of the most loaded nanocomposites, in reference to the neat PLA. Additionally, the influence of ash content on the electrical conductivity of the nanocomposites revealed that technologically less-demanding fillers, i.e., of higher ash content, were the most beneficial in the light of nanofiller dispersibility and the final properties.

Photocatalytic hydrogen production from water has been considered to be one of the most promising solar-to-hydrogen conversion technologies. In the last decade, various functionalized nanostructures were designed to address the primary requirements for an efficient photocatalytic generation of hydrogen by using solar energy: visible-light activity, chemical stability, appropriate band-edge characteristics, and potential for low-cost fabrication. Our aim is to present a short review of our recent attempts that center on the above requirements. We begin with a brief introduction of photocatalysts coupling two or more semiconductors, followed by a further discussion of the heterostructures with improved matching of both band structures and crystal lattices. We then elaborate on the heterostructure design of the targeted materials from macroscopic regulation of compositions and phases, to the more precise control at the nanoscale, i.e., materials with the same compositions but different phases with certain band alignment. We conclude this review with perspectives on nanostructure design that might direct future research of this technology.

In recent years, solar-powered photocatalytic water splitting for hydrogen production has drawn great attention as a method to supply clean energy and reduce environmental pollution. This approach, driven by solar energy to synthesize hydrogen gas, is completely renewable and can be used to power hydrogen fuel cells to effectively solve the global energy problem, while only releasing environmentally benign water. Accordingly, popularizing this subject and educating students with the knowledge of this powerful technology are urgently needed. In this paper, Pt-loaded commercial titanium dioxide (P25) is used as the photocatalyst to explore the process of photocatalytic hydrogen evolution. A simple experimental demonstration is presented, integrating photocatalytic hydrogen production with a hydrogen fuel cell system in chemistry class. This experiment is suitable for use with undergraduate students as a systematic and basic laboratory experience or as a demonstration for primary/middle/high school students to stimulate their research interests in field of renewable energy. The principles and reaction mechanisms involved in both photocatalytic water splitting and hydrogen fuel cell operation, as well as the experimental design to link photocatalysis with fuel cells, are systematically discussed.