APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Jishu Han,Fangxu Dai,Ying Liu,Ruiyang Zhao,Lei Wang,Shouhua Feng
The photocatalytic hydrogen production has become one of the most promising strategies to solve the energy crisis and environmental pollution. Novel CdSe/SrTiO 3 nanocomposites (average diameter ≈ 114.6 nm) with high photocatalytic activity are synthesized and used for visible light photocatalytic water splitting for hydrogen production . Through optimizing the concentration of CdSe QDs, CdSe/SrTiO 3 nanocomposites exhibit increased visible light absorption and enhanced photocatalytic hydrogen evolution efficiency compared to SrTiO 3 nanoparticles. The maximum H 2 evolution amount reaches to 3350.53 μmol in 8 h by using CdSe/SrTiO 3 -3 as catalyst. Owing to the formation of heterojunction at the interface between CdSe and SrTiO 3 , the electrochemical impedance spectrum of CdSe/SrTiO 3 -3 exhibits the smallest arc radius and the photocurrent density of CdSe/SrTiO 3 -3 reaches to 0.26 μA cm −2 . The photogenerated electrons are effectively separated and transferred and the recombination of electron-hole pairs is avoided, thus significantly improving the photocatalytic hydrogen production performance of CdSe/SrTiO 3 nanocomposites.
研究领域:
材料科学
·
物理化学
·
纳米催化
·
能源材料
·
光催化
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2012
·Vol. 22
·期 15
·7291-7299
·
IF 5.968
Jungang Hou,Zheng Wang,Wenbin Kan,Shuqiang Jiao,Hongmin Zhu,R. V. Kumar
Large-scale hydrogen production through water splitting using photocatalysts with solar energy can potentially produce clean fuel from renewable resources. In this work, photocatalytic evolution of H2 with a high efficiency was achieved using graphene oxide (GO) nanosheets decorated with CdS sensitized TaON core–shell composites (GO–CdS@TaON). The CdS@TaON core–shell nanocomposites were prepared by an ion-exchange route with assistance from a hydrothermal process on GO as the support. The TaON core–shell composites containing 1 wt% CdS nanocrystals showed a high rate of H2-production at 306 μmol h−1 with an apparent quantum efficiency (QE) of 15% under 420 nm monochromatic light. The rate of hydrogen formation was 68 times faster in comparison with the rate observed on pure TaON. The rate was further increased to 633 μmol h−1 with a high quantum efficiency of 31% when the GO–CdS@TaON hybrid composite was coupled with 1 wt% of graphene oxide and 0.4 wt% of Pt (about 141 times higher than that of the pristine TaON). This high photocatalytic H2-production activity is ascribed firstly to the presence of CdS nanocrystals that alter the energy levels of the conduction and valence bands in the coupled semiconductor system; secondly to the involvement of graphene oxide that serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS@TaON composites. This investigation can open up new possibilities for the development of highly efficient TaON-based photocatalysts that utilize visible light as an energy source.
研究领域:
材料化学
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光催化
·
能源科学
·
纳米材料
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半导体物理
·
可再生能源
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Lingwei Lu,Meilin Lv,Gang Liu,Xiaoxiang Xu
Constituting solid solutions has been an appealing means to gain control over various physicochemical properties. In this work, we synthesized a series of SrTiO 3 -BiFeO 3 solid solutions and systematically explored their structural, optical and photocatalytic properties. Our results show that all solid solutions crystallize in a primitive cubic structure and their band gap values can be easily tuned by adjusting molar ratios between SrTiO 3 and BiFeO 3 . Photocatalytic hydrogen production under both full range and visible light irradiation is greatly improved after forming solid solutions. The highest hydrogen production rate obtained is ∼180 μmol/h under full range irradiation (λ ≥ 250 nm) and ∼4.2 μmol/h under visible light irradiation (λ ≥ 400 nm), corresponding to apparent quantum efficiency ∼2.28% and ∼0.10%, respectively. The activity is found to be strongly influenced by surface area and light absorption. Theoretical calculation suggests that Fe contributes to the formation of spin-polarized bands in the middle of original band gap and is responsible for the band gap reduction and visible light photocatalytic activity .
