查找使用阿拉丁产品的科研文献

Multilayer dodecahedrons Zn-Co sulfide for supercapacitors

Jing Zhao,Shuangyue Hou,Yongqing Bai,Yue Lian,Qiuping Zhou,Chaolei Ban,Zhifeng Wang,Huaihao Zhang

Transition metal sulfides have attracted much attention in recent years due to their high theoretical specific capacitance and conductivity. In this work, the two-layer heterogeneous metal sulfides (Zn-Co-S) were prepared successfully using the zinc-cobalt fund organic framework as a sacrificial template. The composite materials were characterized by a variety of means and its performance as electrode material for supercapacitor was also tested in detail. Resultantly, the 2L-ZnCoS (two layers of Zn-Co-S) has good electrochemical properties: its specific capacitance is up to 971.01 C g −1 at the specific current of 1 A g −1 with 90.3% retention after 10,000 cycles. As for the asymmetric supercapacitor 2L-ZnCoS//AC assembled with 2L-ZnCoS as positive electrode and activated carbon as negative electrode, it showed excellent performance: when the power density was 0.80 kW kg −1 and 8.09 kW kg −1 , the energy density were as high as 51.76 Wh kg −1 and 31.63 Wh kg −1 correspondingly. This advanced performance is due to its unique double-layer hollow structure and the synergistic effect, which are helpful to acquire more electrochemical active sites and transport pathways to accelerate ion transport. Accordingly, the well-designed double-layer hollow composite sulfide is an ideal electrode material for high performance supercapacitors .

Co-upcycling of polyvinyl chloride and polyesters

Cao Ruochen,Zhang Mei-Qi,Jiao Yuchen,Li Yuchen,Sun Bo,Xiao Dequan,Wang Meng,Ma Ding

Catalytic upcycling of plastic wastes to valuable chemicals offers the opportunity to simultaneously address the enormous environmental problems associated with plastics and achieve the circular economy. However, the upcycling of plastic wastes containing polyvinyl chloride (PVC) is particularly challenging due to the interference of chlorine, which can be released during PVC depolymerization and deactivate the catalyst. Here we present a catalytic process for the co-upcycling of PVC and polyethylene terephthalate (PET). By using a chlorine-containing ionic liquid as the catalyst/solvent and ZnCl 2 as Lewis acid catalyst, with in situ utilization of PVC-released chlorine, we successfully converted PET into terephthalic acid and 1,2-dichloroethane with high yields. The results reveal that chlorine from PVC, previously considered detrimental to the transformation of other polymers and the cause of catalyst poisoning, can actually have a positive role in the upcycling of plastic wastes. This work can incentivize further progress in plastics upcycling and pave the way to sustainable plastic wastes management, moving societies one step forward towards realizing the circular economy.

Elastic flexibility of ferroelectric supramolecular co-crystals

Qianqian Luo,Chunli Jiang,Hechun Lin,Chunhua Luo,Ruijuan Qi,Hui Peng

NO oxidation over Ni–Co perovskite catalysts

Shifa Zhong,Yuanyuan Sun,Hongchuan Xin,Chunpeng Yang,Lei Chen,Xuebing Li

LaNi 1 − x Co x O 3 ( x   =   0, 0.1, 0.3, 0.7, 1.0) perovskite catalysts were prepared by co-precipitation method and investigated in the catalytic oxidation of NO. LaNi 0.7 Co 0.3 O 3 showed the best catalytic activity among all the samples, confirming the potential of LaNi 0.7 Co 0.3 O 3 as a cheap and efficient NO oxidation catalyst. The high reactivity of LaNi 0.7 Co 0.3 O 3 was mainly due to the moderate amount of adsorbed NO and O 2 and their moderate adsorption strength on the surface of the catalyst, as determined by the XRD, H 2 -TPR, NO-TPD, O 2 -TPD and XPS studies.

