Flow Channel with Recognition Corners in a Stable La-MOF for One-Step Ethylene Production.

Single-step ethylene (C2H4) production from acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) mixtures was realized via the strategy of a flow channel with recognition corners in MOF NTUniv-64. Both the uptake amounts and the enthalpy of adsorption (Qst) showed the same order of C2H2 > C2H6 > C2H4. Breakthrough testing also verified the above data and the C2H4 purification ability. Grand Canonical Monte Carlo (GCMC) simulations indicated that uneven corners could precisely detain C2H2 and C2H6, in which the C-H···π interaction distance between C2H2 (2.84 Å) and C2H6 (3.03 Å) and the framework was shorter than that of C2H4 (3.85 Å).

Fine Tuning Metal-Organic Frameworks with Halogen Functional Groups for Ethylene Purification.

One-step C2H4 purification from a mixture of C2H2/C2H4/C2H6 could be achieved by metal-organic framework (MOF) NTUniv-70 with an F-functional group. The selectivities of C2H4/C2H6 and C2H4/C2H2 of NTUnvi-70 based on ideal adsorbed solution theory were at least twice that of the original MOF platform, which was in line with the enthalpy of adsorption (Qst) and breakthrough testing. Grand canonical Monte Carlo simulations indicated that the C-H···F interactions played an important role in enhanced C2H4/C2H6 and C2H4/C2H2 adsorption selectivities.

Direct Ethylene Purification from a Four-Component Gas Mixture by a Microporous MOF with Aromatic Pore Surface and Carboxylates.

The single-step purification of ethylene (C2H4) from a mixture of carbon dioxide (CO2), acetylene (C2H2), ethylene (C2H4), and ethane (C2H6) was achieved through MOF Compound-1, where the aromatic pore surface and carboxylates selectively recognized C2H6 and CO2, respectively, resulting in a reversal of the adsorption orders for both gases (C2H6 > C2H4 and CO2 > C2H4). Breakthrough testing verified that the C2H4 purification ability could be enhanced 2.6 times after adding impure CO2. Grand Canonical Monte Carlo (GCMC) simulations demonstrate that there are interactions between CO2 and C2H6 molecules as well as between CO2 molecules themselves. These interactions contribute to the enhancement of the C2H4 purification ability upon the addition of CO2 and the increased adsorption of CO2.

Synergistic Lewis and Brønsted Acid Sites Promote OH* Formation and Enhance Formate Selectivity: Towards High-efficiency Glycerol Valorization.

As a sustainable valorization route, electrochemical glycerol oxidation reaction (GOR) involves in formation of key OH* and selective adsorption/cleavage of C-C(O) intermediates with multi-step electron transfer, thus suffering from high potential and poor formate selectivity for most non-noble-metal-based electrocatalysts. So, it remains challenging to understand the structure-property relationship as well as construct synergistic sites to realize high-activity and high-selectivity GOR. Herein, we successfully achieve dual-high performance with low potentials and superior formate selectivity for GOR by forming synergistic Lewis and Brønsted acid sites in Ni-alloyed Co-based spinel. The optimized NiCo oxide solid-acid electrocatalyst exhibits low reaction potential (1.219 V@10 mA/cm2) and high formate selectivity (94.0 %) toward GOR. In situ electrochemical impedance spectroscopy and pH-dependence measurements show that the Lewis acid centers could accelerate OH* production, while the Brønsted acid centers are proved to facilitate high-selectivity formation of formate. Theoretical calculations reveal that NiCo alloyed oxide shows appropriate d-band center, thus balancing adsorption/desorption of C-O intermediates. This study provides new insights into rationally designing solid-acid electrocatalysts for biomass electro-upcycling.

High-Efficiency CsPbI2Br Perovskite Solar Cells with over 83% Fill Factor by Synergistic Effects of a Multifunctional Additive.

All-inorganic CsPbI2Br with outstanding thermal stability and excellent photoelectric properties is considered as a promising candidate for photovoltaic applications. However, the efficiency of CsPbI2Br perovskite solar cells (PSCs) is still much lower than that of their organic-inorganic hybrid counterparts or CsPbI3-based devices. Herein, we obtained an optimized CsPbI2Br PSC (0.09 cm2) with a champion efficiency of 17.38% and a record fill factor of 83.6% by introducing potassium anthraquinone-1,8-disulfonate (DAD) in the precursor solution. The synergistic effect between the electronegative functional groups and K+ ions in the DAD structure can not only effectively regulate the crystallization growth process to improve the crystalline quality and stability of photo-active CsPbI2Br but also optimize the energy level alignment and passivate the defects to improve the carrier transport properties. The efficiency of the corresponding large-area device (5 cm × 5 cm with an active area of 19.25 cm2) reached 13.20%. Moreover, the optimized CsPbI2Br PSC exhibited negligible hysteresis and enhanced long-term storage stability as well as thermal stability. Our method produces more stable photo-active CsPbI2Br with excellent photoelectric properties for industrial applications or perovskite/silicon tandem cells.

