Journal of Central South University
·
2015
·Vol. 22
·期 3
·868-873
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IF 0.52
Qin Wen-qing,Luo Hong-lin,Liu Wei,Zheng Yong-xing,Yang Kang,Han Jun-wei
The volatilization of stibnite (Sb 2 S 3 ) in nitrogen from 700 to 1000 °C was investigated by using thermogravimetric analysis. The results indicate that in inert atmosphere, stibnite can be volatilized most efficiently as Sb 2 S 3 (g) at a linear rate below 850 °C, with activation energy of 137.18 kJ/mol, and the reaction rate constant can be expressed as k =206901exp(−16.5/ T ). Stibnite can be decomposed into Sb and sulfur at temperature above 850 °C in a nitrogen atmosphere. However, in the presence of oxygen, stibnite is oxidized into Sb and SO 2 gas at high temperature. Otherwise, Sb is oxidized quickly into antimony oxides such as Sb 2 O 3 and SbO 2 , while Sb 2 O 3 can be volatilized efficiently at high temperature.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Yingshu Wang,Shuyue Wang,Jiasi Gan,Jinni Shen,Zizhong Zhang,Huidong Zheng,Xuxu Wang
One-pot synthesis of urea [(NH2)2CO] from easily available small molecules, that is, N2, CO2, and H2O, is an extremely attractive but very challenging reaction. 2D-CdS@3D-BiOBr composites with S-scheme heterojunctions are constructed via a facile hydrothermal technique followed by a self-assembly method and shown to be an excellent photocatalyst enabling the reduction of N2 and CO2 with H2O to (NH2)2CO under visible light. The optimal 40%2D-CdS@3D-BiOBr sample shows up to 15 μmol·g–1·h–1 total yield of NH3 and (NH2)2CO, of which (NH2)2CO accounts for 54%. The apparent quantum efficiency (AQE) is 3.93% for urea production. On the photocatalyst, urea is speculated to form by two possible chemical routes. One is direct photocatalytic synthesis. Both N2 and CO2 molecules are activated by the Cd2+ ion of 2D-CdS and the oxygen defect of 3D-BiOBr at the edges of the heterojunction interface of 2D-CdS/3D-BiOBr, respectively. *HNCONH* is the key intermediate of the formation of (NH2)2CO molecules. The other is indirect synthesis by photocatalysis and then thermocatalysis. N2 is reduced into NH3 and CO2 is reduced into CO on 2D-CdS by the photogenerated electrons and protons, and then the formed NH3 reacts with the reactant CO2 or the product CO to form (NH2)2CO by thermocatalysis on 2D-CdS. The former is dominant for urea synthesis. The work confirms that urea could be synthesized photocatalytically from cheap N2, CO2, and H2O under visible light. A composite heterojunction semiconductor could be a prospective photocatalyst appropriate for the complex reaction.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Bo Xu,Zaichun Liu,Weibin Qiu,Qian Liu,Xuping Sun,Guanwei Cui,Yuping Wu,Xiaoli Xiong
Identification of new effective and selective N 2 reduction electrocatalyst is still of critical importance for fundamental and application research. Here, we report La 2 O 3 nanoplate performing as an efficient metal oxide catalyst for electrochemical N 2 fixation to NH 3 , which exhibits excellent selectivity and stability with a high Faradaic efficiency of 4.76% and a NH 3 yield rate of 17.04 μg h −1 mg −1 cat. at −0.8 V vs. reversible hydrogen electrode (RHE) in 0.1 M Na 2 SO 4 solution under atmospheric pressure. Density functional theory (DFT) calculation results show that La atoms in La 2 O 3 act as the active sites for efficiently adsorbing N 2 . The optimal adsorption approach of N 2 molecule on the (011) face of La 2 O 3 is end-on-two configuration which is highly activated. Thus La 2 O 3 exhibits high performance for electrochemical reduction of N 2 .
