Membranes with Fast and Selective Gas‐Transport Channels of Laminar Graphene Oxide for Efficient CO2 Capture

Graphene oxide (GO) nanosheets were engineered to be assembled into laminar structures having fast and selective transport channels for gas separation. With molecular‐sieving interlayer spaces and straight diffusion pathways, the GO laminates endowed as‐prepared membranes with excellent preferential CO₂ permeation performance (CO₂ permeability: 100 Barrer, CO₂/N₂ selectivity: 91) and extraordinary operational stability (>6000 min), which are attractive for implementation of practical CO₂ capture.     

还原氧化石墨烯/金纳米修饰电极在新冠病毒检测中的应用

研究使用电化学沉积法在丝网印刷碳电极表面制备了还原氧化石墨烯和金纳米颗粒,构建了一种用于新冠病毒检测的石墨烯电化学传感器。通过扫描电子显微镜(SEM)和相应的电化学方法对纳米复合材料在电极表面的成功修饰进行了表征分析。并采用差分脉冲伏安法对传感器的性能进行检测,实验构建的电化学传感器具有良好的灵敏度,该传感器检线性范围为10_-10^-10_-6^mol/L,具有良好的重复性和特异性。     

Loading Nickel Atoms on GDY for Efficient CO2 Fixation and Conversion

Carbon dioxide(CO₂) is an important and valuable C1 resource for the synthesis of numerous of value-added products. However, efficient fixation and conversion of CO₂ into organic carbonates under mild conditions remain great challenges. Herein, graphdiyne(GDY)-based nickel atomic catalysts(Ni⁰/GDYs) were synthesized through a facile in-situ reduction method. Experimental results showed that the obtained Ni⁰/GDY had outstanding catalytic performances for converting CO₂ into cyclic carbonates with a high reaction conversion(99%) and reaction selectivity(ca. 100%) at 80℃ and under 1 atm(1 atm=101325 Pa). Specially, the activation energy (E_a) value for the Ni⁰/GDY is 37.05 kJ/mol, lower than those of reported catalysts. The reaction mechanism was next carefully analyzed by using density functional theory(DFT) calculations. Such an excellent catalytic property could be mainly attributed to the high dispersion of active sites on the Ni⁰/GDY, and the unique incomplete charge transfer properties of GDY-based zero-valent metallic catalysts.     

Radiolytic Approach for Efficient,Selective and Catalyst-free CO2 Conversion at Room Temperature

The present study proposes a new approach for direct CO₂ conversion using primary radicals from water irradiation. In order to ensure reduction of CO₂ into CO₂^−. by all the primary radiation-induced water radicals, we use formate ions to scavenge simultaneously the parent oxidizing radicals H^. and OH^. producing the same transient CO₂^−. radicals. Conditions are optimized to obtain the highest conversion yield of CO₂. The goal is achieved under mild conditions of room temperature, neutral pH and 1 atm of CO₂ pressure. All the available radicals are exploited for selectively converting CO₂ into oxalate that is accompanied by H₂ evolution. The mechanism presented accounts for the results and also sheds light on the data in the literature. The radiolytic approach is a mild and scalable route of direct CO₂ capture at the source in industry and the products, oxalate salt and H₂, can be easily separated.     

Graphene Oxide Supported Molybdenum Cluster: First Heterogenized Homogeneous Catalyst for the Synthesis of Dimethylcarbonate from CO2 and Methanol

The octahedral molybdenum cluster‐based compound, Cs₂Mo₆Brⁱ₈Br^a₆ was immobilized on graphene oxide (GO) by using a facile approach. High resolution transmission electron microscopy results revealed that molybdenum clusters were uniformly distributed on the GO nanosheets. Cs₂Mo₆Brⁱ₈Br^a₆ was attached to the GO support via chemical interaction between apical ligands of Mo₆Brⁱ₈Br^a₆ cluster units and oxygen functionalities of GO, as revealed by XPS studies. The developed material was used for the synthesis of dimethyl carbonate by reduction of carbon dioxide. The synthesized catalyst, that is, GO–Cs₂Mo₆Brⁱ₈Br^a_x, exhibited higher catalytic efficiency than its homogeneous analogue without using dehydrating agent. The catalyst was found to be efficiently recyclable without significant loss of catalytic activity.     