Fine-Tuning MOFs with Amino Group for One-Step Ethylene Purification from the C2 Hydrocarbon Mixture.

Due to the similar kinetic diameters of C2H2, C2H4, and C2H6, one-step purification of C2H4 from a ternary C2H2/C2H4/C2H6 mixture by adsorption separation is still a challenge. Based on a C2H6-trapping platform and crystal engineering strategy, the N atom and amino group were introduced into NTUniv-58 and NTUniv-59, respectively. Gas adsorption testing of NTUniv-58 showed that both the C2H2 and C2H4 uptake capacities and the C2H2/C2H4 separation ability were boosted compared with the original platform. However, the C2H4 uptake value exceeds the C2H6 adsorption data. For NTUniv-59, the C2H2 uptake at low pressure increased and the C2H4 uptake decreased; thus, the C2H2/C2H4 selectivity was enhanced and the one-step purification of C2H4 from a ternary C2H2/C2H4/C2H6 mixture was realized, which was supported by the enthalpy of adsorption (Qst) and breakthrough testing. Grand canonical monte carlo (GCMC) simulation indicated that the preference for C2H2 over C2H4 originates from multiple hydrogen-bonding interactions between amino groups and C2H2 molecules.

Expanding MOF with Unexpanded Channel via Ketone Decorated Ligand for Ethylene Purification and Stability Enhancement.

The concept of an expanding MOF with unexpanded channel size was realized in MOF NTUniv-61 by the utilization of a ketone-functional-group-decorated semirigid ligand and pillar-layer platform. After this unusual expansion, the preferential C2H6 adsorption was preserved via the unchanged pore size, and the functional group was inserted into the MOF. Interestingly, the C2H2 uptake ability, C2H4 selective adsorption ability, and structural stability were obviously enhanced due to the incorporation of the ketone functional group, which were further verified by isosteric heats of adsorption (Qst), GCMC modeling, and breakthrough experiments.

Creating an Ethane Trap in a Ketone-Decorated MOF for One-Step Ethylene Separation from C2 Hydrocarbons.

One-step C2H4 purification from a mixture of C2H2/C2H4/C2H6 by physical adsorption separation was realized via creating an ethane trap in MOF NTUniv-63 by the utilization of a ketone-decorated semirigid ligand, which has further been verified by the breakthrough experiment, isosteric heats of adsorption (Qst), and Grand Canonical Monte Carlo (GCMC) modeling.

Multifunctional anthraquinone-sulfonic potassium salts passivate the buried interface for efficient and stable planar perovskite solar cells.

SnO2-based planar perovskite solar cells (PSCs) are considered as potential photovoltaic candidates due to their simple structures and cost-effective preparation processes. However, the extensive defects accumulated at the buried interface between perovskite and SnO2 greatly hinder the further improvement of PSC efficiency and stability. Herein, the potassium salt of anthraquinone-1,8-disulfonate (ASPS) is used as a novel multifunctional interfacial modifier to improve the carrier transport performance at the buried interface and optimize the quality of the upper perovskite light absorber layer (PVK) in PSCs. Owing to the synergistic effect of sulfonic acid groups, carbonyl groups and potassium ions in ASPS, the accumulated defects at the buried interface are passivated, the energy level arrangement of the interface is optimized, and the crystalline quality and optoelectronic properties of the PVK films are improved. As a result, the power conversion efficiency (PCE) improved significantly from 21.36% for the controlled device to 23.96% for the ASPS-modified device. Furthermore, the unencapsulated ASPS-modified device also exhibited better storage stability and thermal stability than the controlled device.

MOF Pillaring Method: Ligand-to-Ligand and Axial-to-Axial Cross-Linking of "Paddlewheels".

By shortening the previous shortest tetracarboxylate ligand, the first ligand-to-ligand and axial-to-axial pillaring method was realized in the prototype MOF NTUniv-56 (NTUniv = Nantong University), which exhibit a rare (2,4,6)-connected net with a new topology and interesting gas adsorption performance.

