MATERIALS & DESIGN
·
2019
·
IF 5.77
Yi-lei Li,Ying Liu,Ying-juan Hao,Xiao-jing Wang,Rui-hong Liu,Fa-tang Li
Core-shell heterostructured BiVO 4 @Fe 2 O 3 photocatalysts are fabricated through a facile solution combustion and in-situ precipitation methods. Transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) images verify their core-shell structure. X-ray photoelectron spectroscopy (XPS) results indicate there are interaction between BiVO 4 and Fe 2 O 3 , confirming the formation of heterojunction. Mott–Schottky measurements exhibit that hybridizing with Fe 2 O 3 makes the conduction band of BiVO 4 to be shifted up by 1.05 V from 0.21 to −0.84 V, which endows BiVO 4 to be effective for photocatalytic H 2 generation. Meanwhile, photoluminescence spectra show that the heterosturcture decreases the recombination efficiency of photo-induced electrons and holes. Hydrogen experiments indicate that BiVO 4 @Fe 2 O 3 composite containing 10 wt% Fe 2 O 3 has the highest catalytic activity.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
MATERIALS SCIENCE IN SEMICONDUCTOR PROCESSING
·
2022
·
IF 4.644
Yuewen Li,Yu Zhang,Xing Hou,Chunkun Lin,Degang Bu,Yalin Lan,Na Li,Shuyao Wu,Shuo Li,Xi-Ming Song
Seeking novel solar energy utilization and conversion methods has always been a frontier topic in energy research. Here, we propose a new way to directly photoelectrodeposit metals using solar energy based on semiconductor energy band theory . Three kinds of semiconductor photoanodes (TiO 2 , BiVO 4 and Fe 2 O 3 ) are employed to deposit metallic Cu or Bi at the cathode under illumination without external voltage. It is found that when TiO 2 and BiVO 4 are used as photoanodes, Cu, Cu 2 O and Bi can be continuously deposited on the cathode, but when Fe 2 O 3 photoanode is irradiated, no material comes out. The results prove that the potential of electrons in the conduction band determines whether photoelectric deposition occurs or not. The related mechanism involves the oxygen reduction reaction (OER) of the valence band holes of the photoanode, the collection of conduction band electrons by back electrode, as well as the reduction of metal ions on the counter electrode. In addition, we also put forward the concept of using the deposited Cu or Bi as the metal electrode to form a new metal-air battery to release chemical energy of the deposited metal.
研究领域:
材料科学
·
能源研究
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2020
·
IF 6.182
Qing Cheng,Wulin Yang,Qingling Chen,Jiajun Zhu,Deyi Li,Licai Fu,Lingping Zhou
Maintaining a highly negative value of conduction band (CB) potential of photocatalysts through metal doping has been a great challenge. Herein, we investigated the effects of Fe-doping on the crystal structures and electronic structures of zirconia (ZrO 2 ) in detail by combining experiments and Density Functional Theory (DFT). It was revealed that the Fe-doping obviously triggered the formation of tetragonal phase ZrO 2 and induced a defect states in the bandgap of Fe-doped ZrO 2 . Due to the coherent effect between the electrons of the Fe 3 d orbitals and ZrO 2 intrinsic electronic states, the defect states expanded the light absorption edge of ZrO 2 and Fe-doped ZrO 2 showed a small bandgap with maintaining a highly negative value of the CB potential. Meanwhile, Fe-doping significantly enhanced photoelectrochemical properties, the efficiency separation of electron-hole pairs and photocatalytic activity in comparison with the pristine ZrO 2 . We also found that 0.5%Fe-ZrO 2 exhibited the optimum photocatalytic performance, and reached 96% for degradation of Rhodamine B (RhB) within 150 min under visible light irradiation. This work elucidated the mechanism of the photocatalytic degradation of RhB over Fe-doped ZrO 2 and provided a promising approach in designing highly negative CB potential of ZrO 2 via Fe doping toward sustainable environmental remediation.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Ting Song,Piyong Zhang,Jian Zeng,Tingting Wang,Atif Ali,Heping Zeng