研究领域:
电化学
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催化
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材料科学
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理论化学
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产品关联
DOI
高影响因子
CHEMOSPHERE
·
2023
·
IF 8.8
Le Zhang,Yong Liu,Jianlong Wang
The oxidation of ammonium (NH 4 + ) to dinitrogen (N 2 ) with high selectivity and high efficiency is still a challenge. Herein, a novel sunlight induced persulfate (PS)-based AOPs process (MgO/Na 2 SO 3 /PS/ hv ) was proposed by introducing solid base (MgO) and hydrated electron (e aq − ), to selectively oxidize NH 4 + to N 2 , with high selectivity and high efficiency at a wide range of pH value. The deprotonation of NH 4 + into NH 3 by MgO and the generation of •OH and SO 4 −• by PS activation were responsible for the high efficiency of NH 4 + oxidation. The buffering capacity provided by MgO to proton released from PS activation made the NH 4 + oxidation possible at a wide pH range. The e aq − from the Na 2 SO 3 / hv process was the main active specie to reduce NO 2 − and NO 3 − (NO x − ) into N 2 , responsible for high N 2 selectivity of NH 4 + oxidation. 100% NH 4 + could be oxidized within 30 min, and N 2 selectivity exceeded 96% at the initial pH range of 3–11 and the initial concentration of NH 4 + of 30 mg N/L. This work could offer an efficient AOPs process for selective NH 4 + oxidation, which is promising for the chemical denitrification of wastewater ….
研究领域:
环境科学
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化学工程
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2024
·
IF 9.4
Cheng Liu,Qi Chen,Yueling Chen,Jimmy C. Yu,Jionghua Wu,Ling Wu
Photocatalysis, which uses sunlight, N 2 and H 2 O to produce NH 3 , is a more sustainable approach to N 2 fixation than the Haber-Bosch process. However, its efficiency is severely limited by the difficulty of activating N N bonds. This work presents metal (M = Cu, Fe, V)-substituted MIL-125(Ti) (MIL-(MTi)) for photocatalytic N 2 fixation without using any sacrificial agents. Structural characterizations reveal that the active sites including oxygen vacancies (OV) and Ti 3+ species are formed by the resulting crystal distortion due to the partial substitution of Ti 4+ by other metal ions (Cu + , Fe 2+ , V 3+ ) in MIL-125(Ti). MIL-(CuTi) possesses a larger number of OV and Ti 3+ compared to MIL-(FeTi) and MIL-(VTi) due to the larger valence difference between Cu + and Ti 4+ . These active sites not only promote the adsorption and activation of N 2 and H 2 O, but also facilitate the photogenerated charge mobility. Photogenerated holes oxidize H 2 O to produce O 2 and H + . Photogenerated electrons reduce N 2 activated on Ti 3+ sites by combining with H + to form NH 4 + . Therefore, MIL-(CuTi) shows the highest NH 4 + production rate 46.5 µmol·h −1 ·g −1 , which is much higher than that (1.2 µmol·h −1 ·g −1 ) of the pristine MIL-125(Ti). This work provides a new insight into rational design for artificial N 2 fixation systems by the construction of the active site.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Chemistry-An Asian Journal
·
2020
·Vol. 15
·期 8
·1272-1276
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IF 4.056
Yueming Cao,Peipei Li,Tengteng Wu,Meiling Liu,Youyu Zhang
Graphical HKUST-1 (Cu−BTC, BTC=benzene-1,3,5 tricarboxylate) was selected as an electrocatalyst for the reaction of conversion N 2 to NH 3 under ambient conditions. At −0.75 V vs. reversible hydrogen electrode, it achieves excellent performance with high NH 3 yield (46.63 μg h −1 mg −1 cat. or 4.66 μg h −1 cm −2 ) and Faraday efficiency (2.45%). Electrolytic ammonia synthesis from nitrogen at ambient conditions is appearing as a promising alternative to the Haber-Bosch process which is consuming high energy and emitting CO 2 . Here, a typical MOF material, HKUST-1 (Cu−BTC, BTC=benzene-1,3,5-tricarboxylate), was selected as an electrocatalyst for the reaction of converting N 2 to NH 3 under ambient conditions. At −0.75 V vs. reversible hydrogen electrode, it achieves excellent catalytic performance in the electrochemical synthesis of ammonia with high NH 3 yield (46.63 μg h −1 mg −1 cat. or 4.66 μg h −1 cm −2 ) and good Faraday efficiency (2.45%). It is indicated that the good performance of the HKUST-1 catalyst may originate from the formation of Cu(I). In addition, the catalyst also has good selectivity for N 2 to NH 3 .
