Catalysis Science & Technology
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2017
·Vol. 7
·期 20
·4640-4647
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IF 5.773
Fangfang Wu,Xiaoqin Sun,Gang Liu,Xiaoxiang Xu
Despite a strong visible light absorption at a wavelength as far as 610 nm, SrTaO2N generally exhibits poor photocatalytic activity due to photocatalytic self-decomposition. In this study, we introduce Na into the B site of SrTaO2N and perform an investigation on its crystal structure, optical absorption and photocatalytic water oxidation in response to Na incorporation. Our results suggest that Na incorporation effectively enhances local Ta–O(N) bond strength, which is responsible for strong interband light absorption, low tendency to defect formation and high stability against photocatalytic self-decomposition. Efficient photocatalytic water oxidation was realized in Na-modified SrTaO2N (Sr0.8Na0.2TaO2.8N0.2) with an apparent quantum efficiency as high as 0.2% under visible light illumination (≥400 nm). This simple strategy highlights the benefits of alkaline metal modification and can be extended to other nitrides or oxynitrides where management of local bond strength is needed.
研究领域:
材料科学
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光化学
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能源转化
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表面化学
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无机化学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2021
·
IF 19.503
Lin Yang,Qingyang Fu,Lina Wang,Jinxing Yu,Xiaoxiang Xu
Porous single-crystalline SrTaO 2 N, combining structural homogeneity and high porosity, afford a great promise as an active photocatalyst. The lack of grain boundaries in SrTaO 2 N porous single crystals (PSCs) enables fast photocarrier migration from bulk to the surface whilst the high porosity offers adequate accessible surface to perform photocatalytic reactions. In this work, we demonstrate a facile synthesis of SrTaO 2 N PSCs via a topotactic conversion route. These SrTaO 2 N PSCs deliver exceptional activity and stability for photocatalytic O 2 production from water with a record-breaking apparent quantum efficiency as high as 17.9% at 420 ± 20 nm. Overall water splitting with H 2 /O 2 equals 2 has also been attained in a Z-scheme system employing SrTaO 2 N PSCs as the O 2 -evolution moiety. These results signify a paradigm to improve photocatalytic performance based on PSCs, which extends the toolbox to achieve efficient solar water splitting over conventional photocatalysts.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2018
·Vol. 6
·期 42
·20760-20768
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IF 9.931
Xiaoqin Sun,Fangfang Wu,Gang Liu,Xiaoxiang Xu
The perovskite oxynitride SrTaO2N is a promising compound for solar energy conversion because it has strong visible light absorption at wavelengths as long as 650 nm. However, its photocatalytic activity is generally very poor, primarily because of the high defect concentration induced during its synthetic procedures as well as photocatalytic self-decomposition events. In this work, we introduce Sr into the B site of SrTaO2N to form a complex perovskite oxynitride, Sr3(Sr1/3Ta2/3)3O9−xNy (i.e. Sr4Ta2O9−xNy). The new compound has a much lower defect concentration compared to SrTaO2N and much higher stability against photocatalytic self-decomposition. More importantly, Sr4Ta2O9−xNy demonstrates significantly improved photocatalytic activity for water oxidation and reduction reactions under visible light irradiation (λ ≥ 400 nm) than SrTaO2N, approaching an apparent quantum efficiency as high as 3.4% at 420 ± 20 nm.
研究领域:
材料科学
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能源化学
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2020
·Vol. 7
·期 12
·2343-2351
·
IF 5.958
Ran Wang,Guoan Lin,Xiaoxiang Xu
La/Zr co-doped SrTaO2N has been investigated as visible-light-active photocatalysts for water reduction. Unlike previous aliovalent doping that leads to a decrease in light absorption, La/Zr co-doping largely preserves the visible light absorption of SrTaO2N. More importantly, the La/Zr co-doping not only helps to improve surface hydrophilicity and reduce particle sizes but also effectively inhibits defect formation (e.g. Ta4+) in SrTaO2N. These modifications are responsible for significant enhancements in photocatalytic H2 production. AQE as high as 0.84% was achieved at 420 ± 20 nm for Sr0.4La0.6Ta0.4Zr0.6O2N (x = 0.6), which also showed good durability and stability. Further analysis suggests that La/Zr co-doping negatively shifts the conduction band edge positions of SrTaO2N and contributes to better charge separation conditions.
