The Innovation
·
2022
·Vol. 3
·期 4
·100268-100268
·
IF 0
Zichuang Li,Ruguang Ma,Qiangjian Ju,Qian Liu,Lijia Liu,Yufang Zhu,Minghui Yang,Jiacheng Wang
Single-site metal atoms (SMAs) on supports are attracting extensive interest as new catalytic systems because of maximized atom utilization and superior performance. However, rational design of configuration-optimized SMAs with high activity from the perspectives of fundamental electron spin is highly challenging. Herein, N-coordinated Fe single atoms are successfully distributed over axial carbon micropores to form dangling-FeN 4 centers (d-FeN 4 ). This unique d-FeN 4 demonstrates much higher intrinsic activity toward oxygen reduction reaction (ORR) in HClO 4 than FeN 4 without micropore underneath and commercial Pt/C. Both theoretical calculation and electronic structure characterization imply that d-FeN 4 endows central Fe with medium spin (t 2g 4 e g 1 ), which provides a spin channel for electron transition compared with FeN 4 with low spin. This leads to the facile formation of the singlet state of oxygen-containing species from triplet oxygen during the ORR, thus showing faster kinetics than FeN 4 . This work provides an in-depth understanding of spin tuning on SMAs for advanced energy catalysis.
研究领域:
催化化学
·
材料科学
·
理论计算
✓ 已验证
DOI
PubMed
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Miaoli Gu,Yi Yang,Liuyang Zhang,Bicheng Zhu,Guijie Liang,Jiaguo Yu
Solar H 2 O 2 generated from O 2 and H 2 O is an economical and green protocol. However, most photocatalysts only perform well in the presence of sacrificial donors or the photocatalysts are composed by organic materials, thus hindering their applicability. Herein, an inorganic matrix, i.e. ZnIn 2 S 4 @BiVO 4 (ZIS@BVO), is constructed as a model catalyst for photocatalytic H 2 O 2 production in non-sacrificial systems. Excellent performance (1.8 mmol g −1 h −1 ) under visible-light is realized, and an apparent quantum yield of 5.18% is realized at 420 nm. Thorough investigation helps us to rationalize its exceptional performance and structural characteristics. Of note, the electron spin resonance spectroscopy results, in combination with scavenger capture experiments, reveal the discovery of an overlooked pathway. Specifically, except for the well-known two-electron oxygen reduction reaction (ORR), the involvement of 1 O 2 intermediate is verified during the H 2 O 2 generation. Beyond presenting high performance of the inorganic composites, this finding also discloses a different reaction path for H 2 O 2 production.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of the American Chemical Society
·
2024
·
IF 14.4
Liu Lin,Yunming Xu,Yiting Han,Ruikun Xu,Tongyue Wang,Zemin Sun,Zhenhua Yan
A deep understanding of the mechanism for the spin-magnetic effect on O–H cleavage is crucial for the development of new catalysts for water oxidation. Herein, we designed and synthesized the crystalline Fe-DABDT and Co-DABDT (DABDT = 2,5-diaminobenzene-1,4-dithiol) and optimized an effective magnetic moment to explore the role of the spin-magnetic effect in the regulation of water oxidation activity. It can be found that the OER activity of the catalyst is positively correlated with its effective magnetic moment. Under the external magnetic field, Fe-DABDT with more spin single electrons has a stronger spin-magnetic response to water oxidation than Fe/Co-DABDT and Co-DABDT. The increase in OER current of Fe-DABDT is nearly 2 times higher than that of Co-DABDT. Experimental and density functional theory studies show that magnetized Fe sites could realize nucleophilic reaction, accelerate the polarization of electron spin states, and promote the polar decomposition of O–H and the formation of the O–O bond. This study provides mechanistic insight into the spin-magnetic effect of oxygen evolution reaction and further understanding of the spin origin of catalytic activity, which is expected to improve the energy efficiency of hydrogen production.
