JOURNAL OF ALLOYS AND COMPOUNDS
·
2016
·
IF 3.014
Yitao Wu,Yinyan Gong,Jiaqi Liu,Zhen Zhang,Yan Xu,Hui Ren,Can Li,Lengyuan Niu
B and Y doped titanium dioxides (TiO 2 ) photocatalysts were synthesized by a sol-gel method followed by calcination . It is observed that the photodegradation efficiency of B and Y co-doped TiO 2 is twice that of undoped sample. To explore the underlining mechanism, x-ray diffraction, Raman, scanning electron microscope, x-ray photoemission, and UV–Vis diffuse reflectance spectroscopy measurements have been carried out to investigate the effect of B and Y doping on the structural, electronic, and optical properties of titania. Experimental observations revealed that in TiO 2 lattice Y 3+ ions tend to replace Ti 4+ ions while B 3+ ions occupy the interstitial sites. The incorporation of interstitial boron dopants will create oxygen vacancies ( Ov ·· ) and reduce Ti 4+ to Ti 3+ to form [ Ov ·· -Ti 3+ ] + complex, which traps the carriers and prolongs carrier lifetime. Moreover, Y 3+ ions can trap the photo-excited electrons to form Y 2+ ions, which will then react with the absorbed O 2 on TiO 2 surface to generate reactive species. In addition, all the doped samples have smaller crystallite sizes . The formation of B interstitials and Y substitutes, and increased surface-to-volume ratio are all beneficial to improve photocatalytic activity.
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
ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Kang Lei,Haiming Huang,Xu Jia Liu,Weiliang Wang,Kai Guo,Ren Kui Zheng,Han Li
The eco-friendly thermoelectric material SnTe has recently gained immense attention due to its excellent thermoelectric properties and potential. However, its thermoelectric properties are limited by the inherent high carrier concentration (low Seebeck coefficient) and high thermal conductivity. Herein, we further introduce rare-earth element Y on top of the conventional Cu alloying to more effectively modulate its microstructure and thermal transport properties. The experimental results reveal that Y doping gives rise to band convergence, endowing Sn1–xYxTe-5%Cu2Te with an increased power factor of ∼22.14 μW cm–1 K–2. Meanwhile, the introduced abundant Y/Y2Te3 multiscale composite nanostructures in the matrix greatly enhance phonon scattering, resulting in an ultra-low lattice thermal conductivity of ∼0.43 W m–1 K–1. Consequently, these combined effects resulted in a peak ZT value of 1.27 at 823 K in Sn0.97Y0.03Te-5%Cu2Te. An enhancement of nearly 217% is achieved compared to pristine SnTe, which greatly improves the thermoelectric properties of SnTe-based materials.
研究领域:
材料科学
·
热电材料
✓ 已验证
产品关联
DOI
高影响因子
Asia-Pacific Journal of Chemical Engineering
·
2022
·Vol. 18
·期 2
·e2863
·
IF 1.777
Jingyi Wang,Lili Cai,Zhongwei Cao,Xuefeng Zhu,Weishen Yang
Oxidative coupling of methane (OCM) is an effective route for methane direct conversion to ethylene. Perovskite oxides (ABO 3 ) with variable properties are potential catalysts for OCM by adjusting the compositions. In this study, four perovskite catalysts, BaMO 3-δ and BaM 1-x Y x O 3-δ (M = Zr, Ce; x = 0.2), were prepared by the sol–gel method to explore their catalytic performance of OCM. All catalysts are active toward OCM and reach the highest catalytic performance at 800°C. The OCM performance of Ce-based catalysts is higher than that of Zr-based catalysts. The selectivity of C 2 compounds is significantly improved by Y-doping. At CH 4 /O 2 mol ratio of 8, a C 2 selectivity of 67% was achieved on BaCe 0.8 Y 0.2 O 3-δ . Compared with Zr-based catalysts, more amounts of active oxygen species, which are beneficial to OCM, were observed on BaCeO 3-δ and BaCe 0.8 Y 0.2 O 3-δ . Meanwhile, higher contents of moderate and strong basic sites, which are beneficial to OCM, were found on the Y-doped catalysts. This is attributed to the generation of oxygen vacancies caused by Y-doping in the B-site. Therefore, BaCe 0.8 Y 0.2 O 3-δ with more active oxygen species and stronger basicity exhibits the highest performance among the four catalysts.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2020
·Vol. 132
·期 1
·417-429
·
IF 1.52
Xie Qi,Miao Changxi,Lei Tianqi,Hua Weiming,Yue Yinghong,Gao Zi
Dehydrogenation of ethane assisted by CO 2 has been investigated over Au catalyst supported on Y-doped CeO 2 nanorod. The catalysts were characterized by XRD, TEM, N 2 adsorption, XPS, TG, H 2 -TPR and Raman spectroscopy. Enhanced activity can be obtained after the proper Y doping. The optimal catalyst Au/Ce 0.9 Y 0.1 exhibits an ethane conversion of 20.9% and nearly 100% selectivity to ethylene without any evident tendency of deactivation in 50 h. The reducibility of surface oxygen species is found to play a key role in the dehydrogenation assisted by CO 2 , which can be improved by proper Y doping into CeO 2 nanorod. The promoting effect of CO 2 on activity is evident over Au/Ce 0.9 Y 0.1 catalyst, due to the quick transformation of H 2 product into H 2 O by the reverse water gas shift reaction. The catalyst stability is also improved by the addition of CO 2 , attributed to the elimination of coke by Bouduoard reaction.
