SEPARATION AND PURIFICATION TECHNOLOGY
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2022
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IF 9.136
Xiaoyan Li,Rui Zhao,Hongfang Li,Jing Jiang,Lunhong Ai,Xuejuan Cao,Juanli Liu,Hanjun Zou,Youyu Duan
Suffering from inefficient separation and transfer of photogenerated carriers, the deeply photocatalytic oxidation of NO-to-NO 3 – over g-C 3 N 4 is still a daunting challenge. Well-designed heterojunction photocatalysts have been proven to be effective in steering charge transfer for achieving a particular migration path and more active sites, which hold huge promise in further performance stimulation. Herein, in-situ face-to-face hydrothermal approach is developed to prepare a multilayer heterostructure O doping g-C 3 N 4 (O-g-C 3 N 4 ) with W 18 O 49 (O-g-C 3 N 4 @W 18 O 49 ). The experimental and theoretical results show that the unique multilayer heterostructure can improve the separation efficiency of carriers by changing the electron migration path. Moreover, doping O atoms are identified as the newly formed active centers to largely facilitate the activation of NO. Impressively, the O-g-C 3 N 4 @W 18 O 49 photocatalyst thus exhibits largely improved photocatalytic NO removal rate (56.7 %, 0.1 g of sample) and high selectivity of NO to NO 3 – (98.3 %). It outperforms the reported photocatalysts materials in visible light. This study not only provides a facile strategy for experimentally screening advanced photocatalytic materials, but also paves the way for the deep oxidation of NO.
研究领域:
材料科学
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环境科学
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催化化学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
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IF 13.3
Zhijian Xiao,Wenda Yang,Jing Wang,Shuang Cao,Jingling Yang,Mingshan Zhu
Photocatalysis is a promising technology for removing low concentrations of nitric oxide (NO) from the atmosphere. However, the unsatisfactory photocatalytic NO removal efficiency and the high selectivity for NO 2 in catalysts limit the development of this technology. In this work, we used an in-situ synthesis method to incorporate Cs 3 Bi 2 Br 9 into UiO-66 for efficient and robust photocatalytic NO removal. The Cs 3 Bi 2 Br 9 /UiO-66 catalyst exhibits a 77.6 % NO removal efficiency and low NO 2 selectivity under visible light irradiation at a WHSV of 1,650,000 mL h −1 g −1 , exceeding the efficiencies of Cs 3 Bi 2 Br 9 (36.4 %) and UiO-66 (2.3 %), as well as those of most reported MOF-based photocatalysts. The synergy of weak Lewis acid sites from Cs 3 Bi 2 Br 9 in Cs 3 Bi 2 Br 9 /UiO-66 and the strong Lewis acid sites from UiO-66 promotes the enrichment of NO on the catalyst surface and act as electron traps to induce carrier separation, thereby promoting the generation of O 2 − to achieve high efficiency. This work provides a new idea for the development of catalysts in NO elimination.
研究领域:
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
JOURNAL OF ALLOYS AND COMPOUNDS
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2023
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IF 6.2
Tarek A. Gad-Allah,Ruiyang Zhang,Yi Wang,Ying Zhou
Various factors control the photocatalyst efficiency including the lifetime of photogenerated charge carriers, photocatalyst surface energy, and light harvesting efficacy. In this study, the defective (001)-TiO 2 -x/h-BN composite was synthesized by a facile one-pot method to merge the fantastic features of the reactive metastable (001) facet and self-defects in TiO 2 anatase crystals with the 2D h-BN. Pure anatase phase of TiO 2 was obtained by the suggested preparation method, which contains ∼33 % of the exposed (001) facet. The predominancy of oxygen vacancy in TiO 2 crystals was proved experimentally and theoretically by the DFT calculations. The defects in TiO 2 along with the incorporated h-BN caused better light harvesting and longer charge lifetime. The prepared defective (001)-TiO 2 -x/h-BN was applied efficiently for NO removal with very limited release of the toxic NO 2 by-product as an environmental application. The detected oxygen vacancy in TiO 2 along with h-BN were found to play a synergistic enhancement for NO removal. However, more defects reduced the overall activity because of rapid oxidation of oxygen vacancies on surface of the photocatalyst. To sum up, the defective (001)-TiO 2 -x/h-BN composite can be considered as a promising material for environmental applications.