研究领域:
化学
·
材料科学
·
催化反应
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-9
·
IF 12.121
Pan Lun,Ai Minhua,Huang Chenyu,Yin Li,Liu Xiang,Zhang Rongrong,Wang Songbo,Jiang Zheng,Zhang Xiangwen,Zou Ji-Jun,Mi Wenbo
Photocatalysis has been regarded as a promising strategy for hydrogen production and high-value-added chemicals synthesis, in which the activity of photocatalyst depends significantly on their electronic structures, however the effect of electron spin polarization has been rarely considered. Here we report a controllable method to manipulate its electron spin polarization by tuning the concentration of Ti vacancies. The characterizations confirm the emergence of spatial spin polarization among Ti-defected TiO 2 , which promotes the efficiency of charge separation and surface reaction via the parallel alignment of electron spin orientation. Specifically, Ti 0.936 O 2 , possessing intensive spin polarization, performs 20-fold increased photocatalytic hydrogen evolution and 8-fold increased phenol photodegradation rates, compared with stoichiometric TiO 2 . Notably, we further observed the positive effect of external magnetic fields on photocatalytic activity of spin-polarized TiO 2 , attributed to the enhanced electron-spin parallel alignment. This work may create the opportunity for tailoring the spin-dependent electronic structures in metal oxides.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 6
·3298-3310
·
IF 3.591
Zhi-Yu Liang,Ren-Kun Huang,Ruo-Wen Liang,Dan-Hua Xie,Gui-Yang Yan
Nowadays, visible-light-driven photocatalysts are considered to be prospective candidates for solving the crisis of energy shortage and environment pollution. Herein, with the support of WO3 nanorods (NRs), which possess a fast electron transmission and low carrier diffusion, a series of direct Z-scheme ZnIn2S4/WO3 photocatalysts are exquisitely fabricated by an in situ self-assembly route with ZnIn2S4 (ZIS) and WO3 NRs. Photocatalytic activities towards both selective hydrogenation of aromatic nitro compounds and non-selective oxidation of organic compounds demonstrate that these as-fabricated heterostructured nanocomposites exhibit remarkably enhanced photocatalytic activities owing to the highly efficient separation of photogenerated electrons and holes. Furthermore, the characteristics of electron spin resonance (ESR) spectra clearly suggest that the as-fabricated nanocomposites follow the direct Z-scheme-dominated photoredox catalytic mechanism. Additionally, combining the results of ESR and X-ray photoelectron spectroscopy (XPS), it can be concluded that the photo corrosion of ZnIn2S4 is significantly postponed after integration with WO3 NRs. Finally, we will be greatly pleased if this work could afford a theoretical exemplification and synthetic strategy for rationally designing and utilizing direct Z-scheme photocatalysts.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
RADIATION PHYSICS AND CHEMISTRY
·
2022
·
IF 2.776
Zhenyan Ji,Fan Zhang,Hongbing Chen,Rongfang Shen,Weirong He,Zhe Xing,Guozhong Wu
Epoxy resins are radiation-resistant polymers that are widely employed in aerospace and nuclear facilities; however, free radicals formed by ionizing radiation may lead to changes in their physicochemical properties. In this study, bisphenol-A based epoxy resin samples in both air and vacuum environments were subjected to gamma irradiation with doses up to 1000 kGy and the generated free radicals were investigated by electron spin resonance (ESR). Four radicals, namely cyclohexadienyl-type radicals, phenoxy radicals, peroxy radicals, and alkyl radicals, were formed in epoxy resin in both environments after gamma irradiation. The ESR spectra showed that the free radicals yield produced in the air was significantly larger than that produced in a vacuum. The radical concentration of the EP increased until a dose of 500 kGy and approached saturation upon increasing the dose to 1000 kGy. The ESR spectra of the EP annealed between 50 and 160 °C indicated that the radical concentration decreased with increasing temperature. The radicals in the EP samples irradiated in air disappeared at an annealing temperature of 130 °C, close to the glass transition temperature of the EP. The radicals in the EP irradiated in vacuum still remained even at 160 °C, which can be attributed to the stable phenoxy radicals. The free radical reaction mechanism was also developed for the bisphenol-A based EP irradiated by gamma-ray in different atmospheres.