研究领域:
化学工程
·
催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2024
·
IF 15.8
Lu Yu,Xiao-Lei Shi,Yuanqing Mao,Wei-Di Liu,Zhen Ji,Sitong Wei,Zipei Zhang,Weiyu Song,Shuqi Zheng,Zhi-Gang Chen
Incorporating donor doping into Mg3Sb1.5Bi0.5 to achieve n-type conductivity is one of the crucial strategies for performance enhancement. In pursuit of higher thermoelectric performance, we herein report co-doping with Te and Y to optimize the thermoelectric properties of Mg3Sb1.5Bi0.5, achieving a peak ZT exceeding 1.7 at 703 K in Y0.01Mg3.19Sb1.5Bi0.47Te0.03. Guided by first-principles calculations for compositional design, we find that Te-doping shifts the Fermi level into the conduction band, resulting in n-type semiconductor behavior, while Y-doping further shifts the Fermi level into the conduction band and reduces the bandgap, leading to enhanced thermoelectric performance with a power factor as high as >20 μW cm–1 K–2. Additionally, through detailed micro/nanostructure characterizations, we discover that Te and Y co-doping induces dense crystal and lattice defects, including local lattice distortions and strains caused by point defects, and densely distributed grain boundaries between nanocrystalline domains. These defects efficiently scatter phonons of various wavelengths, resulting in a low thermal conductivity of 0.83 W m–1 K–1 and ultimately achieving a high ZT. Furthermore, the dense lattice defects induced by co-doping can further strengthen the mechanical performance, which is crucial for its service in devices. This work provides guidance for the composition and structure design of thermoelectric materials.
研究领域:
材料科学
·
物理学
·
纳米技术
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Mingzhe Li,Jiahui Zheng,Fengchun Zheng,Xin Zhang,Yunlong Wang,Kepi Chen,Nian Ran,Wei Zhou,Yuzhen Lv
Developing highly efficient catalysts with ultralow-loading metal is still hindered by the sluggish Volmer–Tafel kinetics for the alkaline hydrogen evolution reaction (HER). Herein, an efficient catalyst was designed and constructed on nickel foam by integrating oxyphilic Y-doped NiO with NiPt1% nanocrystalline via a facile one-step electrodeposition. It requires only 21.2 and 178.5 mV to achieve 10 and 1000 mA cm–2, with a low Tafel slope of 27.8 mV dec–1. Furthermore, it provides an ultrahigh mass activity of 42.7 mA μgpt–1 @ 100 mV and a high stability over 2000 h at 1 A cm–2 almost without potential decay. In-situ experiments and D2O electrolysis tests reveal that the oxyphilic Y-NiO component not only reduces the activation energy of NiPt1% alloy by 32% and enhances its surface hydrogen (*H) coverage 7.8 times but also markedly boosts the Volmer step. Density functional theory calculations further reveal that Y-NiO strengthens water adsorption and shifts both Volmer and Tafel steps on the NiPt1% alloy surface from nonspontaneous to spontaneous, while reducing their energy barriers by 32 and 23%, respectively. This work presents an effective approach for regulating the Volmer–Tafel process in ultralow-loading metal alloys for alkaline HER.
研究领域:
电化学
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催化
·
材料科学
·
能量转换
·
纳米技术
✓ 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）