The efficiency of electrocatalytic CO2 reduction (ECR) is largely governed by the adsorption of CO2, a step often accompanied by pre-activation via molecular bending and electron redistribution before the first electron transfer occurs. However, the explicit correlation between the extent of CO2 pre-activation and the resultant reaction performance remains elusive due to the lack of direct structural evidence. Herein, we employ two In-MOFs, FJU-350 and FJU-351, as crystalline model catalysts to visualize distinct CO2 pre-activation configurations and unravel their critical role in ECR. FJU-350 exhibits superior ECR performance with FEformate of 90.9% at -1.4 V (vs. RHE), outperforming FJU-351 (88.6% at -1.6 V). Single-crystal X-ray diffraction analyses indicate that this 200 mV efficiency gain is the consequence of their distinct structural microenvironments. FJU-350 features a polarized carboxyl-oxygen site, stabilizing a uniquely bent CO2 species (127.2°) via single-site interaction, indicative of pronounced pre-activation. Theoretical calculations confirm that the highly distorted configuration facilitates charge transfer and lowers the energy barrier. In contrast, FJU-351 lacks such a directed site, accommodating near-linear CO2 (≥153.3°) via delocalized π-interactions. This work reveals a correlation between the pre-activated CO2 configuration and its electroreduction performance, providing a strategic foundation for designing efficient catalysts through precise micro-environment engineering.

Electrocatalytic reduction of CO2 to high-value chemicals and fuels, such as formate, offers a promising route to achieve carbon neutrality and climate change mitigation. In this work, we report a counterion-induced amorphization strategy applied to anionic indium metal-organic frameworks (In-MOFs) aimed at strengthening the binding of desired intermediates for efficient CO2 electroreduction. In-TDC containing the small counterion Me2NH2+ undergoes facile cation exchange, triggering framework reconstruction into an amorphous phase (A-In(OH)x(CO3)y). The A-In(OH)x(CO3)y catalyst achieves a FEformate of 97.2% at -1.4 V vs. RHE and maintains ∼90% selectivity for 36 h, far surpassing the other anionic crystalline analogue In-TEA with the bulky counterion TEA+ as a structural "anchor" for resisting collapse. Experimental and theoretical studies indicated that the better performance of A-In(OH)x(CO3)y results from the strong orbital coupling between In p and O p of *OCHO, which not only lowers the free energy barrier for the conversion of *CO2 to *OCHO but also enhances the *OCHO binding. This work highlights counterion exchangeability as a powerful tool to unlock p-orbital activity for efficient CO2 electroreduction.

Two novel single-phase proton-electron dual-conductivity Ag-organic coordination polymers, FJU-223-Dpe and FJU-223-Bpy, were synthesized for electrochemical CO2 reduction (ECR). These polymers exhibit distinct coordination environments and have watery hydrogen-bonding network structures. FJU-223-Dpe, with Ag-N coordination, demonstrates higher electronegativity and richer water molecules than FJU-223-Bpy, which possesses mixed Ag-N, O coordination. The proton conductivity of FJU-223-Dpe is 3.40 x 10-8 Scm-1 (76 times higher than FJU-223-Bpy's 4.50 x 10-10 Scm-1) at 25 degrees C and 98% RH. Additionally, the electron conductivity of FJU-223-Dpe (4.82 x 10-10 S cm-1) surpasses that of FJU-223-Bpy (1.17 x 10-11 S cm-1) by a factor of 41 at 25 degrees C. Furthermore, FJU-223-Dpe achieved superior ECR performance with a faradaic efficiency for CO of 77.3% (vs 72.1% for FJU-223-Bpy). Theoretical calculations indicated that FJU-223-Dpe facilitates the *COOH intermediate formation, enhancing its activity. This work presents a strategic approach to augmenting the efficacy of ECR by modulating the metal coordination environment of single-phase dual conductivity architectures.

Methanation serves as a strategy for the comprehensive utilization of CO2, however, designing catalysts with superior low-temperature activity and sintering resistance remains a significant challenge. Oxygen vacancies can greatly influence the catalytic activity, thus constructing catalysts with abundant oxygen vacancies is crucial for high-performance CO2 methanation reaction. In this study, a defect engineering strategy was employed to synthesize 15Ni/CeO2-U catalyst. Based on the characterization results from Raman spectroscopy and quasi in-situ XPS, the 15Ni/CeO2-U catalyst possesses an exceptionally abundant oxygen vacancies compared to the 15Ni/ CeO2 catalyst. Additionally, the catalyst exhibited highly dispersed active sites, moderate metal-support interaction strength, and a smaller Ni nanoparticle size. These factors synergistically enhanced its performance in the low-temperature CO2 methanation reaction, achieving a CO2 conversion of 77.1 % at 200 degrees C, with selectivity and space-time yield for CH4 of 98.7 % and 204.0 mmol & sdot; g-cat1 & sdot;h-1, respectively. The results indicate that it is one of the best low-temperature CO2 methanation catalysts to date. Density functional theory (DFT) calculations and in-situ DRIFTS analysis revealed that the presence of oxygen vacancies facilitates the further hydrogenation of CO2 to methane via the HCOO* pathway. This work offers a worthy strategy to constructing high-performance catalysts suitable for low-temperature CO2 methanation.