Formation of a Polar Flow Channel with Embedded Gas Recognition Pockets in a Yttrium-Based MOF for Enhanced C2H2/C2H4 and CO2 Selective Adsorptions.

A polar flow channel with embedded gas recognition pockets was made in a 10-connected hexanuclear yttrium-based metal-organic frameworks (MOF) NTUniv-57 (NTUniv = Nantong University) by lowering the symmetry of the ligand, which showed high chemical stability and obviously enhanced gas adsorption selectivities.

A multifunctional chemical linker in a buried interface for stable and efficient planar perovskite solar cells.

The buried interface between a perovskite (PVK) light absorbing layer and an electron transport layer (ETL) plays an utmost important role in further improving the efficiency and stability of planar perovskite solar cells (PSCs). The interfacial properties greatly affect charge transport, perovskite crystal growth, and device stability. Herein, a variable structure broad-spectrum UV-284 absorber agent 2-hydroxy-4-methoxybenzophenone-5-sulfonic acid (HMBS) is introduced into PSCs based on SnO2 ETLs as an efficient multifunctional chemical linker to modify the buried interface properties. HMBS used to modify SnO2 can simultaneously suppress the surface trap states of ETLs, optimize the ETL/PVK interface energy level arrangement, and improve the crystallization quality of the upper perovskite films. Meanwhile, as an efficient UV absorber, HMBS can also greatly reduce the damage caused by UV light to perovskite films and thus improve the stability of devices. Consequently, HMBS-modified PSCs exhibit champion efficiencies of 23.42% (0.09 cm2) and 20.63% (1.00 cm2) along with remarkably enhanced UV stability. This work emphasizes the importance of appropriate interface treatment strategies for buried interface modification and provides an effective method for fabricating efficient and UV resistant perovskite photovoltaic devices.

Finely Tuning Tridentate Carboxylic Acids for the Construction of Rod Scandium Metal-Organic Frameworks with High Chemical Stability and Selective Gas Adsorption.

By systematic ligand tuning for control of the secondary building units, the use of tridentate carboxylic acid to construct the rod scandium metal-organic framework NTUniv-55 (NTUniv = Nantong University) with high chemical stability and interesting selective gas adsorption was reported.

A Triazole Functionalized txt-Type Metal-Organic Framework with High Performance for CH4 Uptake and Selective CO2 Adsorption.

The metal-organic framework (MOF) NTUniv-54 (NTUniv = Nantong University) was assembled via utilizing click chemistry with densely decorated trizole units and exposed metal sites, which exhibited the best methane working ability (197 cm3·cm-3 from 100 to 5 bar and 177 cm3·cm-3 from 65 to 5 bar at 298 K), and the lowest CO2 Qst of 22.8 kJ·mol-1 in all triazole-MOFs at room temperature.

A Glass-Ceramic with Accelerated Surface Reconstruction toward the Efficient Oxygen Evolution Reaction.

The effective non-precious metal catalysts toward the oxygen evolution reaction (OER) are highly desirable for electrochemical water splitting. Herein, we prepare a novel glass-ceramic (Ni1.5 Sn@triMPO4 ) by embedding crystalline Ni1.5 Sn nanoparticles into amorphous trimetallic phosphate (triMPO4 ) matrix. This unique crystalline-amorphous nanostructure synergistically accelerates the surface reconstruction to active Ni(Fe)OOH, due to the low vacancy formation energy of Sn in glass-ceramic and high adsorption energy of PO4 3- at the VO sites. Compared to the control samples, this dual-phase glass-ceramic exhibits a remarkably lowered overpotential and boosted OER kinetics after surface reconstruction, rivaling most of state-of-the-art electrocatalysts. The residual PO4 3- and intrinsic VO sites induce redistribution of electron states, thus optimizing the adsorption of OH* and OOH* intermediates on metal oxyhydroxides and promoting the OER activity.

Recent Advances in Fast-Decaying Metal Halide Perovskites Scintillators.

Fast-decaying scintillators show subnanoseconds or nanoseconds lifetime and high time resolution, making them important in nuclear physics, medical diagnostics, scientific research, and other fields. Metal halide perovskites (MHPs) show great potential for scintillator applications owing to their easy synthesis procedure and attractive optical properties. However, MHPs scintillators still need further improvement in decay lifetime. To optimize the decay lifetime, great progress has been achieved recently. In this Perspective, we first summarize the structural characteristics of MHPs in various dimensions, which brings different exciton behaviors. Then, recent advances in designing fast-decaying MHPs according to different exciton behaviors have been concluded, focusing on the photophysical mechanisms to achieve fast-decaying lifetimes. These advancements in decay lifetimes could facilitate the MHPs scintillators in advanced applications, such as time-of-flight positron emission tomography (TOF-PET), photon-counting computed tomography (PCCT), etc. Finally, the challenges and future opportunities are discussed to provide a roadmap for designing novel fast-decaying MHPs scintillators.

