ACS Applied Nano Materials
·
2024
·
IF 5.3
Baoshan Teng,Chunhui Ma,Jiayu Chen,Yunlai Zhang,Baohuan Wei,Maohai Sang,Hui Wang,Yuhan Sun
Ammonia is recognized as the best carrier for hydrogen storage and transportation. Nanomaterial catalysts have eminent catalytic activity for ammonia decomposition. However, the preparation of low-loading, high-activity noble metal atomically dispersed nanometer ammonia decomposition catalysts and their reaction mechanisms remain obscure. In this work, we report the synthesis of a stable ruthenium (Ru) atomically dispersed catalyst with oxygen-rich defects achieved through hydrogen etching of the support CeO2NR nanorods. The oxygen defects result in the catalyst exhibiting a favorable low-temperature catalytic activity and an exceedingly high atom utilization rate for ammonia decomposition. The hydrogen production rate from ammonia decomposition per unit mass of Ru is as high as 2446 mmol H2 gRu–1 min–1 at 1 bar, 450 °C, and gas hour space velocity = 12,000 mL gcat–1 h–1. In this case, the highly dispersed Ru provided enough active sites, while the oxygen defects of the catalyst enhanced the electron transfer tunnel between Ru and the nanorod support under a Schottky contact model. The detailed mechanism of oxygen defects for improving the catalytic performance of ammonia decomposition was studied by DFT modeling. Thus, this work provides a promising strategy to improve the catalytic efficiency of an atomically dispersed Ru nanocatalyst.
研究领域:
材料科学
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催化化学
·
理论化学
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2022
·
IF 14.224
Wen Xie,Guangyan Xu,Yan Zhang,Yunbo Yu,Hong He
A mesoporous LaCoO 3 perovskite oxide (LaCoO 3 -Meso) with three-dimensionally ordered helical interwoven structure was synthesized by a nano-casting method using KIT-6 as the hard template. The obtained LaCoO 3 -Meso with high surface area was tested for its catalytic performance in the NO x storage and reduction (NSR) reaction and compared with a sample synthesized by the conventional sol-gel method. The LaCoO 3 -Meso showed a significant advantage for NO x storage, with a NO x storage capacity 2 times higher than the regular sample. LaCoO 3 -Meso also exhibited improved NSR catalytic performance in the 150–450 °C temperature range, especially within 350–400 °C, where the NO x conversion was raised for 40%. The results of X-ray photoelectron spectroscopy and X-ray absorption fine structure measurements suggested the presence of a high concentration of oxygen defects on the LaCoO 3 -Meso surface. Further results provided by temperature programmed reduction and temperature programmed desorption indicated that the oxygen defects not only increase the amount of trapped NO x , but also improve the low-temperature redox performance of the catalyst. The lower stability of NO x species adsorbed on oxygen defects promotes the NO x release step in the NSR reaction and benefits the regeneration of storage sites.
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
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Yu Qiu,Zhihao Sun,Zihao Guo,Jingyu Bi,Guangshen Li,Lei Qian
Herein, oxygen-deficient NH 4 V 4 O 10 micro-flowers with loaded Ag quantum dots and pre-intercalated Ag + (NVO-Ag) for aqueous zinc ion battery (AZIB) cathode materials were successfully synthesized by a one-step hydrothermal method. The reversible redox reaction between Ag + and Ag quantum dots, and the abundant Zn 2+ storage sites from oxygen vacancies provided capacity contributions for NVO-Ag. Meanwhile, the loaded Ag quantum dots, pre-intercalated Ag + and introduced oxygen vacancies synergistically optimized the electronic structure and distribution of NVO-Ag, promoting the transport of electrons in NVO-Ag. The pre-intercalated Ag + could also replace the NH 4 + in the interlayer of NH 4 V 4 O 10 , weakening the repulsion between the interlayer NH 4 + and Zn 2+ , which achieved rapid Zn 2+ diffusion kinetics. Moreover, the abundant oxygen vacancies in NVO-Ag could alleviate the strong electrostatic interaction between Zn 2+ and V-O framework, boosting the transmission of Zn 2+ in NVO-Ag. Finally, the structural stability of NH 4 V 4 O 10 micro-flowers was improved due to the high bonding strength between Ag + and V-O layers. Benefiting from the above effects, NVO-Ag-100 achieved excellent capacity performance (387.2 mAh g −1 at 0.5 A g −1 ), rate performance (178.9 mAh g −1 at 12 A g −1 ) and cycle stability (91.7 % capacity retention after 1700 cycles at 8 A g −1 ). This work provided effective ideas to achieve high-performance AZIB cathode materials.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Yu Guan,Yinhe Liu,Qiang Lv,Bo Wang