研究领域:
环境科学
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材料科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 43
·19974-19982
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IF 3.3
Hao Fan,Qin Peng,Zhenxing Shen,Xuefeng He,Yiming Yang
Nitric oxide (NO), a major atmospheric pollutant and a precursor to haze, can be removed using the denitration catalyst. Mn and Ni are commonly used as denitration catalyst additives owing to their adsorption abilities for NO and ammonia (NH3). In this study, we synthesized Mn- and Ni-loaded Pt-modified sulfated cerium oxide (PtSCe) catalysts using an impregnation method and explored the effects of these elements. The results revealed that the two elements had contrasting effects on the denitration activity of the catalysts. Mn improved the water vapor and sulfur resistance of the PtSCe sample by increasing the concentration of weak acid sites, enhancing the redox ability, and increasing the content of surface-adsorbed oxygen. The elevation in oxygen vacancies, stimulated by the presence of Ce3+ and Mn3+, swiftly replenished the reactive oxygen species, thereby sustaining the high denitration efficiency of the MnPt/SCe sample. Active sites on the catalyst surface included NH3 adsorbed on Lewis acid sites, NH4+, and –NH2, along with bridging, monodentate, and bidentate nitrate groups. Regarding the catalyst reaction mechanism, we determined that the selective catalyst reduction of NH3-SCR over MnPt/SCe followed both the Eley–Rideal and Langmuir–Hinshelwood mechanisms. These findings offer crucial insights into the intricate relationship between metals, sulfates, and carrier molecules, thus providing implications for future catalyst design.
研究领域:
环境科学
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催化化学
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产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Zhihui Hu,Huanmin Liu,Ningxin Kang,Kangle Lv,Qin Li
Using solvothermal methods to in situ oxidize two-dimensional titanium carbide (Ti 3 C 2 T x ) MXene into TiO 2 nanocrystals offered an effective strategy to construct highly efficient TiO 2 /Ti 3 C 2 T x heterojunctions for photocatalytic applications. Nevertheless, the effect of the chosen solvent on the Ti 3 C 2 T x oxidation and the product's performance was often neglected. Herein, isopropanol (ISO), ethanol (EtOH), ethylene glycol (EG), dimethyl sulphoxide (DMSO) and deionized water (Water) were taken as the representative solvents to prepare TiO 2 /Ti 3 C 2 T x composites by one-step solvothermal method for photocatalytic NO emission. It was the large polarity, dielectric constant and surface tension of the solvents that offered Ti 3 C 2 T x with good dispersibility and high oxidation degree during the solvothermal process. More importantly, the solvothermal treatment of Ti 3 C 2 T x in DMSO could promote the formation of TiO 2 nanoparticles with obviously higher crystallinity and more surface oxygen vacancies than those in EG, EtOH and ISO. Therefore, the photocatalytic NO oxidation efficiency of the samples within 30-min irradiation showed a descending order of TT-DMSO (46.9%), TT-Water (42.2%), TT-EG (32.3%), TT-EtOH (26.7%), and TT-ISO (19.9%). This work highlighted the significance of oxidation environment for Ti 3 C 2 T x , which could bring about some new but necessary consideration on the processing technique of MXene families for their future practical applications.
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
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2020
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IF 7.489
Beibei Wang,Dongyun Chen,Najun Li,Qingfeng Xu,Hua Li,Jinghui He,Jianmei Lu
We report an unique 2D/2D Iodine doped BiOIO 3 /g-C 3 N 4 heterojunction was successfully prepared. The iodine doped BiOIO 3 was prepared by a simple solvent exchange method and combined with g-C 3 N 4 by solvothermal method . The prepared photocatalyst has potential application value in the future due to its excellent stable cycle property. BiOIO 3 nanoplates and g-C 3 N 4 nanosheets form a close interfacial contact directly, so the catalyst has higher charge transport efficiency and wide visible range due to the introduction of iodide ions. Synergistic heterojunction exhibits strong photocatalytic activity for degradation of NO at ppb-level under visible light , of which 30% Iodine doped BiOIO 3 /g-C 3 N 4 can achieve a maximum removal rate of 57% for NO. According to the experimental results of ESR and other experiments, a more complex Z-scheme photocatalytic mechanism is proposed, which has stronger redox ability than the traditional mechanism.
