Inorganic Chemistry Frontiers
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2021
·Vol. 8
·期 15
·3723-3732
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IF 6.569
Yuwei Zhang,Xiaoxiang Xu
Solid solutions of LaTaON2 and BaTaO2N, i.e., La1−xBaxTaO1+yN2−y (0 ≤ x, y ≤ 1), have been investigated as visible-light-active photocatalysts for water oxidation reactions. A number of important parameters such as Ta–O/N distance, Ta–O/N–Ta angle, band gap and band edge alignments can be tailored by adjusting their solid solution levels, which in turn, effectively steer the photocatalytic behaviors. In particular, optimal photocatalytic activity for water oxidation can be achieved in the solid solution La0.2Ba0.8TaO1+yN2−y (x = 0.8), exhibiting an apparent quantum efficiency (AQE) as high as 3.91% at 420 ± 20 nm. This work signifies the usefulness of the solid solution strategy for ameliorating the photocatalytic properties of perovskite oxynitrides that can be well-extended to many other semiconductor photocatalysts.
研究领域:
材料科学
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化学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 10
·5702-5711
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IF 10.733
Yawei Wang,Shu Jin,Guoxiang Pan,Zuxin Li,Long Chen,Gang Liu,Xiaoxiang Xu
In spite of strong visible light absorption and ideal band edge positions, LaTaON2 normally has very poor photocatalytic activity under ordinary conditions. Previous modifications of LaTaON2 such as aliovalent doping generally lead to strong reduction of its visible light absorption, being unfavorable for solar energy harvesting. Here, we introduce Zr into the structure of LaTaON2 (i.e. LaTa1−xZrxO1+yN2−y (0 ≤ x ≤ 0.15)) and successfully improve its photocatalytic activities without sacrificing its light absorption capability. More importantly, Zr doping helps to reduce Ta4+ defect concentration, improve surface hydrophilicity and induce mesoporous microstructures in LaTaON2, all of which contribute to the superior photocatalytic activities for water splitting reactions. Apparent quantum efficiency as high as 0.93% at 420 ± 20 nm has been achieved on LaTa0.9Zr0.1O1+yN2−y (x = 0.10) for photocatalytic water oxidation reactions, being the highest AQE reported for LaTaON2 to date. Further photoelectrochemical analysis suggests that Zr doped LaTaON2 has better charge separation conditions, smaller interfacial charge transfer resistance and longer electron lifetime compared to pristine LaTaON2. This simple method using Zr as a dopant can be well extended to other perovskite oxynitrides.
研究领域:
材料科学
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光催化
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能源化学
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无机功能材料
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半导体光化学
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DOI
高影响因子
JOURNAL OF CATALYSIS
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2020
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IF 7.888
Ran Wang,Yawei Wang,Shufang Chang,Shu Jin,Yinlin Shao,Xiaoxiang Xu
Complete solid solutions between LaTaON 2 and SrZrO 3 , i.e. (LaTaON 2 ) 1−x (SrZrO 3 ) x (0 ≤ x ≤ 1) have been built which are very useful in tailoring many important parameters of LaTaON 2 . Band gap of LaTaON 2 becomes tunable by controlling the level of solid solutions with SrZrO 3 . Structural distortions, defects (e.g. Ta 4+ species) concentration and surface hydrophilicity of LaTaON 2 are largely improved by introducing SrZrO 3 in the structure. These modifications contribute to much enhanced photocatalytic activities of solid solutions for oxygen production which clearly outperform pristine LaTaON 2 under visible light illumination. Apparent quantum efficiency as high as 0.87% at 420 ± 20 nm was achieved at (LaTaON 2 ) 0.6 (SrZrO 3 ) 0.4 (x = 0.4). Further analysis suggest that introducing SrZrO 3 results in realignment of band edge positions of LaTaON 2 so as to be more appropriate for water splitting reactions.
研究领域:
材料科学
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光催化化学
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产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
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2023
·
IF 10.9
Guoan Lin,Chi Zhang,Xiaoxiang Xu
Charge separation is generally considered as the most critical step to achieve efficient photocatalytic reactions. Although charge separation can be promoted by a semiconductor heterojunction, its efficacy is inherently restrained by the mismatched atomic arrangements across the heterojunction interfaces. Here, Ta 3 N 5 –LaTaON 2 heterojunction with matched interfaces has been fabricated by one-step ammonolysis treatment of KLaTa 2 O 7 . The match interfaces are formed by nearly perfect adhesion of Ta 3 N 5 (010) and LaTaON 2 (10 1 ¯ ) facets whose interatomic distance is similar. Compared with conventional heterojunction, the so-formed Ta 3 N 5 –LaTaON 2 heterojunction are extremely efficient in accelerating charge separation which in turn enables a high photocatalytic activity. An apparent quantum efficiency as high as 11.6% at 420 ± 20 nm has been reached by Ta 3 N 5 –LaTaON 2 heterojunction, which is almost three times higher than Ta 3 N 5 /LaTaON 2 mixtures. These results signify the importance of matched heterojunction interfaces for charge separation and provide a paradigm in the design of efficient heterojunction-based semiconductor photocatalysts.
研究领域:
材料科学
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能源化学
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产品关联
DOI
高影响因子
ACS Nano
·
2021
·
IF 15.881
Shufang Chang,Jinxing Yu,Ran Wang,Qingyang Fu,Xiaoxiang Xu
LaTaON2 porous single crystals (PSCs), integrating structural coherence and porous microstructures, will warrant promising photocatalytic performance. The absence of grain boundaries in PSCs ensures rapid photocarrier transportation from bulk to the surface, thereby mitigating photocarriers’ recombination. Porous microstructures not only provide ample reachable surface to host photochemical reactions but also reinforce photon-matter interactions by additional photon reflection/scattering. Here, we have synthesized LaTaON2 PSCs via a topotactic route and show significantly improved photocatalytic performance. Efficient water oxidation into O2 has been realized by LaTaON2 PSCs with an apparent quantum efficiency as high as 5.7% at 420 ± 20 nm. Stable overall water splitting into stoichiometric H2 and O2 has also been achieved in a Z-scheme setup using LaTaON2 PSCs as the O2 evolution photocatalyst. These results not only prove that PSCs facilitate photocarrier migrations, which in turn deliver exceptional photocatalytic performance, but also imply that PSCs are useful to reinvigorate conventional semiconductor photocatalysts toward efficient solar energy conversions.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2014
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IF 2.93
Li Zhang,Yan Song,Jianyong Feng,Tao Fang,Yujiao Zhong,Zhaosheng Li,Zhigang Zou
Lanthanum tantalum oxynitride (LaTaON 2 ) powders were prepared by one-step flux method. LaTaON 2 photoanodes, which are fabricated by using LaTaON 2 powders, are found to exhibit photoelectrochemical activity for overall water splitting . The photocurrent for LaTaON 2 photoelectrodes was ca. 120 μA cm −2 at 1.5 V vs. reversible hydrogen electrode (RHE) in 1 M NaOH aqueous solutions (pH = 13.6) under AM 1.5 G simulated sunlight irradiation (100 mW cm −2 ). The photocurrent of LaTaON 2 photoelectrode from back-side illumination is much larger than that from front-side illumination, suggesting that the photoelectrochemical property is mainly limited by poor continuous electron transport in the bulk. Further efforts to ameliorate the electron transport in the bulk of LaTaON 2 photoelectrodes are expected to significantly improve their photoelectrochemical performance.
研究领域:
材料科学
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能源科学
✓ 已验证
DOI
高影响因子
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