ChemSusChem
·
2016
·Vol. 9
·期 12
·1403-1412
·
IF 7.116
Yinghao Xie,Yawei Wang,Zuofeng Chen,Xiaoxiang Xu
Graphical Grounds for defecting : Superior photocatalytic activity of Mg-doped Ta 3 N 5 is attributed to the accumulation of oxygen species and the elimination of nitrogen vacancies. The oxygen species lead to the formation of delocalized shallow donor states near the conduction band minimum whereas nitrogen vacancies are responsible for localized deep states in the band gap of Ta 3 N 5 . Tantalum nitride (Ta 3 N 5 ) highlights an intriguing paradigm for converting solar energy into chemical fuels. However, its photocatalytic properties are strongly governed by various intrinsic/extrinsic defects. In this work, we successfully prepared a series of Mg-doped mesoporous Ta 3 N 5 using a simple method. The photocatalytic and photoelectrochemical properties were investigated from the viewpoint of how defects such as accumulation of oxygen and nitrogen vacancies contribute to the catalytic activity. Our findings suggest that Mg doping is accompanied by an accumulation of oxygen species and a simultaneous elimination of nitrogen vacancies in Ta 3 N 5 . These oxygen species in Ta 3 N 5 induce delocalized shallow donor states near the conduction band minimum and are responsible for high electron mobility. The superior photocatalytic activity of Mg-doped Ta 3 N 5 can then be understood by the improved electron–hole separation as well as the lack of nitrogen vacancies, which often serve as charge-recombination centers.
研究领域:
材料科学
·
光化学
·
催化
·
太阳能转换
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Yuwei Zhang,Lulu Kong,Elena Yu. Konysheva,Xiaoxiang Xu
The separation of photocarriers (e - and h + ) is of critical importance in initiating efficient catalytic reactions over semiconductor-based photocatalysts . Although heterostructures have been frequently built to separate photocarriers, the lack of proper heterogeneous interfaces greatly limits their efficacies. Here, we show that excellent heterogeneous interfaces can be built for in situ fabricated Ta 3 N 5 @CaTaO 2 N heterostructures. These interfaces are characterized by perfectly matching (020) crystal facets of Ta 3 N 5 and CaTaO 2 N, offering ideal channels for charge transportation. As revealed by both experimental and theoretical analysis, these seamless interfaces enable rapid spatial photocarrier separation, which in turn, contribute to exceptional photocatalytic activity . Under optimal conditions, Ta 3 N 5 @CaTaO 2 N heterostructures achieve apparent quantum efficiency as high as 14.52% at 420 ± 20 nm for O 2 -evolution, substantially surpassing Ta 3 N 5 , CaTaO 2 N, and their mixtures. These results not only justify the importance of heterogeneous interfaces for photocarrier separation but also invigorate more attention upon heterostructures towards efficient solar water splitting.
研究领域:
光催化
·
材料科学
·
可再生能源
·
半导体物理
·
太阳能转换
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Yawei Wang,Dazhang Zhu,Xiaoxiang Xu
Tantalum nitride (Ta3N5) has been considered as a promising candidate for photocatalytic water splitting because of its strong visible-light absorbance as far as 600 nm. However, its catalytic activity is often hampered by various intrinsic/extrinsic defects. Here, we prepared a series of Zr-doped mesoporous tantalum nitride (Ta3N5) via a template-free method and carried out a detailed investigation of the role of Zr doping upon the photocatalytic performance. Various physicochemical properties including crystal structure, optical absorption, and so on were systematically explored. Our results show that doping Zr into Ta3N5 induces an enhancement of oxygen content and a suppression of absorption band around 720 nm, indicating an increase of ON• defects and a decrease of VN••• defects in the structure. Introduction of Zr significantly boosts the photocatalytic oxygen production of Ta3N5. The optimized photocatalytic oxygen production rate approaches 105 μmol h–1 under visible light illumination (λ ≥ 420 nm), corresponding to an apparent quantum efficiency as high as 3.2%. Photoelectrochemical analysis and DFT calculation reveal that the superior photocatalytic activity of Zr-doped Ta3N5 originates from a high level of ON• defects’ concentration, which contributes to a high electron mobility, and a low level of VN••• defects’ concentration, which often act as charge recombination centers.
