JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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2019
·
IF 2.752
Chongyan Hao,Yuan Liao,Yang Wu,Yajing An,Jiannan Lin,Zhengfei Gu,Minhong Jiang,Shi Hu,Xiaotian Wang
In this work, we report RuO 2 -loaded TiO 2 –MXene hybrid nanostructure as a promising photocatalyst possessing remarkable activity for photocatalytic nitrogen fixation in water at room temperature. The MXene was synthesized by HF etching of the precursor Ti 3 AlC 2 and used as the substrate for the growth of RuO 2 nanoparticles and TiO 2 through a hydrothermal reaction . The benign activity is mainly attributed to the synergetic effect among MXene, TiO 2 , and RuO 2 in photocatalytic ammonia synthesis by combining light harvesting and nitrogen activation.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
高影响因子
ACS Applied Energy Materials
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2020
·
IF 4.473
Huijuan Han,Yang Yang,Jiafang Liu,Xiuzhen Zheng,Xulin Wang,Sugang Meng,Sujuan Zhang,Xianliang Fu,Shifu Chen
Photocatalytic nitrogen fixation is considered as a very promising technology to solve the high-energy consumption problem in industrial ammonia synthesis. Because of the mildness of reaction conditions, its development is still limited by the low reaction efficiency and unknown reaction mechanism. Inspired by the mechanism of biological nitrogen fixation in nature, Zn3In2S6 with different sulfur sources is prepared to study the effects of cation defects on the adsorption, activation, and reaction in photocatalytic nitrogen fixation. Because of the electron-rich property of zinc vacancies in Zn3In2S6 nanosheets, it can effectively activate the N≡N triple bond, thereby increasing the rate of kinetic reduction. With the activation of N2 molecules on zinc vacancies, the existing protons obtained from methanol (solvent) will greatly accelerate the electron transfer between interfaces during the nitrogen reduction reaction. Notably, Zn3In2S6 with rich Zn vacancies exhibits higher activity (355.2 mg L–1 gcat–1, 15 times) than Zn3In2S6 with poor vacancies in nitrogen fixation. This work describes the contribution of zinc vacancies to the fixation and activation of nitrogen molecules, which is very important to establish a highly effective system of photocatalytic nitrogen fixation.
研究领域:
材料科学
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催化化学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF THE ENERGY INSTITUTE
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2022
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IF 6.47
Yunwu Zheng,Donghua Li,Jida Wang,Yifei Chen,Can Liu,Yi Lu,Xu Lin,Bohan Lv,Jirong Li,Zhifeng Zheng
To investigate the nitrogen migration and transformation mechanisms that produce high value-added N-containing chemicals, the NH 3 /N 2 torrefaction pretreatments of waste biomass for the production of renewable N-containing compounds were explored, and the effects of torrefaction temperature (200, 225, 250, 275, 300 °C) on fuel properties, structure, crystallinity , surface functional groups and thermal kinetics were evaluated by element analysis, X-ray diffraction (XRD), scanning electron microscopy (SEM), fourier infrared spectroscopy (FTIR) and thermogravimetric analysis (TG-DTG). The effects of subsequent catalytic ammonization pyrolysis upgrading of the torrefied biomass with Co/HZSM-5/HZSM-5 catalysts under an NH 3 /N 2 atmosphere on product yield and N-containing compound selectivity were also evaluated with GC/MS and UV-fluorescence spectrometry. Furthermore, nitrogen fixation and migration mechanisms were also proposed in depth. The results showed that NH 3 torrefaction was more effective in enhancing N fixation and retarding the release of N-containing volatiles in torrefied biochar (0.26%–9.43%) and reducing the oxygen content (43.18%–21.81%) via Maillard reactions compared with N 2 torrefaction. With increasing torrefaction severity, the N-containing compound content, higher heating values (HHV), deoxygenation ratio (DEO) and nitrogen-doping ratio (NDR) increased, which were much higher than those of conventional N 2 torrefaction. Higher temperatures promoted the evolution of graphitic-N and oxidized-N and reduced pyrrolic-N and pyridinic-N group formation in torrefied biochar. The maximum content of N-containing compounds of 88.71% was obtained at a torrefaction temperature of 275 °C under NH 3 pyrolysis coupled with the Co/HZSM-5 catalyst, and was achieved via substrate interaction with the -Co-O-Si- catalyst sites and Maillard reactions. Furthermore, the N 2 atmosphere combined with the HZSM-5 catalyst significantly promoted the conversion of HC compounds (∼56.97% at 225 °C during N 2 torrefaction), while the Co/HZSM-5 catalyst combined with the NH 3 atmosphere significantly improved N-containing compound formation. NH 3 pyrolysis facilitated the formation of pyrroles and pyrazines while reducing the formation of amides by deamination and dehydrogenation reactions. Cellulose was conducive to the transformation of pyrrole in NH 3 pyrolysis, while lignin was conducive to the formation of aniline. These results could offer strategies to regulate nitrogen functional groups to enhance N-containing chemicals.