研究领域:
材料化学
·
光催化
·
能源材料
·
无机固体化学
·
半导体物理
·
太阳能转化
·
表面科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2019
·
IF 3.131
Xiaotong Sun,Luting Yan,Runxiang Xu,Mingyuan Xu,Yanyun Zhu
TiO 2 presents a broad application prospect in the field of degradation of environmental pollutants. However, the development of TiO 2 photocatalyst has been limited by two factors, namely, narrow spectral response range and low quantum efficiency . Surface coating can selectively change the physical and chemical properties of core particles, whereas the synergistic action between core and shell can optimize material performance. In this paper, surface modification of titanium dioxide (TiO 2 ) by dopamine polymerization was used to improve its photocatalytic performance. Among polydopamine (PDA)-modified TiO 2 , TiO 2 @PDA-0.4 mg/mL-2 h showed the best degradation rate of Rhodamine B (RhB): the degradation rate reached 99.28% and 77.40% after 1.5 h of ultraviolet–visible (UV–vis) and visible (Vis) light irradiation, respectively. Compared with the uncoated TiO 2 , the degradation rate has shown improvement, especially under Vis light irradiation, with the photocatalytic performance improving by 35.04%. Absorption, emission, and impedance spectra showed that surface modification of TiO 2 with suitable thickness of PDA effectively increased light absorption and promoted separation of photogenerated carriers . High-performance liquid chromatography–mass spectrometry revealed the differences in photocatalytic degradation mechanism of TiO 2 @PDA to RhB under UV–vis and Vis light irradiation. Compared with those under UV–vis light irradiation, the intermediate products under Vis light irradiation are relatively simple. TiO 2 @PDA generated more electrons, which interacted with H 2 O to produce large amounts of ·OH and holes under UV–vis light irradiation in comparison with that under Vis light irradiation. In addition to deacetylation , deamination , and decarboxylation by hydroxylation , excess ·OH in the photocatalytic process would attack benzene rings directly to produce N , N -diethylacetamide.
研究领域:
材料科学
·
环境化学
·
光催化
·
纳米材料
·
表面工程
✓ 已验证
DOI
高影响因子
Journal of Energy Chemistry
·
2020
·
IF 7.216
Jinxing Yu,Xiaoxiang Xu
Cr doped Ruddlesden-Popper compound Sr 2 TiO 4 has been successfully modified by fluorine to form a new compound Sr 2 Ti 0.95 Cr 0.05 O 3 F 2 . Structure analysis suggests two types of fluorine in the structure of this new compound, i.e. intralayer and interlayer F, which induce strong built-in electric field within this layered compound. The electric field stems from uneven distribution of F atoms on the two sides of perovskite layers therefore leads to charge disproportionation . DFT calculations suggest that this unique structural feature is highly beneficial for charge dissociations as it breaks the coplanar settlement of conduction band minimum and valence band maximum whilst maintains the 2D charge transportation properties. This is clearly demonstrated by the superior photocatalytic activities of Sr 2 Ti 0.95 Cr 0.05 O 3 F 2 for hydrogen production from water. Apparent quantum efficiency (AQE) as high as 1.16% at 420 ± 20 nm has been achieved which stands as the highest AQE reported on Sr 2 TiO 4 to date. Photoelectrochemical (PEC) analysis confirms improved charge separation conditions and prolonged charge lifetime.
研究领域:
材料化学
·
光催化
·
能源化学
·
物理化学
·
无机功能材料
·
太阳能转化
·
环境科学
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Xi-Ming Song,Xin Zhou,Chunxue Yuan,Yu Zhang,Qiang Tong,Ying Li,Luxia Cui,Daliang Liu,Wei Zhang
We reported a novel Fe 2 O 3 /rutile TiO 2 nanorod (NR) arrays with the heterogeneous structure for photoelectrochemical (PEC) cells, which were fabricated on fluorine-doped tin oxide glass (FTO) substrates that serve as model architecture via a hydrothermal method. Fe 2 O 3 was revealed as an inexpensive and eco-friendly semiconductor sensitizer to make TiO 2 respond to visible light . By using this photoanode, the photoelectric conversion and water splitting properties of PEC cells based on the one-dimensional (1D) Fe 2 O 3 /TiO 2 heterostructures were investigated in detail under simulated sunlight. Meanwhile, the optimization of photovoltaic performance was also achieved by regulating the amount of Fe 2 O 3 . The open circuit voltage and short circuit current of the Fe 2 O 3 /TiO 2 solar cell can reach 0.435 V and 1.840 mA/cm 2 , respectively. In addition, theoretical analysis of the photoelectric effect is preliminarily explored on the basis of the flat band potential results.
研究领域:
材料科学
·
物理化学
·
能源科学
·
纳米科技
·
光催化
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）