研究领域:
材料科学
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电化学
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催化反应
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 10
·13396-13408
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IF 2.478
Zhao Guoqing,Zou Jiao,Liu Lukai,Hu Jun,Yu Jingang,Jiao Feipeng
Direct fixation of nitrogen (N 2 ) to ammonia (NH 3 ) under ambient conditions via photocatalysts is a promising method to relieve the pressure of energy shortage, where chemisorptions of torpid nitrogen and delivery of photoproduced electrons to N≡N bond are recognized technical limitations. In this work, we have developed the catalysts of NiFe-LDH-derived sulfides microspheres ([NiFe]S) with excellent photocatalytic activity for reduction of N 2 to NH 3 . Excitingly, the NH 3 generation rates of [NiFe]S catalysts reached up to 111.83 μmol · L −1 · h −1 under visible light irradiation in water, which were 10.35 times than that of NiFe-LDH microspheres. The reason was due to the higher photo-induced carrier separation and transmission efficiency of [NiFe]S microspheres. In addition, the possible photocatalytic mechanism was proposed. This new work could guide the design of efficient catalysts and open up the application of metal sulfides in photocatalytic N 2 fixation.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2015
·
IF 2.037
Yu Zhang,Wei Su,Yan Sun,Jia Liu,Xiuwu Liu,Xiaojing Wang
MIL-101 is a promising adsorbent because of its large pore volume, high separation selectivity, easy regeneration, and good stability. MIL-101 was synthesized and characterized by X-ray diffraction, scanning electron microscopy, and nitrogen adsorption at 77 K. Adsorption isotherms of pure N2, CH4, and CO2 were measured on MIL-101 from 263 K to 313 K and at pressures up to 0.8 MPa. The Langmuir model was a good fit for the experimental isotherms and the isosteric heats of adsorption decreased in the order: CO2 > CH4 > N2. The CO2/CH4 separation selectivity was sensitive to the adsorption pressure and temperature and it varied from 3.2 to 6.3. In contrast, the CH4/N2 separation selectivity changed from 2.6 to 3.3 with temperature and pressure.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Jiao Hu,Tiantian Zhao,Xue Li,Guangzhi Hu
The electrocatalytic conversion of nitrate (NO 3 − ) to nitrogen (N 2 ) is a promising strategy for addressing the global issue of NO 3 − pollution in surface water and groundwater. However, the scarcity of efficient denitrification catalysts hinders the development of the aforementioned process, particularly at low NO 3 − concentrations. Herein, a self-supporting array of defect-rich heterostructured nanowires (Ni 0.8 Cu 0.2 O@CuO@NF) was synthesized for highly selective reduction of NO 3 − to N 2 . The introduction of Cu accelerated the rate-limiting step (NO 3 − to NO 2 − ), and the presence of defect-rich heterojunctions increased the catalytic active sites of the catalyst, thereby accelerating the reduction of NO 3 − and improving the selectivity towards N 2 . Ni 0.8 Cu 0.2 O@CuO@NF exhibited excellent denitrification capacity, with approximately 100% of NO 3 − degradation and 99.9% of N 2 selectivity under optimum parameter conditions, as well as ultra-high stability during the 8-cycle test. Significantly, NO 3 − conversion and N 2 selectivity for actual wastewater with complex ingredients were 70.7% and 99.1%, respectively. This study presents a novel concept for the development of cost-effective and highly effective catalysts for water and environmental restoration.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2022
·
IF 5.436
Qiang Xian,Xin Xiao,Jiaping Yu,Yi Gan,Li Chen,Xinmiao He,Enchao Wang,Hui Dan,Lin Zhu,Yi Ding,Tao Duan
The immobilization of iodine waste suffers from serious iodine loss during heat treatment. Herein, we reported on the high iodine retention immobilization of simulated radioiodine-contaminated Bi0–SiO2 sorbent in B–Bi–Zn oxide glass using Bi2O3 as a stabilizer under a N2 atmosphere. The effects of the Bi2O3 content and sintering atmosphere on the iodine immobilization behaviors (iodine retention ratio, phase composition, microstructure, and chemical stability) were investigated. It was found that the decomposition of BiI3 was prevented by adding Bi2O3 and sintering in a N2 atmosphere. The iodine retention ratio in the obtained glass waste form was significantly enhanced with increasing Bi2O3 content and sintering in the N2 atmosphere due to the synergistic effect. The achieved record-high iodine retention (92.22 ± 2.6%) was much higher than that of conventional heat treatment route (18.01 ± 3.5%). The results demonstrated that iodine was effectively immobilized through the formation of stable BixOyI (Bi5O7I and BiOI). Furthermore, the obtained iodine waste form exhibited excellent compactness and chemical stability. Owing to its high iodine retention ratio, this route can be employed to effectively immobilize radioactive iodine.