研究领域:
材料科学
·
辐射生物学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2020
·
IF 6.215
Yi Zhang,Xiaobin Gao,Lin Lv,Jie Xu,Haofeng Lin,Yigang Ding,Chundong Wang
Developing highly efficient and affordable catalysts towards oxygen evolution reaction (OER) is highly desirable, but still faces challenges. Here, we report a novel Fe doped CoP nanocuboid (Co x Fe 1-x P) via the successive oxidation and phosphidation of the Co–Fe precursor strategy. By preparation and measurement of the control samples, the optimized Co 0.8 Fe 0.2 P is found, affording an overpotential of 285 mV to deliver a current density of 10 mA cm −2 , yielding a Tafel slope of 40 mV dec −1 , and endowing robust stability for 10 h with only 5.78% degradation. The outstanding OER performance should be ascribed to the redistribution of the electron spin status via π-donation due to the introduction of Fe into the CoP lattices, enabling optimization of the adsorption/desorption feature of the intermediate species on the catalyst surface. This work paves the ways for exploration of high efficient catalysts with deliberate electron spin tailoring.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
FOOD RESEARCH INTERNATIONAL
·
2022
·
IF 7.425
Jianmei Yang,Likang Qin,Yong Zhu,Chongyun He
In this study, the radicals formed in camellia oil upon a heating process were identified and quantified using Electron Spin Resonance (ESR) spectroscopy coupled with spin-trapping technique. PBN and DMPO were served as spin traps. The total amounts of free radicals of heated camellia oil showed an increasing trend with the extension of heating time at 140 °C, 150 °C and 160 °C. In accordance with hyperfine splitting constants (aN, aH) ─ the crucial parameter for identifying free radical species ─ of free radical, it was definitely confirmed that alkyl, alkoxyl, oxygen-centered and DMPO oxidate free radicals were present in heated camellia oil. A free radical transition pathway was proposed that alkyl free radical is initially generated, then, alkyl peroxy free radical is subsequently generated in the presence of oxygen which eventually shifts into alkoxyl free radical by means of an intermediate formed from H-capture reaction of alkyl peroxy free radical.
研究领域:
食品科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Science Bulletin
·
2023
·
IF 18.9
Canhui Zhang,Xingkun Wang,Zhentao Ma,Hanxu Yao,Hengjun Liu,Cheng Li,Jian Zhou,Ren Xu,Xusheng Zheng,Huanlei Wang,Qiang Li,Meng Gu,Heqing Jiang,Minghua Huang
Breakthrough in developing cost-effective Fe-based catalysts with superior oxygen reduction reaction (ORR) activities and ultra-long-term stability for application in Zn-air batteries (ZABs) remain a priority but still full of challenges. Herein, the neighboring NiN 4 single-metal-atom and Fe 2 N 5 dual-metal-atoms on the N-doped hollow carbon sphere (Fe/Ni-NHCS) were deliberately constructed as the efficient and robust ORR catalyst for ZABs . Both theory calculations and magnetic measurements demonstrate that the introduction of NiN 4 provides a significant role on optimizing the electron spin state of Fe 2 N 5 sites and reducing the energy barrier for the adsorption and conversion of the oxygen-containing intermediates, enabling the Fe/Ni-NHCS with excellent ORR performance and ultralow byproduct HO 2 − yield (0.5%). Impressively, the ZABs driven by Fe/Ni-NHCS exhibit unprecedented long-term rechargeable stability over 1200 h. This work paves a new venue to manipulate the spin state of active sites for simultaneously achieving superior catalytic activities and ultra-long-term stability in energy conversion technologies.