The construction of the active site is pivotal in the design of highly efficient catalysts for heterogeneous catalysis. Notably, the synergy between the two active sites can substantially enhance the catalytic efficiency. Nonetheless, fabricating high-density dual active sites on the catalyst surface remains a significant challenge. In this study, the host-guest strategy was employed to construct a dual active site Mo2N@ZrO2 heterostructure catalyst, featuring a significant number of nitrogen sites and oxygen vacancies. The Mo2N@ZrO2 catalyst exhibited near-equilibrium conversion and 100% CO selectivity in a reverse water-gas shift reaction at 350 °C. Density functional theory (DFT) calculations and in situ diffuse reflection infrared Fourier transform (DRIFT) spectroscopy characterization indicate that oxygen vacancies on the Mo2N@ZrO2 catalyst dissociate CO2 into CO, while Mo2N promotes H2 to form NHx species by heterolytic dissociation. The formation of NHx facilitates the desorption of CO and inhibits the further hydrogenation of CO*. This synergistic effect of the dual active site significantly enhances catalytic performance. This strategy of constructing a dual active site offers valuable insights for developing efficient catalysts.

Electrocatalytic CO2 reduction (ECR) has emerged as one of the most promising strategies to alleviate the energy crisis and CO2 pollution, for which a wide variety of catalysts are under development. Metal-organic frameworks (MOFs) with clear and designable structures are an excellent platform for ECR. In this study, two isostructural N, O-coordinated Zn-MOFs, FJU-126-4F, and FJU-126-CH3, based on terephthalic acid ligand with different groups (one is & horbar;4F and the other is & horbar;CH3) on the benzene ring, have been constructed for ECR catalysts. Significantly, the different functional groups make the performance difference of ECR. The maximum Faraday efficiency of formate (FEformate) for FJU-126-4F is 60.5% with the partial current density of formate (j(formate)) of -19.35 mA cm(-2) at -1.47 V, while the optimum FEformate of FJU-126-CH3 is 50.2% with the j(formate) of -10.04 mA cm(-2) at -1.57 V. This work provides an insight into the rational design of MOF catalysts for ECR.

Although, electrons transfer plays an important role in achieving the electrocatalytic CO2 reduction reaction (CO2RR), it is scarce to regulate the electron transfer channels for enhancing the performance of CO2RR via rational design. Here, based on different solvothermal conditions, two metal-organic coordination polymers (MOCPs, Ag-MOCP-1 and Ag-MOCP-2) electrocatalyst for CO2RR were obtained by the same Ag ions and 5-phenyltetrazolium ligands. Single crystal X-ray diffraction showed Ag-MOCP-2 with intra-&inter-layer C-H center dot center dot center dot pi and pi center dot center dot center dot pi interactions, while Ag-MOCP-1 with intra-layer pi center dot center dot center dot pi interactions. The intra-&inter-layer pi interactions in Ag-MOCP-2 makes it show multi-dimensional electron transfer channels, which enable Ag-MOCP-2 with higher electron conductivities and lower band gap than Ag-MOCP-1. And the Faradaic efficiency of CO for Ag-MOCP-2 with 78.3 % is higher than that for Ag-MOCP-1 with 69.1 % at -1.08 V vs RHE, and the maximum difference can reach 22 % at -1.48 V vs RHE. Based on the same central metal and organic ligands of the two MOCPs, we believe that multi-dimensional electron transfer channels make a predominant contribution for improving CO2RR performance in this work.

Electrochemical reduction of CO2 to formate by metal-organic frameworks (MOFs) is one of the promising routes to mitigate greenhouse gas emissions in the energy conversion field. Herein, two new N,O-coordinated Zn-MOFs (FJU-127-CH3 and FJU-127-NH2) were constructed from 3-amino-1,2,4-triazole (ATRZ) with 2-methyl-tereph-thalic acid (BDC-CH3) or 2-amino-terephthalic acid (BDC-NH2) for electrochemical CO2 reduction reaction (CO2RR). Different from all the reported N-or O-coordinated Zn-MOFs catalysts with the main product of CO or CH4, the two N,O-coordinated Zn-MOFs exhibit specific selectivity and activity for formate with faradaic effi-ciency (FE) more than 60%. Especially, self-penetration FJU-127-CH3 possesses superior FEformate of 90.2% at-1.57 V vs. RHE in comparison with common pillared-layer FJU-127-NH2. This work proposes an effective strategy to alter the selectivity of electrocatalytic CO2RR.

