APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Hongjun Fang,Yusong Pan,Haixian Yan,Xiulong Qin,Chao Wang,Linfeng Xu,Chengling Pan
A novel Yb 3+ /Tm 3+ co-doped Ti 3 C 2 /Ag/Ag 3 VO 4 composite with stable and robust photodegradation performance was synthesized by in-situ partially reduction along with hydrothermal strategy. In the composite, block-like Ag 3 VO 4 particles are self-assembled on the surface of 2D Ti 3 C 2 MXene accompanied by partial reduction of Ag + to Ag 0 . Photodegradation results showed that the resulting Yb 3+ /Tm 3+ co-doped Ti 3 C 2 /Ag/Ag 3 VO 4 composite with optimal Yb/Tm proportion (Y/T:0.3/0.005) presented a boosting photocatalytic performance for degradation of tetracycline (TC) and organic dyes under visible light irradiation. The removal efficiency was 97% for TC in 20 min, 96% for rhodamine B in 25 min, and 99% for methylene blue in 20 min, which was higher than that of Ag/Ag 3 VO 4 composite. As manifested by photoelectrochemical measurements, the enhanced photocatalytic performance of the Y/T:0.3/0.005 composite was attributed to the improved light absorption and excellent charge separation induced by the formation of intermediate energy states after co-doping Yb 3+ /Tm 3+ ions. Meanwhile, the photocatalytic mechanism of the photocatalyst was also investigated through electron spin resonance (ESR) spectra and trapping experiments, which verified that the active species of h + and ·O 2 − play the important role for photodegradation of tetracyline and organic dyes.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 112
·111052-111059
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IF 3.289
Yuemei Li,Rui Wang,Yanling Xu,Jianjun Zhou,Zhihua Liu,Xiaojing Yan,Li Ma
ZnO:Yb3+,Tm3+,Ga3+ up-conversion nanoparticles (UCNPs) with sizes of between 20 and 65 nm are synthesized by the hydrothermal method. The size of the nanocrystals is affected by different Ga3+ concentrations. The variation in size has influence on the particles' visible blue and red up-conversion (UC) emission. In this paper, X-ray powder diffraction results show different amounts of gallium substituting for Zn in the ZnO lattice. When the concentration of Ga3+ is 3 mol%, the resulting UCNPs exhibit strong UC emission, longer fluorescence lifetime and narrower band gap. Due to their adjustable size and UC fluorescence properties, ZnO:Yb3+,Tm3+,Ga3+ nanocrystals have broad prospects for future applications in the biomedical field.
研究领域:
材料科学
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纳米医学
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生物光子学
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无机功能材料
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分子影像
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
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2014
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IF 1.716
J. Yuan,W.C. Wang,D.D. Chen,M.Y. Peng,Q.Y. Zhang,Z.H. Jiang
Enhanced 1.8 μm emission from Tm 3+ by Yb 3+ sensitization and bubbling in tungsten tellurite glasses has been demonstrated under the excitation of a 976 nm laser diode . Radiative properties such as spontaneous emission probabilities, radiative lifetimes and fluorescence branching ratios along with absorption and emission cross sections have been calculated from the absorption spectra . The influences of Yb 3+ concentration, Tm 3+ concentration, and bubbling time on spectroscopic properties have been thoroughly investigated. It is found that with increasing the bubbling time to 35 min, OH − content deceases sharply while 1.8 μm emission intensity improves greatly and 3 F 4 level lifetime prolongs to 1.57 ms close to radiative time. After 35 min, they change very little due to almost reaching the dynamic balance. The strength of interaction between Tm 3+ and OH − is determined. The energy transfer mechanism between Yb 3+ and Tm 3+ is proposed by photoemission spectroscopy and lifetime measurement. The energy transfer coefficients have been analyzed by the extended spectral overlap method and hopping model. Large ratio of the forward energy transfer from Yb 3+ to Tm 3+ to the backward one (223) and high energy transfer efficiency (97%) from Yb 3+ to Tm 3+ ensure efficient 1.8 μm emission. Hence, Yb 3+ sensitization and the reduction of OH − content could be expected to open up a possibility to achieve high efficient 2.0 μm lasing from Tm 3+ under a 976 nm LD pump.
研究领域:
光学材料
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激光物理
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固体激光器
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光谱学
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无机非金属材料
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光子学
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稀土发光材料
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2020
·Vol. 49
·期 40
·14030-14045
·
IF 4.174
Kailian Zhang,Jie Guan,Ping Mu,Kai Yang,Yu Xie,Xiaoxiao Li,Laixi Zou,Weiya Huang,Changlin Yu,Wenxin Dai
To effectively enhance the utilization of clean sunlight energy, harvesting a large percentage of near infrared (NIR) light is significant. One of the commonly used effective methods for modifying semiconductors is by co-doping upconversion materials on semiconductors to heighten the photocatalytic efficiency. In this work, Yb3+/Tm3+ co-doped InVO4 nanosheets were synthesized by a facile hydrothermal path, and the crystal phases, morphologies, surface chemical compositions, as well as optical properties were characterized. Yb3+/Tm3+ co-doped InVO4 revealed significantly enhanced photoactivity towards chromium(VI) reduction and methyl orange oxidation under visible or NIR light irradiation. Furthermore, 5YT-IV presented the highest electrocatalytic performance and photocatalytic production of H2O2 under visible light irradiation, requiring low overpotential and low Tafel slope (390 mV dec−1) for hydrogen evolution reaction than that of the bare InVO4 (731 mV dec−1), and as well improved the yield of photocatalytic H2O2 production by about 3.5 times. This was primarily ascribed to intensive light absorption resulting from the benign upconversion energy transfer of Yb3+/Tm3+ and the boosted charge separation caused by the intermediate energy states. Moreover, the presence of h+ and ˙O2− as the main oxidative species played a significant role during the photocatalytic oxidation process of methyl orange and electrons played a decisive role in Cr(VI) reduction. This study provides a promising platform for efficiently utilizing the visible-NIR energy of sunlight in the field of photocatalytic H2O2 production and for alleviating environmental pollution in future.
研究领域:
材料科学
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光催化
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环境科学
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能源转换
✓ 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）