研究领域:
光催化
·
材料科学
·
能量转换
·
缺陷化学
·
半导体物理
✓ 已验证
DOI
高影响因子
Chemical Science
·
2023
·Vol. 15
·期 3
·896-905
·
IF 8.4
Xiaodong Wang,Huijuan Zhang,Chuanzhen Feng,Yu Wang
Efficient carrier separation is important for improving photoelectrochemical water splitting. Here, the morphology modification and band structure engineering of Ta3N5 are accomplished by doping it with Cu and Zr using a two-step method for the first time. The initially interstitially-doped Cu atoms act as anchors to interact with subsequently doped Zr atoms under the influence of differences in electronegativity. This interaction results in Cu,Zrg–Ta3N5 having a dense morphology and higher crystallinity, which helps to reduce carrier recombination at grain boundaries. Furthermore, the gradient doping of Zr generates a band edge energy gradient, which significantly enhances bulk charge separation efficiency. Therefore, a photoanode based on Cu,Zrg–Ta3N5 delivers an onset potential of 0.38 VRHE and a photocurrent density of 8.9 mA cm−2 at 1.23 VRHE. Among all the Ta3N5-based photoanodes deposited on FTO, a Cu,Zrg–Ta3N5-based photoanode has the lowest onset potential and highest photocurrent. The novel material morphology regulation and band edge position engineering strategies described herein provide new ideas for the preparation of other semiconductor nanoparticles to improve the photoelectrochemical water splitting performance.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2026
·Vol. 27
·期 18
·8281
·
IF 5.6
Haoran Zhang,Siqi Sun,Shaoxuan Zhang,Jianjun Liao,Shiwei Lin
Ta3N5is a promising material for overall water splitting due to its suitable band positions and high theoretical photocurrent (12.9 mA cm−2). However, pristine Ta3N5suffers from significant optical, recombination, and resistive losses, resulting in photocurrents and efficiencies far below theoretical expectations. To address these limitations, this work focuses on enhancing photocurrent and overall performance through structural and morphological engineering and surface functionalization. We investigated the potential of polyelectrolytes, poly(sodium-p-styrenesulfonate) (PSS) with anionic groups and poly(diallyl-dimethylammonium chloride) (PDDA) with cationic groups, as a hole transport layer material in Ta3N5pyramid arrays photoelectrodes for enhanced photoelectrochemical water splitting. We synthesized pyramid-shaped Ta3N5using Na2Ta2O6as a template. The polyelectrolyte combined with catalysts was used to modify Ta3N5to improve charge separation and injection efficiency. After systematically investigating the effect of the polyelectrolyte modification sequence on the photoelectrode, the champion sample Ta3N5-PDDA3PSS3-Co(OH)xdelivers a photocurrent density of 7.7 mA cm−2at 1.23 V vs. RHE under simulated solar illumination, which is over 7-fold higher than that of pristine Ta3N5. This work demonstrates that polymer functionalization of nitride semiconductors enables efficient solar-to-fuel conversion.
✓ 已验证
DOI
高影响因子
ACS Applied Energy Materials
·
2018
·
IF 0
Lang Pei,Bihu Lv,Shuangbao Wang,Zhentao Yu,Shicheng Yan,Ryu Abe,Zhigang Zou
Developing photoanodes that can split water with low (or even without) externally applied bias is a critical challenge for achieving efficient solar-driven photoelectrochemical water oxidation. Here, we proposed a flux-assisted oriented crystal growth route to minimize the drawbacks of Ta3N5 photoanode, including the following: (1) Crystallographic-oriented growth minimizes the negative effect of electronic structure anisotropy of the Ta3N5, facilitating the directional fast charge transfer in having lighter carrier effective mass of (b,c)-axes directions. (2) Reducing crystal defects suppressed surface recombination of carriers and released the surface Fermi level pinning effect. (3) Increment of oxygen-impurity electron donor by Sc doping improved the electrical conductivity, promoting the bulk charge separation and transfer. Specifically, the onset potential of Ta3N5 photoanode was dramatically negatively shifted to 0.4 VRHE, and thereby afforded a 0.82% half-cell solar-to-hydrogen efficiency.