Metal–organic frameworks (MOFs) have important research value in the field of electrochemical CO2 reduction reaction because of their rational design. Here, a new MOF-CH3 was prepared via a simple solvothermal method by using Zn as the metal center and 1,2,4-triazole and 2-methyl-terephthalic acid as ligands for electrocatalytic CO2 reduction. The single-crystal X-ray diffraction shows that MOF-CH3 is N, O-coordinated 3D columnar layer framework with intramolecular hydrogen-bonding interactions. The powder X-ray diffraction for MOF-CH3 displays the good crystallinity of 24 h in 0.5 mol L−1 KHCO3 electrolyte solution. The electrochemical CO2 reduction reaction tests indicate that the MOF could effectively convert CO2 to formate, and the highest Faradaic efficiency of formate (FEformate) is 76.5

Two single-phase MOCPs with different electron and proton conductivities were used for the electrocatalytic CO2RR.

Self-powered sensors have great application prospects in the field of analytic chemistry because they can determine analytes without inputting external electricity. In this work, Fe2O3 electrode with nanorod morphology was synthesized by chemical bath method, then a layer of Ni(OH)(2) was decorated on the surface of Fe2O3 nanorods via successive ion adsorption. Furthermore, a Ni(OH)2/Fe2O3-based photo fuel cell (PFC) was fabricated as a novel self-powered sensor. The produced maximum power density (P-max) of the sensor shows a linear relationship with glucose concentrations in the range of 0.05-0.25 mM with a sensitivity of 24.59 mu W cm(-2) mM(-1), which is much higher than that of bare Fe2O3-based self-powered sensor (only 3.53 mu W cm(-2) mM(-1)). The better performance achieved on the Ni(OH)(2)/Fe2O3-based sensor is because Ni(OH)(2) has high electrocatalytic activity for glucose oxidation and it can improve photo-generated charge inject efficiency (eta inj) to substrate. In addition, the sensor also possesses good selectivity, stability and applicability for glucose sensing. In a word, this work provides a non-enzymatic, simple-construction, costeffective and sustainable PFC based self-powered sensor, which may guide future designs for the determination of analytes and offer a new route for utilization of widespread solar energy. (C) 2022 Published by Elsevier B.V.

To lower CO2 emissions and address the current energy crisis, one of the most promising approaches that converting the captured CO2 into valuable chemicals and fuels via electrocatalysis is proposed recently. Metal‐organic frameworks (MOFs) as an emerging multifunctional material have been extensively designed for electrocatalytic reduction of CO2. In terms of chemical and structural properties, 2D MOFs have obvious superiority over 3D bulk MOFs. Specifically, the large porosity and ultrathin structure of the 2D materials contribute to exotic properties such as enhanced electrical conductivity and rapid mass transport during reactions, which are in favor of electrocatalysis. In this review, the design strategies of 2D MOFs are discussed. Then, the recent advances of MOFs and their derivative catalysts with unique 2D structures for CO2 reduction are introduced. These examples are expected to provide clues to rational design strategies and synthesis of high‐performance CO2 electroreduction, beyond the bulk MOFs.

This is the first example of research on the identification of 'Blue tears' and its effect on water quality. In view of the fascinating 'Blue tears' appearing in Pingtan Island from April to July in recent years, a survey on plankton and regular water quality was conducted in Pingtan related sea areas all throughout the year 2018. It showed that plankton increased sharply during the bloom of 'Blue tears' in May and June, and Noctiluca scintillans with bio-luminescence ability is one of the main dominant species, up to 50,700 cells.L-1 in May. Phytoplankton availability largely determined the bloom of N. scintillans. Different from the reported work that Noctiluca scintillans may cause the sea water to deteriorate, the assimilative capacity of the coastal waters in Pingtan Island holds good. The growth and disappearing process of N. scintillans was also proposed.

可再生能源供应方案包括析氢反应(HER)、析氧反应(OER)、氧还原反应(ORR)和二氧化碳还原反应(CO2RR)等多种反应,电催化剂对这些反应至关重要.到目前为止,已有一系列导电金属有机骨架材料(MOFs)作为与能源相关电催化电极材料的报道.本文从提高MOFs导电能力和对产物的选择性、增强MOFs的化学稳定性及增加MOFs的反应活性位点等方面介绍了导电MOFs作为电催化剂的设计策略,重点综述了其在能源转化涉及的HER、OER、ORR以及CO2RR方面的应用,并从材料制备和应用需求角度出发,对高性能导电MOFs材料在电催化领域所面临的挑战和前景进行了展望.