研究领域:
能源与环境科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2023
·
IF 7.3
Guangmin Ren,Zehui Zhao,Zizhen Li,Zisheng Zhang,Xiangchao Meng
Herein, we applied a rapid Joule heating method to form oxygen vacancies and further induced the deposition of Ru clusters onto BiVO 4 . The rapid Joule heating method fabricated oxygen vacancy on BiVO 4 , resulting in the formation of electron-rich active Ru sites and unsaturated V sites. The pristine BiVO 4 was almost no activity in photocatalytic ammonia synthesis. The photocatalytic production rate of ammonia was increased to 3.88 μmol g - 1 h -1 after the formation of oxygen vacancies, and further increased to 16.57 μmol g -1 h -1 with Ru clusters loaded on BiVO 4 . It was indicated that unsaturated V sites near the oxygen vacancy and Ru clusters might act as the reactive sites for N 2 adsorption and activation. And the strong metal-support interactions between Ru and BiVO 4 resulted in charge redistribution between Ru clusters and BiVO 4 supports, thus reducing energy barrier of the rate-determining step for the N 2 hydrogenation. Furthermore, DFT confirmed that associative alternating pathway was suitable for this process.
研究领域:
材料科学
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化学工程
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环境科学
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产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2022
·
IF 5.723
Yuanfang Shen,Jingxuan Shou,Liangchen Chen,Weihang Han,Luping Zhang,Yutong Chen,Xuewei Tu,Shangfu Zhang,Qiang Sun,Yurong Chang,Hui Zheng
Photocatalytic nitrogen fixation from air directly under sunlight can contribute significantly to carbon neutralization. It is an ideal pathway to replace the industrial Haber Bosch process in future. A Fe-doped layered WO 3 photocatalyst containing oxygen vacancies was developed which can fix nitrogen from air directly under sunlight at atmospheric pressure. The iron doping enhances the transport efficiency of photogenerated electrons. The photocatalytic efficiency is around 4 times higher than that of pure WO 3 . The optium nitrogen fixation conditions were examined by orthogonal experiments and its nitrogen fixation performance could reach up to 477 μg·g cat −1 ·h −1 under sunlight. In addition, the process of nitrogen fixation was detected by situ infrared, which confirmed the reliability of nitrogen fixation. Also, modeling on the interactions between light and the photocatalyst was carried out to study the distribution of surface charge and validate the light absorption of the photocatalyst. This work provides a simple and cheap strategy for photocatalytic nitrogen fixation from air under mild conditions.
研究领域:
材料科学
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环境科学
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化学工程
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产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2024
·
IF 6.5
Zhenyu Liu,Min Luo,Yue Cao,Linghu Meng,Yang Yang,Xiaoman Li
Doping elements in photocatalysts is a reliable strategy for efficiently utilizing solar energy. Herein, we reported the successful synthesis of S-doped Bi 2 MoO 6 (S-BMO) through a facile one-step solvothermal method utilizing Na 2 S as a sulphur source. By systematically adjusting the doping concentration of S 2- ion, it was found that when the optimal doping amount of Na 2 S was 0.7 %, the obtained photocatalyst showed a photocatalytic nitrogen fixation rate of 122.14 μmol·h −1 ·g cat -1 under visible light irradiation for 1 h, which was 3.67 times better than Bi 2 MoO 6 (BMO). Density Functional Theory (DFT) calculations demonstrated that S partially substituted O in Bi-O-Mo in S-BMO and also modulated the electronic structure of BMO. The photoreduction ability was enhanced due to the upshift of the conduction band (CB) energy level from −0.6 to −0.72 eV after S doping. This work may provide a promising method for efficient photocatalytic nitrogen fixation by doping BMO with non-metallic elements.