研究领域:
环境科学
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材料科学
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产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
·
IF 14.229
Wen Cui,Lvcun Chen,Jieyuan Li,Ying Zhou,Yanjuan Sun,Guangming Jiang,S.C. Lee,Fan Dong
Semiconductor-based photocatalysis has attracted considerable interdisciplinary attention for its diverse applications in environmental remediation and solar energy conversion. However, pure earth-abundant insulators have been seldom considered as photocatalysts because of the unfeasible electronic excitation. In this work, we make the earth-abundant insulator BaSO 4 as conceptually new photocatalyst via Ba-vacancy engineering for the first time. The BaSO 4 with Ba-vacancy is synthesized by a facile precipitation method and applied for photocatalytic NO removal in air. XAFS spectroscopy and DFT calculations demonstrate the formation of Ba-vacancy. Also, defect level induced by Ba-vacancy between the wide band gap is demonstrated, which endows insulator BaSO 4 with semiconductor-like photocatalytic performance. Besides, according to the TPD analysis and theoretical simulation, Ba species is functioned as the NOx storage center for the primary accumulation of NO molecule on substrate, and simultaneously Ba-vacancy is equipped with the capability to redistribute charge carriers and thus accelerate the activation of NO molecule by the donation of electrons to electron-deficient areas, facilitating the conversion of NO into a higher valance state for further favorable photocatalytic oxidation. In situ DRIFTS spectra are applied to dynamically monitor intermediates and products on photocatalyst surface, revealing the reaction process and the enhancement role of Ba-vacancy. This work opens a new research doorway on earth-abundant insulators for the development of a new family of photocatalyst.
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
ENVIRONMENTAL RESEARCH
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2025
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IF 7.7
Huasheng Wang,Shuang Deng,Hongyun Hu,Can Fang,Guangqian Luo,Ze Wang,Songgeng Li
Excessive ClO 2 tends to be produced and escape, causing secondary pollution when wet oxidation of NO with NaClO 2 is conducted under acidic conditions. NaClO 2 alkaline oxidation has accordingly received a wide attention. In this work, NaClO 2 alkaline oxidation of NO has been systematically studied in a self-built spray tower. Focus has been placed on the effects of acidic components contained in flue gas such as CO 2 , HCl and SO 2 . ClO 2 and HClO 2 are considered more effective for NO oxidation, which tend to be produced in an acidic environment. HCO 3 − has a relatively higher hydrolysis coefficient than ClO 2 − , leading to more HClO 2 formation. Similarity is found with HCl although the effect is not as significant as CO 2 due to its low concentration in flue gas. SO 2 exhibits a negative effect on NO removal since HClO 2 can be consumed by SO 2 . Nearly 100 % NO removal efficiency can be achieved although there is an initial time delay necessary for the neutralization of alkaline environment. A similar performance has been observed for HCl. On the contrary, SO 2 exhibits a negative effect on NO removal due to the competition with NO in the consumption of NaClO 2 . Additives such as NaClO and CTAC were also used to enhance NaClO 2 alkaline oxidation performance. Interesting to note that CTAC can nearly eliminate the time delay by intensifying the gas-liquid mass transfer.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2025
·
IF 6.3
Jiahe Zhai,Hui Wang,Abdelkader Labidi,Long Zeng,Yu Huang,Chuanyi Wang
Removing low-concentration NO in the air by means of photocatalytic technology is a promising approach. Herein, our work pins down the mechanism of cobalt metal doping within the lattice of Bi 4 Ti 3 O 12 (BTO) for the photocatalytic NO conversion. As a result, the Co-BTO exhibits a NO conversion efficiency of 58.3 %, which is substantially higher than that of BTO (30 %). More interestingly, the Co-BTO also shows a lower production of intermediate NO 2 than that of the BTO. These findings demonstrate that within Co-BTO, both Co²⁺ and Co³ ⁺ coexist. The redox cycle between these two cobalt species engenders active sites possessing strong reducing capabilities for O₂ which can be adsorbed and activated at the Co sites, thereby generating superoxide radicals (•O₂⁻). Furthermore, the doping of a certain portion of cobalt broadened light absorption and enhanced the separation efficiency of photogenerated carriers, further facilitating the activation of O₂. Lastly, electron spin resonance (ESR) and in-situ diffuse reflective infrared Fourier transform spectroscopy (in-situ DRIFTS) were respectively utilized to further clarify the active species involved in the photocatalytic oxidation of NO and its adsorption and conversion pathways from a mechanistic standpoint. Overall, this work represents a novel endeavor for the advancement of visible-light-driven photocatalysts usage for environmental remediation against NO pollution.