研究领域:
材料科学
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能源化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Yawei Wang,Shunhang Wei,Xiaoxiang Xu
Solid solutions between SrTaO 2 N and CaTaO 2 N, i.e. Sr 1-x Ca x TaO 2 N (0.0 ≤ x ≤ 1.0) were synthesized and investigated as photocatalysts for water oxidation and reduction. A wealth of important parameters such as Ta-(O, N) bond length, Ta-(O, N)-Ta bond angle, band gap and band edge positions can be successively tuned by varying Sr/Ca molar ratios at A site. These solid solutions work well as photocatalysts to drive water splitting reactions under visible light illumination which clearly outperform their parent compounds SrTaO 2 N and CaTaO 2 N. Apparent quantum efficiency as high as 1.67% at 420 ± 20 nm was achieved on Sr 0.4 Ca 0.6 TaO 2 N (x = 0.6) which stands as the highest one reported for SrTaO 2 N and CaTaO 2 N to date. This simple approach by cation control at A site serves as a useful tool to tailor photocatalytic properties of perovskite oxynitrides, opening new playgrounds for the design and development of these tempting compounds as efficient photocatalysts.
研究领域:
材料科学
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光催化化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2017
·
IF 2.986
Shan-Lu Chen,Wei-Ming Guo,Shi-Kuan Sun,Yuji Masubuchi,Ming Lv,Hua-Tay Lin,Cheng-Yong Wang
In this work, nearly single phase SrTaO 2 N powder was directly prepared from strontium carbonate (SrCO 3 ) and tantalum mononitride (TaN), instead of the nitridation of the oxide precursors using NH 3 . The phase evolution and reaction mechanism together with the chemical composition, crystal structure and particle size of SrTaO 2 N product were investigated. Similar to the reactions between SrCO 3 and Ta 3 N 5 , the evolution of CO 2 , CO and N 2 was detected during the reactions. The results revealed that this novel reaction was able to successfully synthesize orange-coloured SrTaO 2 N powder with nearly pure phase at 1200 °C and the powder possessed the uniform size distribution with the mean diameter of 6.63 µm.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2026
·
IF 6
Yuanfeng Zhu,Nan Li,Deng Li,Hai Zou,Beibei Dong,Yu Qi,Lidong Gong
SrTaO 2 N is an attractive photocatalyst for solar water splitting due to its wide visible light absorption and suitable conduction/valence band position. The formation of porous single crystals is beneficial for the migration of photogenerated carriers from the bulk to the surface. However, the photocatalytic activity is still severely hindered by its intrinsic defects generated during the synthesis process. In this work, Al is selected as the dopant to replace part of Ta sublattice without changing the mesoporous single-crystal characteristics of SrTaO 2 N, in order to address the limitation by reducing the concentration of (such as Ta 4+ ). Based on the above findings, the charge separation is promoted, thereby enhancing photocatalytic proton reduction under visible light illumination. Under optimal conditions, the Al-doped SrTaO 2 N exhibits a stable H 2 evolution rate, which is seven times higher performance than that of SrTaO 2 N, so as to the activity increase of photocatalytic Z-scheme overall water splitting when using them as the H 2 -evloving photocatalyst. Besides, theoretical calculations indicated that the smaller Gibbs free energy and stronger catalyst-methanol interaction caused by Al doping compared with pristine SrTaO 2 N are the main reasons for the improved photocatalytic hydrogen production performance. These results verify that Al is an effective dopant for modifying the photocatalytic potential of Ta-based oxynitrides.
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Weixuan Zeng,Sheng Cao,Lulu Qiao,Anquan Zhu,Pengfei Tan,Yongjin Ma,Yuan Bian,Rui Dong,Ziyu Wang,Jun Pan
Rationally and skillfully constructing semiconductor heterostructured photocatalysts , benefited from the facilitated the carrier separation and transfer, have attracted intensive attention and been demonstrated as a manageable and effective strategy to develop high-performance photocatalysts. Herein, a novel SrTaO 2 N/Ta 3 N 5 heterostructured photocatalyst were fabricated by one-pot nitridation of Sr 2 Ta 2 O 7 /Ta 2 O 5 precursor under ammonia flow. The as-prepared SrTaO 2 N/Ta 3 N 5 is a type-II heterostructure with an intimate interface contact, and the photocatalytic hydrogen production over the optimized heterostructure SrTaO 2 N(0.1)/Ta 3 N 5 is about 14.1 times higher than that of individual SrTaO 2 N. The experimental results suggest that the formation of type-II heterostructure and intimate interface contact between Ta 3 N 5 and SrTaO 2 N accelerates the separation and transfer of electrons and holes under visible light irradiation, consequently contribute to the improved hydrogen production rate. Moreover, we highlight that one-pot nitridation has the great potential to apply as an underlying general strategy of designing and fabricating other types of high-efficiency tantalum oxynitride-based heterostructured photocatalysts.
研究领域:
材料科学
·
光催化
·
无机化学
·
能源化学
·
半导体物理
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）