研究领域:
材料科学
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环境科学
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化学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2021
·
IF 6.707
Xiaojing Yu,Haoran Qiu,Zhe Wang,Bin Wang,Qingnan Meng,Shaodong Sun,Yufei Tang,Kang Zhao
Aiming at comparing the charge separation efficiencies of various heterojunctions, such as p-n junction, metal–semiconductor junction, Z-scheme junction, TiO 2 -Au, TiO 2 -BiOI, TiO 2 -BiOI-Au and TiO 2 -Au-BiOI were synthesized by using n-type TiO 2 , p-type BiOI and plasmon metal Au as components for photocatalytic nitrogen fixation. The as-prepared “Z-scheme” TiO 2 -Au-BiOI photocatalyst showed the highest photocatalytic performance for N 2 photofixation with 543.53 μmol L −1 h −1 g −1 in the pure water system, which is 1.68 times higher than that of TiO 2 -BiOI-Au nanocomposite, 1.85 times higher than that of TiO 2 -BiOI and 6.69 times higher than that of TiO 2 -Au, revealing superiority of the heterojunctions of TiO 2 -Au-BiOI in kinetics among these different heterostructured photocatalysts during the photocatalytic N 2 reduction process. Moreover, the as-prepared TiO 2 -Au-BiOI exhibited considerable performance under real natural environment, showing a promising potential in future application.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
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2019
·
IF 5.589
Abuduheiremu Awati,Halidan Maimaiti,Shixin Wang,Bo Xu
Photocatalytic synthesis of ammonia is a kind of compelling and challenging nitrogen fixation method. In this paper, we extract the small-sized graphite-like carbon layer in the coal by organic solvent extraction method using HNO3 pretreated coal as a precursor. Then the coal-based carbon nanosheets (CNs) containing with Ca 2+ , Ti 4+ , Fe 2+ , Al 3+ , Si 4+ , C, N, O and other metal/non-metal ions was obtained under the assistance of the ultrasonication. The composite catalyst Ru/CNs was prepared by in situ loading the ruthenium (Ru) nanoparticles reduced from RuCl3·3H2O onto the as prepared CNs. The structure was characterized and the photocatalytic nitrogen fixation into ammonia performance under ambient temperature and atmospheric pressure was studied. The results show that the composite catalyst Ru/CNs with uniform dispersion of Ru nanoparticles on CNs has excellent photocatalytic nitrogen fixation activity, a nd the NH3 yield reaches 221.3 μmol/L after the reaction for 4 h. At the same time, the as prepared catalyst had quite good stability, and the NH3 yield remained substantially unchanged in 5 cycle experiments.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
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2020
·
IF 8.758
Benteng Sun,Zhangqian Liang,Yeye Qian,Xuesong Xu,Ye Han,Jian Tian
Here, we reported that sulfur vacancy-rich O-doped 1T-MoS2 nanosheets (denoted as SV-1T-MoS2) can surpass the activity of Pt as cocatalysts to assist in the photocatalytic nitrogen fixation of CdS nanorods. SV-1T-MoS2 cocatalysts exhibit sulfur vacancies, O-doping, more metallic 1T phase, and high electronic conductivity, thus leading to the exposure of more active edge sites, high Brunauer–Emmett–Teller surface area, enhanced visible light absorption, and improved electron separation and transfer, which are beneficial for photocatalytic nitrogen fixation. Consequently, the optimized 30 wt % SV-1T-MoS2-/CdS composites exhibit an outstanding nitrogen fixation rate of 8220.83 μmol L–1 h–1 g–1 and long-term stability under simulated solar light irradiation, significantly higher than pure CdS nanorods, CdS–Pt (0.1 wt %), and 30 wt % 1T-MoS2/CdS composites. The catalytic mechanism of photocatalytic nitrogen fixation on SV-1T-MoS2 is discussed by density functional theory calculations.