The selective catalytic reduction of nitrogen oxides (NO x ) by carbon monoxide (CO-SCR) is a promising way to deal with exhaust gasses. And Effective redox cycle and NO dissociation ability are crucial factors for catalytic reduction of NO x . Herein, Fe decorated CeO 2 microsphere catalysts with surface oxygen defect were synthesized by solvothermal and calcination method. Among all catalysts, 0.5Fe-CeO 2 sample showed excellent catalytic performance with efficiency near 96% for NO reduction under the condition of 550 ppmv NO, 1200 ppmv CO, and 40,000 h − 1 of GHSV. It was found that Fe doping could efficiently regulate Ce 4+ /Ce 3+ redox couple and oxygen vacancy for catalytic activity. XRD, Raman, XPS, EPR and H 2 -TPR etc. were employed to explore the physicochemical properties of samples. The results showed that Fe had been incorporated into CeO 2 by XRD, and the results of Raman spectrum and XPS indicated that Ce 4+ /Ce 3+ redox couple existed in 0.5Fe-CeO 2 catalyst. Furthermore, the H 2 -TPR spectrum displayed the formation of oxygen vacancy in the samples. N 2 adsorption-desorption isotherms indicated that the doping of Fe could enlarge the specific surface area, pore volume and pore dimeter of the samples, and thus greatly enhanced the NO adsorption and further NO catalytic reduction on catalysts. In addition, other characterization of physicochemical properties and density functional theory (DFT) calculation were performed to reveal the mechanism of NO + CO reaction. As a result, a mechanism was proposed to elucidate highly efficient NO reduction over the catalysts of Fe decorated CeO 2 microspheres. Finally, the synergistic effects of redox center and oxygen vacancy on catalytic activity enhancement were revealed. This work provides a promising way to the design of efficient catalysts for NO reduction.
研究领域:
催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2023
·Vol. 13
·期 7
·1078
·
IF 3.9
Ze Hong,Jingying Ouyang,Jiaxin Li,Han Zheng,Ying Liu
Multi-heterojunctions are more promising than single heterojunctions in photocatalysis due to the availability of more interfaces between each component. However, photocatalytic activity is highly dependent on the contact mode of individual components. In this work, we assembled gold nanoparticles/oxygen-deficient (anatase/B-phase) TiO2multi-heterojunction microspheres using spray pyrolysis and focused on their contact mode-governed photocatalytic activity. The results reveal that using oxygen-deficient (anatase/B-phase) TiO2microspheres as building blocks could significantly enhance the absorption of visible light and the photocatalytic activity of a gold–TiO2system toward the photocatalytic carbon monoxide oxidation. Furthermore, loading gold nanoparticles onto B-phase TiO2could facilitate a more prominent enhancement of activity than that of pure B-phase TiO2, benefiting from the two-electron reduction of oxygen at the interface of TiO2/Au. Meanwhile, the high crystallinity of B-phase TiO2microspheres allows for a gold loading amount of 1 wt% in the gold/(anatase/B-phase) TiO2system, which is 1.67 times more active than pure B-phase TiO2microspheres, in the photocatalytic oxidation of carbon monoxide to generate carbon dioxide.Keywords:photocatalytic carbon monoxide oxidation;B-phase TiO2;oxygen-deficient;microspheres
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Science China-Chemistry
·
2025
·
IF 9.7
Liang Li Ya,Wang Xiao Yuan,Gao Ya Ting,Wu Da Jun,Li Da Wei,Chen Bin Bin
Ordinary metal salts have become a promising afterglow material because of the characteristics of wide sources, low cost, and easy availability. However, their extremely weak afterglow efficiency makes them rarely used in practical applications. In this study, we proposed a ligand engineering strategy to greatly enhance the afterglow efficiency of metal salts. Al 2 (SO 4 ) 3 , as a typical metal salt, has only a photoluminescence quantum yield (PL QY) as low as 0.1% and an unmeasurable phosphorescent QY. After doping with dual organic ligands, the PL QY of Al 2 (SO 4 ) 3 has increased by nearly 200 times, reaching 19.90%. Meanwhile, the afterglow intensity of Al 2 (SO 4 ) 3 has increased by approximately 20 times, accompanied by a great increase in phosphorescent lifetime from 416.15 to 2870.08 ms (a about 7-time increase). The enhancement mechanism of afterglow efficiency is ascribed to the fact that the excited electrons from the dual ligands can be directly captured by oxygen defects (trap), then transferred to the emitters (Al 3+ ions), and ultimately achieving efficient afterglow luminescence. This study utilizes ligand engineering strategy to improve the afterglow luminescence efficiency of metal salts, achieving their applications in deep ultraviolet (UV)-excited light emitting devices and visual ethylene glycol recognition.