N-doped ordered mesoporous carbon embedded with Ni-N₃-Pyr sites achieve nearly 100% selectivity for CO₂RR to CO

Di Jin,Yunpeng Zou,Yang Zhao,Shuai Chen,Shiwei Luo,Taotao Chen,Jinchuan Zhang,Jialin Chen,Jijie Li,Yuewen Mu,Wen-Yan Zan,Fengwei Zhang

Transition metal-nitrogen-carbon (M-N-C) catalysts show great promise for converting CO₂ into valuable fuels and chemicals via electroreduction (CO₂RR). Nonetheless, controversy remains regarding which specific MNₓ coordination structure in M-N-C catalysts governs CO₂RR performance. We synthesized a series of Ni-NOMC catalysts with high specific surface area and varying NiN₃-Pyr site loadings using SBA-15 as a template, employing a small molecule condensation and pyrolysis strategy. Aberration-corrected scanning transmission electron microscopy (AC-STEM) and X-ray absorption spectroscopy (XAS) confirmed the presence of atomically dispersed Ni sites coordinated by pyrrolic nitrogen (NiN₃-Pyr). The Ni-NOMC-3 catalyst, with a higher NiN 3 -Pyr loading, achieved a remarkable CO Faraday efficiency (FE CO ) of 99.6% at −0.57 V vs. the reversible hydrogen electrode (RHE), while maintaining FE CO > 99% across a broad potential window (−0.17 to −0.97 V vs. RHE). Moreover, the ordered mesoporous structure of this catalyst enhances mass transport properties and optimizes active site accessibility, enabling a high CO partial current density of 157 mA·cm⁻² in a flow cell system. Theoretical simulations further reveal that the NiN₃-Pyr coordination structure exhibits superior catalytic performance for CO₂RR-to-CO compared to other possible NiN x configurations.

Glycyl-l-histidyl-l-lysine as a novel co-former in co-amorphous systems: Enhanced aqueous solubility and physical stability

Qiang Huang,Zhiren Zou,Dian Cheng,Ruyu Gao,Lin Zhou,Wencheng Wu,Yinyin Yuan,ChangJu Chun,Yuye Huang,Guang Liang,Wenqi Wu

Co-amorphous systems have emerged as a promising strategy to enhance the aqueous solubility of poorly water-soluble drugs. Although amino acids have been widely studied as co-formers, some amino acid-based co-amorphous systems exhibit limited dissolution improvement and inadequate physical stability. In this study, glycyl- l -histidyl- l -lysine (GHK) was selected as a co-former due to its biocompatibility and multiple functional groups, which were expected to enhance the dissolution and the physical stability of pure amorphous drugs. Basic mebendazole, neutral tadalafil and acidic indomethacin were selected as the model drugs. Glycine, histidine and lysine were used as co-formers for comparison. All drug-co-former combinations were prepared by ball milling at a 1:1 molar ratio. GHK achieved complete amorphization with all three model drugs within 15 min of milling, whereas most amino acid-based mixtures remained partially crystalline even after 60 min of milling. The formation of homogeneous amorphous forms was confirmed by differential scanning calorimetry, indicated by a single glass transition temperature in the drug-GHK system. The drug-GHK systems exhibited significantly enhanced dissolution performance, including faster dissolution rates, higher drug concentration and sustained supersaturation (up to 1440 min) compared to both the pure crystalline and amorphous drugs. Furthermore, physical stability studies confirmed that GHK-based systems maintained amorphous forms for at least 6 months, outperforming both amino acid-based counterparts and pure amorphous drugs. Notably, salt formation and hydrogen bonding were associated with the observed improvements in dissolution performance and physical stability. In conclusion, GHK represents a promising co-former, expanding the design space for co-amorphous systems.

Photo-assisted methane dry reforming over Ni–Co–CeO2–Al2O3 catalysts with enhanced activity: synergistic effect of Ni and Co