研究领域:
材料科学
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环境科学
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化学
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Xingxing Huang,Yingzhang Shi,Cheng Liu,Zhiwen Wang,Jinhong Bi,Jimmy C. Yu,Ling Wu
A series of Cu 2 O clusters/MIL-100(Fe) heterojunctions with different Cu 2 O mass ratios were constructed as the photocatalysts for N 2 fixation. An optimal nitrogen fixation performance of 51.22 μmol·g −1 ·h −1 is achieved when the mass fraction of Cu 2 O is 20 %. Isotope analysis experiments confirmed that the nitrogen source is N 2 . Possible intermediate signals during photocatalytic reactions were detected by in situ DRIFTS. XPS results further confirm the formation of Cu 2 O/MIL-100(Fe) heterojunctions, and that the existence of Cu–O surface interactions is the key to efficient electron transfer. It is revealed that the improvement of the catalytic performance is derived from the formation of heterojunction which regulates the energy band structure as well as promotes the separation of photogenerated electron-hole pairs. This study proposes a possible mechanism of photocatalytic nitrogen fixation and emphasizes the role of surface interaction and electron transfer in type-II heterojunction in improving nitrogen fixation performance.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 47
·22234-22242
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IF 3.591
Libo Wang,Mohan Li,Shiyu Wang,Tingting Zhang,Fengyan Li,Lin Xu
The problem of energy crisis promotes the development and utilization of materials related to the application of solar energy. Employing solar energy for clean photocatalytic nitrogen fixation is an effective approach to replace the high-energy consumption Haber–Bosch nitrogen fixation method to alleviate the energy crisis. In this article, mulberry-like BiVO4 containing oxygen vacancies (OVs–BVO) was prepared by the solvothermal method. In order to further elevate the catalytic effect of the catalyst, Ag nanoparticles with uniform distribution were loaded on the surface of OVs–BVO by the photodeposition method. A variety of survey techniques were performed to characterize the properties of the materials, including XRD, SEM, TEM, Raman, XPS, EPR, DRS, PL and Kelvin probe study. The results show that the subband (defect level) generated by the presence of OVs can accommodate low energy electrons to activate the adsorbed N2. Ag nanoparticles firmly attached on the surface of OVs–BVO produced a strong local surface plasmon resonance (LSPR) effect, which promoted the utilization of light energy and the effective separation of electron–hole pairs. The electrons have no interfacial barrier to overcome during the transfer between Ag and BVO due to their Ohmic contact. The application of Ag loaded OVs–BVO as a catalyst provides a new direction for the study of catalysts in the field of photocatalytic nitrogen fixation.
研究领域:
材料科学
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环境科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2020
·
IF 14.612
Peishen Li,Ziang Zhou,Qiang Wang,Ming Guo,Shaowei Chen,Jingxiang Low,Ran Long,Wen Liu,Peiren Ding,Yunyun Wu,Yujie Xiong
Photocatalytic nitrogen fixation represents a green alternative to the conventional Haber–Bosch process in the conversion of nitrogen to ammonia. In this study, a series of Bi5O7Br nanostructures were synthesized via a facile, low-temperature thermal treatment procedure, and their photocatalytic activity toward nitrogen fixation was evaluated and compared. Spectroscopic measurements showed that the tubular Bi5O7Br sample prepared at 40 °C (Bi5O7Br-40) exhibited the highest electron-transfer rate among the series, producing a large number of O2.– radicals and oxygen vacancies under visible-light photoirradiation and reaching a rate of photocatalytic nitrogen fixation of 12.72 mM·g–1·h–1 after 30 min of photoirradiation. The reaction dynamics was also monitored by in situ infrared measurements with a synchrotron radiation light source, where the transient difference between signals in the dark and under photoirradiation was analyzed and the reaction pathway of nitrogen fixation was identified. This was further supported by results from density functional theory calculations. The reaction energy of nitrogen fixation was quantitatively estimated and compared by building oxygen-enriched and anoxic models, where the change in the oxygen vacancy concentration was found to play a critical role in determining the nitrogen fixation performance. Results from this study suggest that Bi5O7Br with rich oxygen vacancies can be used as a high-performance photocatalyst for nitrogen fixation.
研究领域:
材料科学
·
环境科学
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催化化学
✓ 已验证
DOI
PubMed
高影响因子
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