Metal-organic framework (MOF) materials with their synthetic tunability and structural regularity offer an interesting platform to achieve photocatalytic H 2 production. To determine whether metal ions in MOF materials affect the photocatalytic hydrogen (H 2 ) evolution activity, very few studies investigated MOF materials having the same crystal structures and ligands. In this study, we describe the synthesis of isostructural MOF materials. Cadmium (II) or copper (II) were linked with the 4′-(2,4-disulfophenyl)-3,2′:6′,3″-terpyridine (H 2 DSPTP) organic ligand to form Cd-MOFs and Cu-MOFs, respectively. Although Cd-MOFs and Cu-MOFs had the same valence band (VB) energy, the conduction band (CB) level of Cu-MOFs was more negative than that of Cd-MOFs. Therefore, the reduction ability of Cu-MOFs was greater than that of Cd-MOFs. Moreover, Cu-MOFs showed excellent absorption of visible and even near-infrared (NIR) radiation, because it has strong metal-to-ligand charge transfer (MLCT) character. Interestingly, the rate of photocatalytic H 2 generation was 18.96 μmol h −1 in the presence of Cu-MOFs, which were irradiated with NIR light ; however, Cd-MOFs did not report any such activity. Moreover, the performance and stability of Cd-MOFs were different from that of Cu-MOFs. In this study, the proof of knowledge for rational photocatalyst design introduced here furnishs the notional framework for constructing high-activity MOF materials.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2025
·
IF 5.4
Dusu Wen,Xing Xing,Yuanman Wang
In this study, BiV 1- x M x O 4 (M = Sc, Ti, W, Mo; x = 0, 0.005, 0.01, 0.02, 0.03, 0.05, 0.07, 0.10) samples with monoclinic structure were successfully synthesized by the conventional solid state reaction method, and the doping effects on the crystal structure, band structure and optical properties were investigated. XRD and Rietveld refinement results suggested the formation of solid solutions with monoclinic structure in low concentration range. UV–vis diffuse reflectance, XPS and VBXPS results revealed that the band structure of BiVO 4 could be adjusted by doping elements with different electronegativities into V site. It is found that the energy level of CBM raised by doping Sc and Ti which have lower electronegativities than V, and the energy level of CBM decreased by doping W and Mo which have higher electronegativities than V.
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2014
·
IF 2.2
Zhenlong Zhang,Jichun Zhu,Shengjun Li,Yanli Mao
SrTiO 3 /Bi 2 O 3 heterojunction semiconductor was prepared and characterized by X-ray diffraction, UV–vis absorption spectrum , and scanning electron microscope, surface photovoltage spectroscopy, and photoluminescence spectroscopy. The surface photovoltage spectra indicate that the separation efficiency of photoinduced charges for SrTiO 3 /Bi 2 O 3 was enhanced compared with that of SrTiO 3 or Bi 2 O 3 . The energy band diagram of SrTiO 3 /Bi 2 O 3 heterojunction was directly determined with X-ray photoelectron spectroscopy, and the conduction band offset between SrTiO 3 and Bi 2 O 3 was quantified to be 0.28±0.03 eV. The photoluminescence spectra display that the recombination rate of photoinduced carriers for SrTiO 3 /Bi 2 O 3 decreases compared with that of SrTiO 3 or Bi 2 O 3 , which is mainly due to the energy levels matching between them. Therefore the enhanced separation efficiency of photoinduced charges is resulting from the energy difference between the conduction band edges of SrTiO 3 and Bi 2 O 3 .