利用溶剂热法合成了两例同构金属-有机框架(MOFs)化合物(FJU-40-H与FJU-40-NH2),进行X射线粉末衍射及红外分析,探究了两例MOFs在不同溶剂分子、 不同金属盐溶液和不同pH值溶液中的荧光性质.结果表明:羧酸配体上有无—NH2的存在对MOFs的荧光性能有明显的影响,在水体系中,FJU-40-NH2的荧光性能大大优于FJU-40-H.实验还发现:尽管Fe3+对该同构MOFs的荧光都有明显的淬灭作用,然而,利用FJU-40-NH2的荧光淬灭效应可实现对Fe3+的传感检测,而FJU-40-H则不适宜.同构MOFs配体官能团的不同可导致其荧光性能的差异,这可为高性能传感器的构建提供思路.

Measurement of phosphorus is of great significance because it is a key element responsible for eutrophication in water environment. More efforts have been devoted to sensor-based detection of phosphate (P(V)), while few reports on that of phosphite (P(III)) are available due to the interferences from phosphate and/or other species. Here we synthesized UiO-66/graphene oxide (GO) composites and first observed that the cooperative utilization of UiO-66 and GO may provide a promising strategy to improve the electrochemical performances of MOF hybrid materials for effective detection of phosphite (P(III)) in phosphate (P(V)) buffer solutions (PBS). The current value of the oxidation peak is proportional to the phosphite concentration over the range of 10 mu mol L-1- 500 mu mol L-1, and the limit of detection is 0.33 mu mol L-1(S/N=3) with the lowest value among the reported works.

The nanocomposites Eu2O3@[Zn2(bdc)2dabco] (ZBDh) synthesized by PLA in a flowing liquid can be used for the detection of methanol in fluorescence sensing.

This work reports the metal organic frameworks composite Eu2O3@[Zn2(1,4-ndc)2dabco] synthesized by pulsed laser ablation in flowing liquid. Powder X-ray Diffraction (PXRD) and SEM were used to characterize its structure and morphology. The results show that the Eu2O3 nanoparticles with the average particle size of 3.08 nm are uniformly distributed among the crystal and the BET specific surface area of the composite Eu2O3@[Zn2(1,4-ndc)2dabco] is 1087 m2/g. At 296 K, the adsorption capacities of C2H2 on composite are up to 117.3 cm3/g, which is larger than that of the compound [Zn2(1,4-ndc)2dabco]. The C2H6/CH4 selectivity of the composite Eu2O3@[Zn2(1,4-ndc)2dabco] is 25.9 and much higher than that of some familiar MOFs materials. Moreover, the composite Eu2O3@[Zn2(1,4-ndc)2dabco] can emit very intense characteristic fluorescence at 613 nm of Eu3+ ion under ultraviolet radiation and can be used for detecting of fatty alcohols with different branch chains in fluorescence sensing because of its fluorescence intensity at 613 nm is sensitive to fatty alcohol with different carbon chains. The luminescence based sensing mechanism of the composite Eu2O3@[Zn2(1,4-ndc)2dabco] was discussed.

It very important to be able to efficiently detect hydrazine hydrate in an aqueous medium due to its high toxicity. Here, we have proposed a new idea: to construct a sensor for the rapid determination of hydrazine hydrate based on the nano-CuO derived by controlled pyrolysis of HKUST-1 [Cu3(BTC)2(H2O)3]. The as-prepared CuO at 400 °C possesses a uniform appearance with nano-structure via SEM images, and the nano-CuO-400 has exhibited excellent electrocatalytic activity towards hydrazine oxidation. Amperometric i-t curves shows the peak current as linearly proportional to the hydrazine concentration within 1.98–169.3 μmol L−1 and 232–2096 μmol L−1 with the detection limit of 2.55 × 10−8 mol L−1 and 7.01 × 10−8 mol L−1, respectively. Moreover, the sensor constructed in the experiment shows good selectivities, and it is feasible to determining actual water samples.

Here we synthesized two new isostructural MOFs (FJU-82-Co/FJU-82-Zn) and first observed that tuning of the proton conductivity may provide an effective strategy to improve the electrocatalytic OER perfomances of isostructural crystalline MOF materials. The conductivity value for FJU-82-Co is 7.40 × 10-5 S cm-1, which is 127-fold that for FJU-82-Zn with 5.80 × 10-7 S cm-1 at 60 °C and 98% RH, while the overpotential of FJU-82-Co is 0.57 V at 1 mA cm-2, which is better than that of FJU-82-Zn with 1.17 V.