研究领域:
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
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Liwei Ma,Shihua Zheng,Guoqiang Li,Xuejun Wang,Kangdi Chen,Guojie Zhang
Fe(II)EDTA can remove NO efficiently, but it has not been industrially applied. This is because the oxygen present in the flue gas will oxidize Fe(II)EDTA and Fe(II)EDTA-NO to Fe(III)EDTA and deactivate them. In order to solve this problem, this paper innovatively proposes to use NaHS to reduce Fe(III) EDTA, because NaHS has high reducing ability and low price. Therefore, a series of experimental conditions were explored in order to obtain the best reaction setup. The results indicate that increasing the concentrations of NaHS, temperature, and pH enhances the rate of NaHS reduction. The mechanism of the increase in reduction rate was studied in depth using potentiometric titration. It was found that an increase in OH - concentration will generate S 8 precipitate, which is beneficial to the forward progress of the reaction and promotes the large-scale production of the active component Fe 2+ . Oxygen is an inevitable factor in actual flue gas, so this study innovatively proposed a kinetic model under aerobic conditions and used this model to predict the trend of Fe(III)EDTA reduction by NaHS. On this basis, NO removal experiments were conducted under high oxygen conditions. After 15 cycles, the reduction performance of NaHS was still very high, and the NO removal rate was higher than 70%. The reason for this phenomenon is that the stabilizer exists in a form that is conducive to the removal of NO by the active component Fe 2+ . Therefore, this study provides theoretical guidance for promoting the industrial application of Fe(II) EDTA technology for NO removal.
研究领域:
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Hongxia Liu,Minggang Zhang,Zhipeng Jin,Hui Mei,Gangqiang Zhu,Longkai Pan,Laifei Cheng,Litong Zhang
Photocatalysis is recognized as one of the most promising techniques for environment purification. However, the inconvenient recovery of powder photocatalysts significantly impeded their practical applications. Immobilization of the photocatalysts on supports to form monolithic photocatalysts is an effective method to solve this problem. Herein, a monolithic photocatalyst Bi 12 TiO 20 /Bi 4 Ti 3 O 12 /SiOC is fabricated by growing optimal Bi 12 TiO 20 /Bi 4 Ti 3 O 12 S-scheme heterojunction onto 3D-printed porous SiOC support. On one side, S-scheme heterojunction facilitates the separation of photoinduced electrons and holes while retaining their strong redox ability. On the other side, the porous structure favors mass transport and improves light harvesting by reflecting the light several times. Under simulated solar light irradiation, the NO removal efficiency of the monolithic photocatalyst Bi 12 TiO 20 /Bi 4 Ti 3 O 12 /SiOC is 16.4 %. Furthermore, the composite has good stability and reusability, suggesting its great potential in practical application. The possible photocatalytic mechanism is proposed according to systematic experiments and density functional theory (DFT). This work provides a rational reference for constructing efficient photocatalysts for environmental purification.
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
ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Zhenyu Wang,Yu Huang,Meijuan Chen,Xianjin Shi,Yufei Zhang,Junji Cao,Wingkei Ho,Shun Cheng Lee
The development of catalysts that effectively activate target pollutants and promote their complete conversion is an admirable objective in the environmental photocatalysis field. In this work, graphitic carbon nitride (g-C3N4) microtubes with tunable N-vacancy concentrations were controllably fabricated using an in situ soft-chemical method. The morphological evolution of g-C3N4, from the bulk to the porous tubular architecture, is discussed in detail with the aid of time-resolved hydrothermal experiments. We found that the NO removal ratio and apparent reaction rate constant of the g-C3N4 microtubes were 1.8 and 2.6 times higher than those of pristine g-C3N4, respectively. By combining detailed experimental characterization and density functional theory calculations, the effects of N-vacancies in the g-C3N4 microtubes on O2 and NO adsorption activation, electron capture, and electronic structure were systematically investigated. These results demonstrate that surface N-vacancies act as specific sites for the adsorption activation of reactants and photoinduced electron capture, while enhancing the light-absorbing capability of g-C3N4. Moreover, the porous wall structures of the as-prepared g-C3N4 microtubes facilitate the diffusion of reactants, and their tubular architectures favor the oriented transfer of charge carriers. The intermediates formed during photocatalytic NO removal processes were identified by in situ diffuse reflectance infrared Fourier transform spectroscopy, and different reaction pathways over pristine and N-deficient g-C3N4 are proposed. This study provides a feasible strategy for air pollution control over g-C3N4 by introducing N-vacancy and porous tubular architecture simultaneously.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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