研究领域:
材料科学
·
光催化
✓ 已验证
产品关联
DOI
高影响因子
ACS Nano
·
2015
·
IF 12.881
Shuang Jiao,Qing Shen,Iván Mora-Seró,Jin Wang,Zhenxiao Pan,Ke Zhao,Yuki Kuga,Xinhua Zhong,Juan Bisquert
Even though previously reported CdTe/CdSe type-II core/shell QD sensitizers possess intrinsic superior optoelectronic properties (such as wide absorption range, fast charge separation, and slow charge recombination) in serving as light absorbers, the efficiency of the resultant solar cell is still limited by the relatively low photovoltage. To further enhance photovoltage and cell efficiency accordingly, ZnTe/CdSe type-II core/shell QDs with much larger conduction band (CB) offset in comparison with that of CdTe/CdSe (1.22 eV vs 0.27 eV) are adopted as sensitizers in the construction of quantum dot sensitized solar cells (QDSCs). The augment of band offset produces an increase of the charge accumulation across the QD/TiO2 interface under illumination and induces stronger dipole effects, therefore bringing forward an upward shift of the TiO2 CB edge after sensitization and resulting in enhancement of the photovoltage of the resultant cell devices. The variation of relative chemical capacitance, Cμ, between ZnTe/CdSe and reference CdTe/CdSe cells extracted from impedance spectroscopy (IS) characterization under dark and illumination conditions clearly demonstrates that, under light irradiation conditions, the sensitization of ZnTe/CdSe QDs upshifts the CB edge of TiO2 by the level of ∼50 mV related to that in the reference cell and results in the enhancement of Voc of the corresponding cell devices. In addition, charge extraction measurements have also confirmed the photovoltage enhancement in the ZnTe/CdSe cell related to reference CdTe/CdSe cell. Furthermore, transient grating (TG) measurements have revealed a faster electron injection rate for the ZnTe/CdSe-based QDSCs in comparison with the CdSe cells. The resultant ZnTe/CdSe QD-based QDSCs exhibit a champion power conversion efficiency of 7.17% and a certified efficiency of 6.82% under AM 1.5G full one sun illumination, which is, as far as we know, one of the highest efficiencies for liquid-junction QDSCs.
研究领域:
材料科学
·
纳米技术
·
太阳能
·
光伏
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2024
·
IF 20.2
Fu Li,Qian Huo,Xiaomei Zhou,Shasha Fang,Fei Han,Jingnan Yang,Qingxin Guan,Wei Li
Photothermal CO 2 into methanol is an effective approach to address energy and environmental challenges, but the low conversion and poor selectivity limit its large-scale application. Here, 0.5Cu@CeO 2 with atomically dispersed active sites and abundant Frustrated-Lewis-pairs (FLPs) was synthesized using coordination complex precipitation reaction. The substitution of Cu 2+ with Ce 3+ results in the formation of new FLPs, which promotes the upward shift of conduction band (CB) and enhances the reducing capability of catalyst. Moreover, the more sensitive and stronger capability of photogenerated carriers also endows 0.5Cu@CeO 2 with stronger CO 2 reduction capability. The photothermal methanol yield of 0.5Cu@CeO 2 reached 1896.02 μmol·g cat –1 ·h –1 . The DFT results demonstrate the FLPs structure of 0.5Cu@CeO 2 promotes parallel adsorption of CO 2 and *CO species. Meanwhile, the presence of O v inhibits the dissociation of oxygen species, consequently boosting the methanol synthesis. The construction of FLPs structure introduces a novel method to enhance CO 2 conversion utilizing photothermal catalysis.