研究领域:
材料科学
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化学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2024
·
IF 8
Qiaoling Xing,Xujie Chen,Yong Cai,Ming Zhang
As a kind of green energy, hydrogen (H 2 ) has been widely concerned and applied by people. One of the biggest challenges for sensing applications is the quick detection of hydrogen leaks or their release in various conditions, particularly in large electric vehicle batteries. This study successfully constructed a quick response and recovery hydrogen sensor based on the In 2 O 3 -SnO 2 heterojunction. The response and recovery time of the In 2 O 3 -SnO 2 hydrogen sensor is 1.1/1.9 s to 50 ppm H 2 . This is reduced to 11.0 %/9.5 % compared to the SnO 2 hydrogen sensor. This sensor's remarkable gas detecting properties are mainly attributed to the In 2 O 3 -SnO 2 heterojunction creation, crystal structure modification, and increased specific surface area (92.9 m 2 /g). Homogenous In 2 O 3 -SnO 2 nanocomposites contain more oxygen defects, which is the primary factor enhancing the sensor's ability to detect gases. Firstly, indium ions are incorporated in the lattice of SnO 2 results in lattice distortion and enhances the presence of oxygen deficiency in the composites, which plays a pivotal role in achieving rapid response and recovery of the sensor. Secondly, In 2 O 3 -SnO 2 heterostructures promote rapid adsorption of oxygen molecules and target gases by facilitating effective electron mobility on their surface. The quicker response and recovery times of hydrogen sensors based on In 2 O 3 -SnO 2 heterojunctions are observed. This innovative approach to creating fast-responding gas sensors highlights the promise of heterojunction-based hydrogen sensors for real-time H 2 monitoring and opens up new research directions.
研究领域:
材料科学
·
传感器技术
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产品关联
DOI
高影响因子
TALANTA
·
2020
·
IF 5.339
Shuo Wu,Yan Zhao,Xunxun Deng,Xinlan Yang,Xiuyun Wang,Yanqiu Zhao
This work demonstrates that the photoelectrochemical response of the CdS/Bi 2 O 2.33 direct Z-scheme heterojunction, synthesized by in situ deposition of CdS nanocrystals on the defect engineered Bi 2 O 2.33 , can be modulated by oxygen defect concentration. The appropriate oxygen defects not only increase the visible light absorption, provide active reaction sites to enhance PEC activity, but also promote the separation of carriers. The formation of CdS/Bi 2 O 2.33 direct Z-scheme heterojunction further improves these properties by extending the visible light absorption and promoting separation and transport of carriers, but avoids the usage of noble metal nanoparticles as electron transfer mediators, thus has a low cost and easy fabrication technology. The CdS/Bi 2 O 2.33 direct Z-scheme junction shows significantly improved photocurrent response as compared with those containing less oxygen defects, and is applied as a photoelectrochemical assay platform for Hg 2+ . The specific interaction between Hg 2+ and the S 2− in CdS significantly quenches the photocurrent response of the CdS/Bi 2 O 2.33 due to the formation of HgS. The photocurrent decrease is linear to the concentration of Hg 2+ in the range from 10 −11 to 10 −6 g/mL, with the limit of detection of 3.2 pg/mL. High accuracy and good reproducibility are realized in the real sample analysis of urine, river water, and sea water. The integration of oxygen defect engineering and direct Z-scheme electron transport principle provides a new avenue for fabricating high performance photoelectrochemical materials, which can be further combined with bio-recognition strategy for the ultrasensitive detection of biological molecules.