Chemical Modification of Graphene Oxide through Diazonium Chemistry and Its Influence on the Structure–Property Relationships of Graphene Oxide–Iron Oxide Nanocomposites

4‐Carboxyphenyl groups are covalently grafted onto graphene oxide via diazonium chemistry for studying their role on the adsorption of iron oxide nanoparticles. The nanoparticles are deposited via a novel phase‐transfer approach involving specific interactions at the interface between two immiscible solvents. The increased density and the homogeneous distribution of surface carboxyl moieties enable the preparation of a nanocomposite with improved iron oxide distribution and loading. Structure‐properties relationships are investigated by analysing the electrochemical properties of the nanocomposites, which are regarded as promising active materials for application in supercapacitors. It is demonstrated that the nature of the interactions between the components similarly affects the overall electrochemical performances of the nanocomposites and the structure of the materials.     

Bismuth-Oxide-Decorated Graphene Oxide Hybrids for Catalytic and Electrocatalytic Reduction of CO2

Global warming challenges are fueling the demand to develop an efficient catalytic system for the reduction of CO₂, which would contribute significantly to the control of climate change. Herein, as-synthesized bismuthoxide-decorated graphene oxide (Bi₂O₃@GO) was used as an electro/thermal catalyst for CO₂ reduction. Bi₂O₃@GO is found to be distributed uniformly, as confirmed by scanning electron and transmission electron microscopic analysis. The X-ray diffraction (XRD) pattern shows that the Bi₂O₃ has a β-phase with 23.4 m² g⁻¹ BET surface area. Significantly, the D and G bands from Raman spectroscopic analysis and their intensity ratio (I_D/I_G) reveal the increment in defective sites on GO after surface decoration. X-ray photoelectron spectroscopic (XPS) analysis shows clear signals for Bi, C, and O, along with their oxidation states. An ultra-low onset potential (−0.534 V vs. RHE) for the reduction of CO₂ on Bi₂O₃@GO is achieved. Furthermore, potential-dependent (−0.534, −0.734, and −0.934 vs. RHE) bulk electrolysis of CO₂ to formate provides Faradaic efficiencies (FE) of approximately 39.72, 61.48, and 83.00 %, respectively. Additionally, in time-dependent electrolysis at a potential of −0.934 versus RHE for 3 and 5 h, the observed FEs are around 84.20 % and 87.17 % respectively. This catalyst is also used for the thermal reduction of CO₂ to formate. It is shown that the thermal reduction provides a path for industrial applications, as this catalyst converts a large amount of CO₂ to formate (10 mm ).     

Reactive Graphene Oxide Nanosheets: A Versatile Platform for the Fabrication of Graphene Oxide–Biomolecule/Polymer Nanohybrids

Graphene oxide (GO) nanosheets can be functionalized with reactive pentafluorophenyl ester via esterification of the carboxylic groups. The resulting reactive GO nanosheets provide a versatile platform for grafting of amino‐containing polymers or biomolecules via ester–amine coupling. Coupling of poly[(9,9‐dioctylfluorene)‐alt‐(4‐amino‐phenylcarbazole)] (PFCz‐NH₂), amino‐terminated hyperbranched polyglycerol (HPG‐NH₂), and lysozyme (Lyz) was illustrated. The Al/GO‐g‐PFCz/ITO sandwich thin‐film device exhibits bistable electrical switching and rewritable memory effects. The GO‐g‐Lyz nanohybrids exhibit high bactericidal efficacy against S. aureus and E. coli, while the GO‐g‐HPG nanohybrids exhibit reduced cytotoxicity toward 3T3 fibroblasts.     

卟啉金属-有机框架在二氧化碳捕获与转化上的应用研究

近几十年来，气候变暖、海平面上升等全球性气候问题日益严重，对人们赖以生存的自然环境造成了巨大的威胁.为了缓解并最终解决温室效应，多年来人们一直着手研究以二氧化碳（CO₂）为主的温室气体的处理方法.CO₂捕获和转化是一项新的技术，将捕获得到的CO₂直接转化成甲酸、甲醇、甲烷等小分子有机物或药物中间体等高附加值的化合物.卟啉金属-有机框架（Porphyrin Metal-Organic Frameworks，PMOFs）是一种基于卟啉配体和金属节点的多孔配位框架材料.卟啉配体具有良好热稳定性、化学稳定性以及优异独特的光学性能，结合MOFs框架的多孔性带来的对CO₂等气体分子的良好吸附性，使得PMOFs在CO₂捕获与转化上具有巨大的潜力.首先，介绍了PMOFs合成中常用的构筑策略，包括拓扑导向、柱层策略以及金属-有机笼策略.然后，根据次级结构基元对常见的PMOFs结构进行系统分类，包括基于低价态金属离子、桨轮状M₂（COO）₄、金属-氧无限长链和硬酸金属-氧簇四类，叙述了各类PMOFs的结构特性和稳定性.随后，通过一些代表性的实例分类总结了PMOFs在CO₂捕获与转化上的应用，包括CO₂的捕获、环加成反应、光催化反应和电催化反应.最后，总结了PMOFs在四大类应用中具有的优势与挑战，并展望了PMOFs在CO₂捕获与转化中的机遇和发展前景.     