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nano Energy
·
2024
·
IF 16.8
Zuming He,Kai Lin,Ngie Hing Wong,Jaka Sunarso,Yongmei Xia,Xiaofei Fu,Bin Tang,Zhengyi Huang,Yong Wang,Hanpei Yang
The pyroelectric effect and electron spin-state reconfiguration play a critical role in photocatalysis but are seldom investigated. This work is the first to exploit the fluctuating temperature (Δ T ) between the cold-hot alternation in photocatalysis to drive the pyroelectric effect and electron spin-sate reconfiguration. FeS 2 /CuCo 2 O 4 (FS/CCO) hollow core-shell heterojunctions were prepared using hydrothermal and heating treatment methods. The FeS 2 (FS) can generate heat under near-infrared (NIR) light to provide the elevated temperature end required for the pyroelectric effect of CuCo 2 O 4 (CCO) under the influence of Δ T . With this thermoelectric and pyroelectric effect, CCO can release surface charges, generating spontaneous polarization, changing the electron (e g ) filling number on Co surface sites, reversing the spin electron state, thus controlling the carriers' migration direction and enhancing their separation and migration rate, and finally prolonging their lifetime. As a result, the as-designed FS/CCO-15 composites yielded up to 19.5 mmol g −1 h −1 extraordinary photocatalytic performance, i.e., 10.2 and 6.45-fold of the pure FS (1.92 mmol g −1 h −1 ) and CCO (3.02 mmol g −1 h −1 ) under simulated sunlight, respectively. It also yielded up to 19.8% average apparent quantum yield. This work thoroughly explored the distinctive impact of the pyroelectric effect, electron spin-state reconfiguration, orbital coupling effect, and hydrogen evolution, guiding us and creating more possibilities for photocatalytic technology and efficiency using NIR light.
研究领域:
材料科学
·
光催化技术
·
能源转换与存储
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2022
·
IF 10.383
Hang-bo Zheng,Yuan-li Wang,Jia-wei Xie,Peng-zhao Gao,Dong-yun Li,Evgeny V Rebrov,Hang Qin,Xiao-pan Liu,Han-ning Xiao
Renewable electricity from splitting water to produce hydrogen is a favorable technology to achieve carbon neutrality, but slow anodic oxygen evolution reaction (OER) kinetics limits its large-scale commercialization. Electron spin polarization and increasing the reaction temperature are considered as potential ways to promote alkaline OER. Here, it is reported that in the alkaline OER process under an AC magnetic field, a ferromagnetic ordered electrocatalyst can simultaneously act as a heater and a spin polarizer to achieve significant OER enhancement at a low current density. Moreover, its effect obviously precedes antiferromagnetic, ferrimagnetic, and diamagnetic electrocatalysts. In particular, the noncorrected overpotential of the ferromagnetic electrocatalyst Co at 10 mA cm–2 is reduced by a maximum of 36.6% to 243 mV at 4.320 mT. It is found that the magnetic heating effect is immediate, and more importantly, it is localized and hardly affects the temperature of the entire electrolytic cell. In addition, the spin pinning effect established on the ferromagnetic/paramagnetic interface generated during the reconstruction of the ferromagnetic electrocatalyst expands the ferromagnetic order of the paramagnetic layer. Also, the introduction of an external magnetic field further increases the orderly arrangement of spins, thereby promoting OER. This work provides a reference for the design of high-performance OER electrocatalysts under a magnetic field.
研究领域:
能源材料科学
·
电化学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2013
·Vol. 15
·期 44
·19422-19426
·
IF 3.829
Weiming Wu,Rui Lin,Lijuan Shen,Ruowen Liang,Rusheng Yuan,Ling Wu
CdS photocatalysts with tunable band gaps (2.17–2.32 eV) were successfully prepared by a solvothermal method. Photocatalytic hydrogenation of 4-nitroaniline over the obtained samples was evaluated in the presence of HCO2NH4 as a hole scavenger upon purging with N2 under visible light irradiation (λ ≥ 420 nm). The CdS sample prepared by CdCl2 and sulfur powder in ethylenediamine showed excellent catalytic activity, giving 100% of 4-nitroaniline conversion and 95% of p-phenylenediamine selectivity after 35 min of visible light irradiation. The results of electron spin resonance revealed that its photoexcited holes could efficiently react with HCO2− ions within HCO2NH4 molecules to produce ˙CO2− radicals with strong reductive abilities. Furthermore, photoexcited electrons of the obtained sample exhibited relatively strong reductive abilities as compared to other CdS samples. Therefore, this sample showed the highest catalytic activity among the CdS samples for the photocatalytic hydrogenation of 4-nitroaniline.
研究领域:
材料科学
·
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）