研究领域:
材料科学
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环境科学
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Qingqing Liu,Chaofan Hu,Xiaomin Wang
Tungsten oxide has attracted considerable attention as a typical photochromic material. Herein, a simple route for the synthesis of tungsten oxide quantum dots (WO 3-x QDs) was demonstrated which was accomplished by the hydrothermal treatment of ammonium tungstate hydrate in the present of polyvinyl pyrrolidone (PVP). This photochromic material can rapidly undergo a color change reaction under the irradiation of ultraviolet or solar light. More importantly, the bleaching can be completed in a dark environment for 5 min and the cycle stability is excellent. The ultra-small size, existence of oxygen deficiency, and the surface modification by PVP are attribute to fast photochromic performance, excellent reversibility and cycling stability of WO 3-x QDs.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yang Song,Yifei Geng,Ziyu Peng,Qingjun Zhu,Siping Liang,Yuehua Li,Jing Zhu,Yongguang Liu,Lei Dai,Zhangxing He,Ling Wang
For its high specific discharge capacity and low working voltage, lithium vanadate is considered a promising anode material . However, inherent low conductivity and unsatisfactory cycle performance limit its further application. In this work, doping at the V site does not destroy the crystal structure of lithium vanadate but also increases the lattice volume. Moreover, the increased content of oxygen defect in the presence of redox reaction effectively improves the electrochemical properties of lithium vanadate. At the same time, the enhancement of hydrophilicity effectively improves the migration rate of ions. Among all LiLa x V 3-x O 8 samples, LiLa 0.01 V 2.99 O 8 (LVO-La-10) demonstrates better rate and cycle performance. LVO-La-10 delivers specific discharge capacities of 93.5 mAh g 1 at 0.5 C, and 42.8 mAh g −1 at 7 C, which is 17.4 and 16.7 mAh g −1 larger than that of lithium vanadate, respectively. Moreover, the capacity retention rate of LVO-La-10 (87.8%) is still higher than that of lithium vanadate (75.8%) at the rate of 0.2 C after 100 cycles. This work exhibits that increasing the lattice volume and oxygen defect of lithium vanadate effectively improves its electrochemical performance.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
Nature Communications
·
2025
·Vol. 16
·期 1
·1-12
·
IF 15.7
Wang Shijie,Liang Kang,Zhao Hongshun,Wu Min,He Junfeng,Wei Peng,Ding Zhengping,Li Jianbin,Huang Xiaobing,Ren Yurong
High-capacity power battery can be attained through the elevation of the cut-off voltage for LiNi 0.83 Co 0.12 Mn 0.05 O 2 high-nickel material. Nevertheless, unstable lattice oxygen would be released during the lithium deep extraction. To solve the above issues, the electronic structure is reconstructed by substituting Li + ions with Y 3+ ions. The dopant within the Li layer could transfer electrons to the adjacent lattice oxygen. Subsequently, the accumulated electrons in the oxygen site are transferred to nickel of highly valence state under the action of the reduction coupling mechanism. The modified strategy suppresses the generation of oxygen defects by regulating the local electronic structure, but more importantly, it reduces the concentration of highly reactive Ni 4+ species during the charging state, thus avoiding the evolution of an unexpected phase transition. Strengthening the coupling strength between the lithium layers and transition metal layers finally realizes the fast-charging performance improvement and the cycling stability enhancement under high voltage.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
·
2024
·
IF 4.3
Zhiqiang Wang,Xiaomei Zhou,Gehui Wang,Qing Tong,Haiqin Wan,Lin Dong
The elimination of toluene is an obligatory target with increasing VOC emission in recent years. This study successfully prepared a single-atom Ir catalyst (Ir1/CeO2) by a simple incipient wetness impregnation method, confirmed by in situ CO DRIFTS and AC-HAADF-STEM. Compared to the cluster Ir catalyst (Ir/CeO2-C), Ir1/CeO2 exhibited excellent catalytic performance, stability, and water resistance for the oxidation of toluene. By Raman, H2-TPR, O2-TPD, and XPS experiments, abundant oxygen defects and a unique Ir3+–Ov–Ce3+ structure were formed for the Ir1/CeO2 sample because it had a lower oxygen vacancy formation energy. Furthermore, the DFT results revealed that the Ir1/CeO2 sample had a lower ring-opening energy barrier and adsorption energy of the ring-opening products, which was the rate-determining step for the oxidation of toluene. This work provides instructive insights into the construction of Ir/CeO2 catalysts for the highly efficient removal of VOCs.
研究领域:
催化化学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）