Jiming Wang,Min Ji,Min Wang

Photo-thermo-chemical dry reforming of methane (PTC-DRM) presents advantages over thermocatalytic DRM by storing solar and thermal energy as chemical energy, yet maintaining high efficiency and stability remains a challenge. Herein, we report an efficient PTC-DRM process on Ni–Co–Ce–Al catalysts and investigate the synergistic effect of Ni and Co on reaction performance. Characterization results revealed that the introduction of Co increases the concentration of acidic sites on the Ni-based catalyst surface. An appropriate number of acidic sites facilitates the DRM reaction. Co-incorporated catalysts demonstrate excellent light responsiveness, and generate more energetic hot charge carriers under light irradiation. Density functional theory (DFT) calculations confirm that the interfacial electronic structure of the Ni–Co–Ce–Al catalyst facilitates spontaneous electron transfer from CeO2 to NiCo bimetallic quantum dots (QDs), which is mediated by the built-in electric field at the metal–semiconductor interface—attributed to the inherent work function difference between CeO2 (5.45 eV) and NiCo alloys (4.93 eV). The incorporation of an optimal amount of Co significantly improves the catalytic performance, with the Ni0.9–Co0.1–Ce–Al catalyst exhibiting the highest thermal and photocatalytic activity. At 650 °C, the conversions of CH4 and CO2 increased from 55.8% and 60.1% under dark conditions to 65.1% and 67.9% under light irradiation, respectively. Accordingly, the yields of H2 and CO increased from 21.4 and 26.5 μmol min−1 g−1 to 23.6 and 27.7 μmol min−1 g−1. This study demonstrates that the synergy between bimetallic components coupled with photothermal integration can effectively enhance DRM efficiency and coke resistance, providing a valuable catalyst design strategy for solar-driven conversion of carbon resources.

Synergizing W/H Co-Doping and Oxygen Vacancy Incorporation in TiO 2 for CO 2 Photoreduction

Qunhua Zhong,Yimeng Zhou,Tianle Ren,Jianjun Zhu,Di Li,Deli Jiang

Abstract Photocatalytic CO2 reduction to carbonaceous fuels is a promising strategy to mitigate massive carbon emissions, yet the highly selective CO2 conversion remains challenging due to the unsatisfactory charge separation and limited active sites of pristine semiconductor photocatalysts. Herein, we report the in situ fabrication of oxygen vacancy rich W/H co-doped rutile TiO2 (W/H-TiO2) via a two-step wet chemical approach for high-efficiency photocatalytic CO2 reduction to CO. The optimized W/H-TiO2 exhibited high activity and selectivity for the photocatalytic reduction of CO2 to CO (57.96 μmol g–1 h–1 and 96.3%), which were significantly higher than those of other TiO2 counterparts. Experimental characterizations and density functional theory (DFT) calculations reveal that the synergistic effect of H/W co-doping accelerates the migration and separation of photogenerated charge carriers and reduces the formation energy barrier for the key *COOH intermediate, thereby markedly boosting the CO2 photoreduction activity and product selectivity of W/H-TiO2. This work establishes a dual-doping-induced oxygen vacancy strategy for electronic structure engineering, providing a new paradigm for the rational design of high-performance TiO2 based photocatalysts toward efficient CO2 photoreduction.

Bimetallic Co/Fe-MOF derived from poly(butylene adipate-co-terephthalate) (PBAT) plastic wastes for efficient interfacial solar steam generation

Shuyu Liu,Liang Tian,Lihua Han,Qing Li,Liangliang Zhu,Su Chen

The conversion of waste plastics into metal-organic framework (MOF) photothermal materials presents promising opportunities for solar energy conversion, facilitating freshwater production and water purification through interfacial solar evaporation, and simultaneously heralding advancements in plastic waste recycling. Herein, we present a bimetallic Co/Fe-MOF photothermal converting material derived from PBAT-based plastic wastes, tailored for efficient solar water evaporation. The nanosheet-structured bimetallic Co/Fe-MOF featuring high light absorption, water wettability and photothermal conversion efficiency delivers an optimal evaporation rate of 1.81 kg m −2  h −1 under one sun irradiation, surpassing that of monometallic MOFs. Moreover, we employed three substrates—nanofiber film, aerogel, and hydrogel—to immobilize the Co/Fe-MOF solar absorbers, thereby constructing monolithic hybrid solar evaporators. These substrates not only confer the flexibility to Co/Fe-MOF solar absorbers for practicability but also serve as mediates to regulate thermal management and water states. Consequently, the hybrid evaporators exhibited significantly enhanced evaporation rates, with the hydrogel evaporator achieving to ~3.53 kg m −2  h −1 , coupled with remarkable salt resistance and durability. This bimetallic Co/Fe-MOF-based solar evaporator efficiently serves a dual purpose, enhancing clean water production through solar desalination and purification while also presenting a viable alternative to the issue of plastic waste, potentially harmonizing energy, environment and clean water nexus.