研究领域:
材料科学
·
核废料管理
✓ 已验证
DOI
高影响因子
ACS Catalysis
·
2019
·
IF 12.221
Yan Liu,Xiangdong Kong,Xu Guo,Qiuyao Li,Jingwen Ke,Ruyang Wang,Qunxiang Li,Zhigang Geng,Jie Zeng
Electroreduction of N2 into NH3 represents a promising method for N2 fixation. However, due to the inertness of N≡N covalent triple bonds, this process remains a huge challenge to achieve a high yield rate of NH3. In this work, we designed an effective approach to promoting N2 activation by introducing oxygen vacancies into LaCoO3. In N2 electroreduction, LaCoO3 with oxygen vacancies (denoted as Vo-LaCoO3) exhibited a Faradaic efficiency of 7.6% for NH3 at −0.6 V versus the reversible hydrogen electrode (RHE). Notably, at −0.7 V versus RHE, the yield rate for NH3 of Vo-LaCoO3 reached 182.2 μgNH3 mg–1cat. h–1, which was 2.8 times higher than that (65.3 μgNH3 mg–1 h–1) of pristine LaCoO3. To the best of our knowledge, the yield rate for NH3 of Vo-LaCoO3 approaches the activities of the state-of-the-art catalysts toward N2 electroreduction. Density functional theory calculations revealed that enhanced activation of N2 over Vo-LaCoO3 originated from the increased charge density around the valence band edge via the introduction of oxygen vacancies. Furthermore, the analysis of the thermodynamic limiting potentials for N2 reduction and H2 evolution demonstrated the higher selectivity for N2 electroreduction over Vo-LaCoO3 relative to pristine LaCoO3.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
ACS ES&T Engineering
·
2024
·
IF 7.4
Hanling Jiang,Jingwen Wang,Aijuan Zhou,Yong Liu
Advanced oxidation processes (AOPs) for removing ammonia nitrogen (NH4+-N) are of increasing interest in wastewater treatment. In this paper, the UV-activated persulfate (PS) process with CaO was applied to oxidize NH4+-N to nitrogen gas (N2). Nearly all of the NH4+-N (30 mg N/L) could be removed within 15 min, and the N2 selectivity was achieved at 95.0%. The addition of CaO made NH4+-N exist in the form of NH3, and HO• was the critical reactive species for NH4+-N oxidation. NO, N2H4, and NO2– were identified as oxidation intermediates and could be further removed. The reaction between N2H4 and NO2– with the assistance of UV/CaO promoted N2 generation during NH4+-N oxidation. The increased dosages of CaO (0.2 to 4.0 g/L) and PS (0.6 to 2.4 g/L) could enhance the NH4+-N oxidation, while the presence of CO32– (100 mM) significantly retarded the removal of NH4+-N. As high removal of NH4+-N (100%) and high N2 selectivity (>79.5%) could be achieved in lake water and secondary wastewater, the proposed UV/PS/CaO process could be potentially applied for the oxidation of NH4+-N in practical water treatment.
研究领域:
环境科学
·
废水处理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）