研究领域:
材料科学
·
光电化学
·
可再生能源
·
半导体物理
✓ 已验证
DOI
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
JOURNAL OF MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 41
·21972-21978
·
IF 5.968
Zheng Wang,Jungang Hou,Shuqiang Jiao,Kai Huang,Hongmin Zhu
Photocatalytic oxygen evolution with a high efficiency was achieved using tantalum nitride (Ta3N5) quantum dots (QDs) coupled TaON hollow spheres (Ta3N5–TaON). TaON hollow spheres coupled with the surface enriched Ta3N5 QDs were prepared by an in situ chemical reduction route in ammonia solution at −45 °C and were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectra, UV-vis diffuse reflectance spectra and photoluminescence spectra. The Ta3N5–TaON composites containing 4 mol% Ta3N5 QDs showed a high rate of O2 production at 208.2 μmol h−1 with an apparent quantum efficiency of 67% under 420 nm light. The rate of oxygen formation of the Ta3N5–TaON heterojunction was 3.3 times higher than that of the pristine TaON hollow spheres. Furthermore, relative photoelectrochemical properties of Ta3N5–TaON composite photoelectrodes were investigated. The resulting 4 mol% Ta3N5–TaON heterojunction films exhibited a photocurrent of ca. 2.7 mA cm−2 under visible light irradiation at 1.0 V vs. SCE in Na2SO4 solution. This excellent photocatalytic activity is ascribed to the Ta3N5 QDs that alter the energy levels of the conduction and valence bands in the coupled semiconductor system and the slow recombination of photogenerated electron–hole pairs. Moreover, the Ta3N5–TaON composite exhibited strong durability which could be attributed to the inhibition of Ta3N5 QDs leaching owing to its strong interaction with TaON.
研究领域:
光催化
·
材料科学
·
能量转换
·
半导体异质结构
·
太阳能利用
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2020
·
IF 16.683
Yilong Yan,Yijing Gao,Haiyang Zheng,Bowen Yuan,Qiaoqiao Zhang,Yu Gu,Guilin Zhuang,Zhongzhe Wei,Zihao Yao,Xing Zhong,Xiaonian Li,Jianguo Wang
OH radicals produced via an eco-friendly O 3 decomposition reaction in water are employed in a wide range of applications. In this work, three-dimensional (3D) β-PbO 2 /Ta 2 O 5 and Pt/Ta 3 N 5 samples with a rod-like morphology were successfully fabricated and coupled to carry out electrochemical ozone production (EOP) and hydrogen evolution reaction (HER), respectively. Moreover, the results on the in-situ electrodegradation of dimethoate also indicate that the β-PbO 2 /Ta 2 O 5 NRs show a great potential to be used in advanced oxidation processes (AOPs) applications. Experimental results and theoretical calculations reveal that the excellent EOP performance of the β-PbO 2 /Ta 2 O 5 NRs can be attributed to the adsorption energy of the O species, which can be modulated via the synergic effect between β-PbO 2 and Ta 2 O 5 . This work provides a reference for the development of stable electrocatalysts with high efficiency for the simultaneous production of O 3 and H 2 in environmental applications and energy conversion.
研究领域:
电化学
·
环境科学
·
材料科学
·
能源转换
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2025
·Vol. 49
·期 20
·8485-8493
·
IF 2.5
Jiudi Zhang,Ruyu Zhang,Xiaowei Jia,Jinming Li,Mingliang Sun,Shikang Zhang,Zhenfu Guo,Xiaoyan Jiao,Xianchun Liu,Zhanshuang Jin,Junjie Li,Yan Xing
Tantalum nitride (Ta3N5) with suitable band structure and high theoretical solar-to-hydrogen energy conversion efficiency (15.9%) is regarded as one of the most promising semiconductor-based photocatalysts for hydrogen evolution via water splitting. However, it is practically constrained by the slow carrier mobility, fast electron–hole recombination and unabundant catalytic active sites. Herein, honeycomb-structured Ta3N5 foam nanoplates were successfully synthesized using a simple template-free strategy. It can not only capture broader visible light to generate the high concentration of photo-generated carriers, but also accelerate the rapid transport/separation of carriers and provide abundant active sites to accelerate the kinetics of water splitting reaction. Therefore, honeycomb-structured Ta3N5 exhibits excellent photocatalytic performance with a remarkably enhanced H2 production rate of 59.16 μmol h−1 g−1, which is 22.7 times higher than that of the conventional bulk Ta3N5. Moreover, the unique Ta3N5 with honeycomb structure has outstanding stability and recycling ability. This work provides a simple and effective strategy for the preparation of Ta3N5-based photocatalysts for efficient and stable H2 production.
研究领域:
材料科学
·
纳米技术
·
能量转换
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）