Engineering Ru catalysts on sulfur-vacancy-rich MoS2 via Co doping and CO dual-functional regulation for enhanced alkaline HER

Yuqing Pan,Zechu Deng,Ning Liu,Chengna Dai,Biaohua Chen

The alkaline hydrogen evolution reaction (HER) suffers from sluggish kinetics, mainly due to the high energy barrier for water dissociation and mismatched adsorption-desorption balance of key intermediates (H* and OH*). To address this challenge, this study employs a dual-functional strategy combining Co doping and in-situ CO regulation to construct a Co-MoS 2 support with abundant sulfur vacancies (Sᵥ). These Sᵥ can efficiently anchor Ru species as highly dispersed, electron-deficient Ru 4+ state, which leads to excellent alkaline HER performance of Ru 8% @Co-MoS 2 -CO by displaying a low overpotential of 46 mV at 10 mA cm −2 and a Tafel slope of 62 mV dec −1 . Combined experimental characterization and DFT (density functional theory) calculations reveals that Co-Sᵥ synergy not only optimizes Ru’s electronic structure with downshift d band center but also finely modulates the electronic properties of adjacent S site, which thereby enables precise tuning of the adsorption/desorption (ADT) behavior of OH* and H*. Meanwhile, the significantly increased electronic density around the Fermi energy (E F ) leads to enhanced efficiently electronic conductivity of Ru 8% @Co-MoS 2 -CO, as also verified by the SECM measurement, which constitutes another key factor leading to its excellent alkaline HER activity. In addition to that, it is also interestingly found that there probably also exists another route for H evolution, wherein the H* can migrate from the S site to the Ru site by crossing a low energy barrier of 0.83 eV and be evolved into H 2 by following Tafel route, jointly boosting reaction efficiency. Generally, present work provides atomic-scale insights and references for designing high-performance electrocatalysts via defect engineering-regulated metal-support interactions, which would favor other highly-efficient alkaline HER catalyst designs.

Hierarchical Co/CoO/FeO/C nanocomplex derived from Co(OH)2@NH2-MIL-88 to aid highly efficient microwave absorption

Peng Miao,Weixing Chen,Kailei Li,Weifeng Zhao,Jie Kong

Design of microwave absorbents with hierarchical interfacial structures has become an effective method to scatter microwaves. Metal/carbon composites derived from metal–organic frameworks (MOFs) have attracted considerable attention due to their tunable chemical composition and microstructure. We describe the facile synthesis of a Co/CoO/FeO/C nanocomplex employing Co(OH)2 on NH2-MIL-88B as the “sacrificial template” through one-step pyrolysis. The as-prepared flaky-like Co/CoO/FeO/C nanocomplex showed an effective absorption width of 4.7 GHz at 1.86 mm and a minimum reflection loss of −45.5 dB at 2.01 mm. Our study can aid design of a microstructural strategy for preparing high-performance microwave absorbents.

Structure and mechanical properties of Poly(styrene-co-acrylate)/cellulose nanocrystals co-continuous composites via one-pot pickering emulsion polymerization

He Yi,Jiang Maoping,Hu Wen,Ahmad Ishak,Gan Lin,Pang Aimin,Huang Jin

Nanoparticle-doped polymeric composites usually suffer from poor mechanical toughness and strength, due to the hard formation of co-continuous submicron structure between matrix and nanoparticles. Here, a universal strategy to construct a co-continuous submicron structure in nanoparticle-doped polymeric composites was proposed for significant mechanical enhancement via integrating Pickering emulsion and copolymerization. The surface-grafted cellulose nanocrystals (CNCs) acted as the solid surfactant of Pickering emulsion forming an isolated percolation network, combined with the copolymerization of surface-grafted CNCs and polymer matrix, generating stronger interaction in composites. The poly(styrene- co -acrylate)/methylacryloyl-grafted CNC (PSA/mCNC) composites were obtained from one-pot Pickering emulsion polymerization. The tensile strength and the elongation at break of PSA/mCNC composites increased by 107% and 681%, respectively, when mCNCs were 0.5 wt%. The mechanical performance of PSA/mCNC composites exceeded the best PSA/CNC composites, whose tensile strength and the elongation at break only increased by 51% and 650%, respectively. The PSA/mCNC composites showed higher mechanical performance and simpler post-process, compared with similar commercial products. This strategy is universal for mechanical enforcement of other polymeric composites.