Crystallization Regulation and Lead Leakage Prevention Simultaneously for High-Performance CsPbI2Br Perovskite Solar Cells.

All-inorganic CsPbI2Br perovskite is striking as a result of the reasonable band gap and thermal stability. However, the notorious air instability, unsatisfactory conversion efficiencies, and toxic water-soluble Pb2+ ions have greatly limited the further development of CsPbI2Br-based devices. Herein, a facile strategy is developed to prepare efficient and air-stable CsPbI2Br-based perovskite solar cells (PSCs) with in situ lead leakage protection. With the introduction of 2,2'-dihydroxy-4,4'-dimethoxy-5,5'-disulfobenzophenone disodium salt (BP-9) into the CsPbI2Br precursor solution, the crystallization of perovskite can be regulated at a reduced trap density, the uncoordinated Pb2+ ions and electron-rich defects in the structure can be passivated to suppress non-radiative recombination, and the energy level arrangement can be optimized to improve charge carrier transport. Consequently, the optimized PSC achieved a championship efficiency of 17.11%, accompanied by negligible J-V hysteresis and remarkably improved air stability. More importantly, the strong chelation of BP-9 with water-soluble Pb2+ ions minimizes the leakage of toxic lead in the perovskite structure.

Accelerating electrosynthesis of ammonia from nitrates using coupled NiO/Cu nanocomposites.

Herein, we report a nanocomposite electrocatalyst with coupled Cu and NiO, showing a high Faraday efficiency of 97% and excellent ammonia production rate (450 mg h-1 cm-2) for nitrate reduction. In situ UV-vis spectroscopic studies confirmed that the synergy between NiO and Cu could avoid NO2- enrichment and promote tandem nitrate reduction to ammonia synthesis.

Degradation of polyvinyl alcohol (PVA) in neutral conditions based on copper-manganese bimetallic catalyst.

There have been many studies on the degradation of polyvinyl alcohol (PVA) by the Fenton-like method, but the narrow acid-base (pH) range, poor degradation effect, and time-consuming of the Fenton-like method limit its development. Therefore, to improve the shortcomings of the Fenton-like method, the study aimed to synthesize copper-manganese bimetal oxide loaded catalysts (MnCuO@γ-Al2O3) through the impregnation calcination method, and its potential to activate hydrogen peroxide (H2O2) for the degradation of PVA was evaluated. The X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer Emmett Teller (BET), energy dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS) characterizations revealed the chemical composition, structure and morphology of the prepared MnCuO@γ-Al2O3, furthermore the synergistic mechanism was proposed. Results indicated that copper and manganese could successfully attach to γ-Al2O3 and reduce the specific surface area of γ-Al2O3, promoting the transformation of multivalent metals and the generation of oxygen vacancies. In addition, comparative experiments demonstrated that the PVA removal efficiency was significantly improved at the catalyst calcination temperature of 500 °C, reaction temperature of 70 °C, H2O2 dosage of 125 [Formula: see text], and catalyst dosage of 625 [Formula: see text] and more than 96% of PVA was removed within 20 min in neutral conditions. Lastly, four catalyst cycle degradation experiments of PVA were carried out, and the degradation effect could reach more than 96% in a certain time.

Rationalizing Functionalized MXenes as Effective Anchor Materials for Lithium-Sulfur Batteries via First-Principles Calculations.

The practical application of Li-S batteries has been greatly hindered by severe shuttle effects and sluggish kinetics. Anchoring soluble lithium polysulfides (LiPSs) onto host materials by chemisorption is an effective strategy for extending battery life. In this work, we performed systematic density functional theory calculations to evaluate the anchoring performance of O/F-covered MXene (M2TC2) in lithium-sulfur batteries. Our results indicate that the moderate anchoring strength (∼2.5 eV), outstanding sulfur reduction performance (UL > -0.6 V), and low lithium ion diffusion barrier (<0.2 eV) of Mo2CF2 and V2CF2 make them promising host materials for LiPSs. We further revealed the determinants of the strength of binding of LiPSs to M2CT2. On the basis of the strong correlation among QM, χO/F, and Ea, we established a "structure-property" equation to reveal the active origin of M2CT2. We expect that the framework established in this work will accelerate the development of Li-S batteries.