ACS Sustainable Chemistry & Engineering
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2025
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IF 7.3
Mei Ma,Jia-qi Bai,Huangfei Liu,Ben Liu,Zhangkai Qian,Suiqin Li,Jingshuai Chen,Mengdie Cai,Song Sun
The preparation of methyl-substituted amines by direct N-methylation of amines with CO2/H2 is an important reaction for CO2 utilization and organic synthesis. However, the design and construction of effective and stable non-noble-metal catalysts for this reaction remain challenging. Here, a cheap non-noble-Cu-based catalyst was prepared and applied in the direct N-methylation reaction of N-methylaniline with CO2 and H2. 5%Cu-ZnO(3.75%)/TiO2 showed 98.8% yield with an initial TOF of 7.7 h–1 after 24 h under 453 K, 1.5 MPa CO2, and 4.5 MPa H2, which was superior to 5%Cu/TiO2, 5%Cu/ZnO, and reported Cu-based catalysts. Furthermore, 5%Cu-ZnO(3.75%)/TiO2 can be reused at least four times and applied to the direct N-methylation of various amines with excellent selectivity. The various characterizations and experimental results showed that Cu0 was the active site, and 5%Cu-ZnO(3.75%)/TiO2 exhibited the largest surface Cu0 amount, thereby contributing to superior catalytic performance. The reaction mechanism of the direct N-methylation reaction of N-methylaniline with CO2 and H2 was proposed based on spectroscopic studies, kinetic studies, and control experiments. The reaction proceeded with the HCHO and N-methylformanilide intermediates, and the formation of HCHO from H2 and CO2 was the rate-determining step.
研究领域:
化学工程
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催化科学
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材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2026
·Vol. 14
·期 5
·123675
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IF 7.5
Bicai Li,Hongrui Zhao,Chenxi Li,Hui Fu,Yuanping Li,Yi Huang,Guowen He
Biorefractory protein-like dissolved organic matter (DOM) in swine wastewater presents a formidable challenge for photocatalytic degradation, whereas binary photocatalysts suffer from intrinsic limitations of inefficient charge separation and poor selective DOM adsorption. To mitigate these critical drawbacks, we designed ZnO/TiO 2 -rGO ternary photocatalysts with tunable oxygen vacancy (O V ) concentrations and a Type Ⅱ heterojunction by regulating rGO dosages via a two-step hydrothermal method, achieving dual optimization of charge transfer dynamics and selective DOM adsorption. The optimal ZTR-4 catalyst (O V concentration 45.32%) achieved 69.40% protein-like DOM removal, with a rate constant 3.4 and 2.3 times higher than binary composites (ZR and TR). Excitation-emission matrix (EEM) and UV–visible spectral analyses confirmed the conversion of labile protein-like DOM to refractory humic-like and fulvic-like substances via oxidative condensation and Maillard reactions, with superoxide anion radicals (·O 2 - ) and photogenerated holes ( h + ) serving as the dominant reactive species. The enhanced performance stemmed from the synergy of heterojunction-mediated charge separation, rGO-facilitated electron transport, π-π adsorption, and O V -induced photogenerated carrier recombination suppression. This work not only verifies the application potential of the as-prepared materials in real livestock wastewater, but also clarifies the intrinsic degradation and humification mechanisms of complex DOM.
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DOI
高影响因子
ELECTROCHIMICA ACTA
·
2026
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IF 5.8
Bowen Li,Liyang Qin,Weihua Ma,Binbin Yao,Jiahao Wang,Ye Song,Qianqiao Chen,Chengyuan Li,Xufei Zhu
The recombination of photogenerated carriers limits the photoelectrochemical (PEC) efficiency of titanium dioxide (TiO 2 ) nanotubes. To address this, we constructed a type Ⅱ ZnO/TiO 2 heterostructure via in situ hydrothermal loading of ZnO nanoparticles onto highly ordered anodic TiO 2 nanotube arrays. A critical interplay between precursor soaking duration (1 day vs. 5 days) and hydrothermal temperature (120 °C vs. 150 °C) was uncovered, that is, prolonged soaking and lower hydrothermal temperatures were beneficial for enhancing photocurrent. A two-step annealing process utilized in this work can enhance precursor infiltration into the nanotube channels, promoting uniform ZnO nucleation and robust interfacial adhesion. The optimized heterostructure electrode achieved a nearly twofold increase in carrier concentration (from 5.56 × 10 18 to 1.14 × 10 19 cm -3 ) along with reduced charge-transfer resistance and enhanced charge separation efficiency compared to unmodified TiO 2 . Electrochemical impedance spectroscopy study revealed that the modified heterostructure electrode exhibits lower surface charge-transfer resistance and higher bottom barrier-layer resistance than the unmodified electrode, thereby facilitating efficient interfacial charge transfer and suppressing dark current. Using glucose as a probe, the modified electrode delivered a higher photocurrent density and a faster response than the unmodified one. This work provides an alternative approach to optimizing semiconductor heterojunctions, and the improved process demonstrates promising potential for glucose sensing applications.
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DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2021
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IF 4.821
Yanyan Niu,Yuxue Chen,Xiaoping Zhang,Hui Xie,Guiling Luo,Wei Sun
In this paper a photoelectrochemical (PEC) aptasensor based on specific recognition between aptamer and target cadmium ion (Cd(II)) with change of the sensing interface structure was constructed. A ZnO-TiO 2 nanocomposites and Au nanochains (Au NCs) modified electrode as photosensitive substrate was prepared and further covalently bound with graphite-like carbon nitride (g-C 3 N 4 ) on the free end of the aptamers to amplify the detection signal, which was applied to Cd(II) detection. Graphite-like carbon nitride with narrow band gap exhibited unique photoelectric property under UV and visible light irradiation. When the target Cd(II) was detected by the modified interface of the aptasensor, the structure of sensing interface was changed with the signal sensitizer g-C 3 N 4 closed to the interface, which caused the changes of photocurrent signal more sensitive and exhibited a good linear relationship with the Cd(II) concentration, so as to realize the quantitative analysis of the target. This PEC aptasensor showed a high sensitivity with a detection limit as 1.1 × 10 −11 mol/L and was further applied to the water sample detection successfully.
研究领域:
分析化学
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环境科学
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材料科学
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产品关联
DOI
高影响因子
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