Synergistic Interplay of Dual-Active-Sites on Metallic Ni-MOFs Loaded with Pt for Thermal-Photocatalytic Conversion of Atmospheric CO2 under Infrared Light Irradiation

Infrared light driven photocatalytic reduction of atmospheric CO₂ is challenging due to the ultralow concentration of CO₂ (0.04 %) and the low energy of infrared light. Herein, we develop a metallic nickel-based metal–organic framework loaded with Pt (Pt/Ni-MOF), which shows excellent activity for thermal-photocatalytic conversion of atmospheric CO₂ with H₂ even under infrared light irradiation. The open Ni sites are beneficial to capture and activate atmospheric CO₂, while the photogenerated electrons dominate H₂ dissociation on the Pt sites. Simultaneously, thermal energy results in spilling of the dissociated H₂ to Ni sites, where the adsorbed CO₂ is thermally reduced to CO and CH₄. The synergistic interplay of dual-active-sites renders Pt/Ni-MOF a record efficiency of 9.57 % at 940 nm for converting atmospheric CO₂, enables the procurement of CO₂ to be independent of the emission sources, and improves the energy efficiency for trace CO₂ conversion by eliminating the capture media regeneration and molecular CO₂ release.     

Central Doping of a Foreign Atom into the Silver Cluster for Catalytic Conversion of CO2 toward C−C Bond Formation

Clusters with an exact number of atoms are of particular interest in catalysis. Their catalytic behaviors can be potentially altered with the addition or removal of a single atom. Now the effects of doping with a single foreign atom (Au, Pd, and Pt) into the core of an Ag cluster with 25 atoms on the catalytic properties are explored, where the foreign atom is protected by 24 Ag atoms (Au@Ag₂₄, Pd@Ag₂₄, and Pt@Ag₂₄). The central doping of a single atom into the Ag₂₅ cluster has a substantial influence on the catalytic performance in the carboxylation reaction of CO₂ with terminal alkyne through C?C bond formation to produce propiolic acid. These studies reveal that the catalytic properties of the cluster catalysts can be dramatically changed with the subtle alteration by a single atom away from the active sites.     

Nitrogen‐Doped Graphene Quantum Dots Enhance the Activity of Bi2O3 Nanosheets for Electrochemical Reduction of CO2 in a Wide Negative Potential Region

Large numbers of catalysts have been developed for the electrochemical reduction of CO₂ to value‐added liquid fuels. However, it remains a challenge to maintain a high current efficiency in a wide negative potential range for achieving a high production rate of the target products. Herein, we report a 2D/0D composite catalyst composed of bismuth oxide nanosheets and nitrogen‐doped graphene quantum dots (Bi₂O₃‐NGQDs) for highly efficient electrochemical reduction of CO₂ to formate. Bi₂O₃‐NGQDs demonstrates a nearly 100 % formate Faraday efficiency (FE) at a moderate overpotential of 0.7 V with a good stability. Strikingly, Bi₂O₃‐NGQDs exhibit a high activity (average formate FE of 95.6 %) from ?0.9 V to ?1.2 V vs. RHE. Additionally, DFT calculations reveal that the origin of enhanced activity in this wide negative potential range can be attributed to the increased adsorption energy of CO₂(ads) and OCHO* intermediate after combination with NGQDs.     

Nitrogen-Doped Porous Carbon Materials Derived from Graphene Oxide/Melamine Resin Composites for CO2 Adsorption

CO₂ adsorption in porous carbon materials has attracted great interests for alleviating emission of post-combustion CO₂. In this work, a novel nitrogen-doped porous carbon material was fabricated by carbonizing the precursor of melamine-resorcinol-formaldehyde resin/graphene oxide (MR/GO) composites with KOH as the activation agent. Detailed characterization results revealed that the fabricated MR(0.25)/GO-500 porous carbon (0.25 represented the amount of GO added in wt.% and 500 denoted activation temperature in °C) had well-defined pore size distribution, high specific surface area (1264 m²·g⁻¹) and high nitrogen content (6.92 wt.%), which was mainly composed of the pyridinic-N and pyrrolic-N species. Batch adsorption experiments demonstrated that the fabricated MR(0.25)/GO-500 porous carbon delivered excellent CO₂ adsorption ability of 5.21 mmol·g⁻¹ at 298.15 K and 500 kPa, and such porous carbon also exhibited fast adsorption kinetics, high selectivity of CO₂/N₂ and good recyclability. With the inherent microstructure features of high surface area and abundant N adsorption sites species, the MR/GO-derived porous carbon materials offer a potentially promising adsorbent for practical CO₂ capture.     