研究领域:
催化
·
材料科学
·
环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 9
·期 14
·3578-3589
·
IF 7.779
Jie-hao Lia,Rui-hong Liu,Meng Ning,Yi-lei Li,Ying Liu,Xinying Liu,Phathutshedzo Khangale,Diane Hildebrandt,Xiao-jing Wang,Fa-tang Li
Constructing heterostructured photocatalysts will generally improve the separation efficiency of photo-induced carriers; however, the change in the energy band position that affects their redox ability has received little attention. In this work, α-Bi2O3/Bi5NO3O7 heterojunctions are prepared via solution combustion synthesis and characterized by UV-vis DRS, Mott–Schottky and Kelvin probes, and the band structures of α-Bi2O3 and Bi5NO3O7 before and after the formation of the heterojunction are obtained. The results of the degradation of rhodamine B and tetracycline indicate that the main active species are holes and superoxide anion radicals, respectively. Although separation efficiency over heterojunctions is higher than that over individual Bi5NO3O7 and α-Bi2O3, lower degradation ability is observed. The reason is that the heterojunction formation causes an upward shift of the valence band of Bi5NO3O7 and a downward shift of the conduction band of α-Bi2O3, which reduces the oxidation ability of holes and the ability to activate molecular oxygen, respectively. The decrease in the redox ability outweighs the positive impact of enhanced separation efficiency.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2021
·
IF 9.127
Youxu Yu,Fengjia Xie,Rong Chen,Xun Zhu,Qiang Liao,Dingding Ye,Jinwang Li,Sihong Song
The objective of this work is to explore the role of CO 2 in the photocatalytic fuel cell with TiO 2 as the photoanode and methanol as a fuel under acid condition by making the anode electrolyte saturated with CO 2 . It is interesting to find that the performance of the photocatalytic fuel cell can be improved at low methanol concentration in the presence of CO 2 . This is probably because TiO 2 has an adequate conduction band for photocatalytic reduction of CO 2 to organics at the photoanode, which increases the methanol concentration at the catalytic surface to alleviate the mass transfer issue encountered in the low methanol concentration operation, and hinders the recombination of the electron-hole pairs. Moreover, the methanol concentration at the outlet of the photoanode can be even higher than the supplied methanol concentration. However, this effect is weakened and even disappears as the supplied methanol concentration increases. This work gives new insights into the role of CO 2 in the photocatalytic fuel cell with the photoanode having an adequate conduction band for photocatalytic reduction of CO 2 .
研究领域:
能源科学
·
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Dengfeng Luo,Sirui Yang,Wei Zhang,Qing Zhang,Limei Cha,Li Dang,Ming-De Li
Doping metal ions into lead halide perovskite nanocrystals is one of the most efficient strategies to control their photoelectric properties. Here, we develop a simple and low-cost route to synthesize the high-quality alkaline-earth metal ion (AE2+)-doped CsPbBr3 nanocrystals at room temperature. The almost 100% promoted photoluminescence quantum yield behavior of AE2+-doped CsPbBr3 nanocrystals is demonstrated by an ultrafast dynamics study and theoretical calculations on the dopant defect formation energies and electronic properties. The AE2+ dopants can promote the radiation recombination of carriers by essentially reducing the carriers trapped into intraband and interband defect states and promote the intraband coupling. Furthermore, Br– and Pb2+ vacancies can be eliminated to enhance the short-range order of the CsPbBr3 lattice and enrich the conduction band edge states, leading to the photoluminescence enhancement of CsPbBr3 nanocrystals. Our studies provide new insights into the mechanism of AE2+-doped effects and present guiding strategies for improving the optical performance of doped perovskite nanocrystals.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2021
·
IF 13.273
Shumin Li,Fan Wu,Rongbin Lin,Jin Wang,Chunxia Li,Zhengquan Li,Jun Jiang,Yujie Xiong
Fe-based metal-organic frameworks (MOFs) have shown promising applications in photocatalysis, yet they are incapable of photocatalytic H 2 production due to their inappropriate conduction band (CB) position and large overpotential for H 2 evolution. Herein, we present a facile strategy enabling the photocatalytic H 2 production over Fe-based MOFs through dye sensitization. A combination of characterization techniques with theoretical simulation reveals that dye sensitization can effectively inject energetic electrons into Fe-MOFs and elevate their quasi-Fermi level under light irradiation, overcoming the surface overpotential for H 2 production from water. Furthermore, deposition of Pt nanoparticles on Fe-MOFs can lower the overpotential for H 2 evolution toward further enhanced photocatalytic activity. This work provides insights into MOF band structure engineering at electronic level, and proves a concept that harnesses MOF materials for targeted photocatalytic applications they are originally not fit for.
研究领域:
材料科学
·
化学工程
·
能源科学
✓ 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）