Basic Catalytic Performance of Amino and Acylamide Functionalized Metal-organic Framework in the Synthesis of Chloropropene Carbonate from CO2 Under Atmospheric Pressure

In this work, a metal-organic framework with free standing basic groups(e. g., amino and acylamide groups) decorated in the pore wall was utilized to catalyze the CO₂ cycloaddition reaction and its basic properties were tested in Knoevenagel condensation reactions. The results reveal that the metal-organic framework(MOF) material has excellent catalytic activity and high repeatability for the synthesis of chloropropene carbonate from CO₂ and epichlorohydrin with no co-catalyst under mild reaction conditions, suggesting that it is a promising heteroge-neous catalyst for CO₂ cycloaddition reaction.     

CO_2响应石墨烯体系的制备及其性能研究

利用CO_2响应性的含芘聚合物(PNDV)作为分散剂,通过π-π共轭作用力成功附着在石墨烯表面,从而制得一种稳定的石墨烯分散体系。采用UV-Vis、IR、荧光光谱和透射电子显微镜对体系中石墨烯的分散性和CO_2响应性能进行表征。结果表明:PNDV可修饰在石墨烯表面,形成含芘聚合物和石墨烯的杂化体(PNDV-RGO),得到稳定均匀的石墨烯分散溶液。透射电镜显示石墨烯在体系中以单片层形式分布,最大宽度约1μm。在交替通入CO_2/N2后,PNDV-RGO杂化体表现出明显的分散/聚集现象。     

Electrochemical Simultaneous Sensing of Melatonin,Dopamine and Acetaminophen at Platinum Doped and Decorated Alpha Iron Oxide

Simultaneous sensing of dopamine (DA), acetaminophen (AP) and melatonin (MEL) was made by electrochemical method as the drugs melatonin and acetaminophen interact with dopamine in brain to induce neuro disorders. The glassy carbon electrode surface was modified with un‐doped α‐ Fe₂O₃, platinum doped Fe₂O₃ (dPtFe₂O₃), Pt decorated Fe₂O₃ (sPtFe₂O₃) and doped and decorated Fe₂O₃ (sdPtFe₂O₃) nano particles that are synthesized by co‐precipitation method in presence of polyethylene glycol for the first time. These particles were characterized using Ultra‐Violet Visible (UV‐Vis), scanning electron microscopy (SEM), X‐ray diffractometry (XRD), Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA) and electrochemical techniques. The sdPtFe₂O₃ showed the highest catalytic activity than the dPtFe₂O₃, sPtFe₂O₃ and un‐doped α‐ Fe₂O₃ with well separated voltammetric peaks for DA and AP in presence of MEL. This is attributed to higher surface hydration effects of the sdPtFe₂O₃, dPtFe₂O₃ and sPtFe₂O₃ than the un‐doped Fe₂O₃ which plays a vital role in enhancing the melatonin sensing in presence of dopamine and acetaminophen. Linear ranges and lowest detection limits for all three analytes were increased by 10 times for the sdPtFe₂O₃ compared to other Fe₂O₃ modified electrodes. The sensor is validated using commercially available pharmaceutical drugs used in therapeutics.     

Direct and Oriented Conversion of CO2 into Value-Added Aromatics

The oriented conversion of CO₂ into target high-value chemicals is an effective way to reduce carbon emissions, but still presents a challenge. In this communication, we report the oriented conversion of CO₂ into value-added aromatics, especially para-xylene, in a single pass by combining core–shell structured Zn-doped H-ZSM-5 (Zn-ZSM-5@SiO₂) and a Cr₂O₃ component. Through precise regulation of the acidity of Zn-ZSM-5@SiO₂, high para-xylene selectivity (38.7 % in the total products) at a CO₂ conversion of 22.1 % was achieved. Furthermore, a CO₂-assisted effect in the synthesis of aromatics during the tandem process has been clarified through a control experiment. The CO₂ reactant can act as a hydrogen acceptor to accelerate the dehydrogenation of alkenes, intermediates in the synthesis of aromatics, thereby increasing the driving force towards aromatics in the tandem reaction process.