MOLECULES
·
2021
·Vol. 26
·期 22
·6849
·
IF 4.412
Yan Fan,Tao Wang,Yinwei Qiu,Yinli Yang,Qiubo Pan,Jun Zheng,Songwei Zeng,Wei Liu,Gang Lou,Liang Chen
Graphene p-n junctions have important applications in the fields of optical interconnection and low–power integrated circuits. Most current research is based on the lateral p-n junction prepared by chemical doping and other methods. Here, we report a new type of pure graphene oxide (pGO) vertical p-n junctions which do not dope any other elements but only controls the oxygen content of GO. The I–V curve of the pGO vertical p–n junction demonstrates a remarkable rectification effect. In addition, the pGO vertical p–n junction shows stability of its rectification characteristic over long-term storage for six months when sealed and stored in a PE bag. Moreover, the pGO vertical p–n junctions have obvious photoelectric response and various rectification effects with different thicknesses and an oxygen content of GO, humidity, and temperature. Hall effect test results show that rGO is an n–type semiconductor; theoretical calculations and research show that GO is generally a p–type semiconductor with a bandgap, thereby forming a p–n junction. Our work provides a method for preparing undoped GO vertical p–n junctions with advantages such as simplicity, convenience, and large–scale industrial preparation. Our work demonstrates great potential for application in electronics and highly sensitive sensors.Keywords:undoped p–n junction;vertical p–n junction;graphene oxide
研究领域:
材料科学
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电子工程
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产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Mei Dong,Wenjun Li,Liang Geng,Ruixue Huang,Yuan Liu,Hongli Han
Herein, CuCo 2 O 4 hollow porous nanospheres (HPN), nanosheets (NS), and nanowires (NW) were synthesized via solvothermal and calcination processes, and were used to construct efficient heterojunctions with Cd 0.5 Zn 0.5 S. Interestingly, the unique hollow porous structure exhibits enhanced light absorption, large pore diameter (12.57 nm), and strong hydrophilicity (10.05°). Photocatalytic results indicate that CuCo 2 O 4 HPN/Cd 0.5 Zn 0.5 S achieves the optimal hydrogen production rate, which is 5.4, 1.2, and 1.3 times than that of pure Cd 0.5 Zn 0.5 S, CuCo 2 O 4 NW/Cd 0.5 Zn 0.5 S and CuCo 2 O 4 NS/Cd 0.5 Zn 0.5 S, respectively. High-resolution TEM and theoretical calculations confirm that (311)/(111) facet junctions in CuCo 2 O 4 nanospheres form a work function difference (0.24 eV), which significantly facilitates charge transfer and separation. Mott-Schottky and Ultraviolet photoelectron spectroscopy analyses indicate that p-type CuCo 2 O 4 and n-type Cd 0.5 Zn 0.5 S have staggered energy levels and a distinct Fermi level difference (1.85 eV), which leads to rearrangement of the Fermi energy level and modulation of charge transfer pathway. The resulting energy band bending and built-in electric field promote charge transfer at the heterojunction interface more effectively. The synergistic mechanism of the facet junction and p-n junction finally achieves high-efficiency hydrogen production. This work provides new insights into how to construct efficient p-n heterojunction photocatalysts and presents the synergistic mechanism of facet junction and p-n junction.
研究领域:
材料科学
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能源科学
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化学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Qi Wang,Chenlu Zhang,Hong Wu,Qiaoyuan Gao,Ran Duan,Chuncheng Chen
Bi 2 O 2 CO 3 was co-decorated by β-phase AgI and Bi 2 O 3 forming visible-light-active AgI(β)/Bi 2 O 3 (β)-Bi 2 O 2 CO 3 composite via simply calcining AgI/Bi 2 O 2 CO 3 . The calcination temperature and time played vital role in regulating the structure as well as photocatalytic performance. Optimal AgI(β)/Bi 2 O 3 (β)-Bi 2 O 2 CO 3 was obtained after 325 ◦ C calcination for 2 h with 5% AgI. The ratio of Bi 2 O 3 to Bi 2 O 2 CO 3 was estimated to be ca. 3:1 on the catalyst surface. The transformation process for n -type Bi 2 O 2 CO 3 to p-type Bi 2 O 3 (β) was monitored and verified by flat band potential measurements. Due to the presence of p-n junctions between p-type Bi 2 O 3 (β), n -type AgI(β) and Bi 2 O 2 CO 3 , the optimized ternary composite displayed enhanced photocurrent density and reduced charge transfer resistance, which were beneficial for photocatalytic applications. Despite of decreased specific surface area, dramatically enhanced photocatalytic performance can be observed for simultaneous removal of Cr(VI) and phenol . For example, the estimated k Cr(VI) and k phenol on AgI(β)/Bi 2 O 3 (β)-Bi 2 O 2 CO 3 were 3.3 and 2.2 times relative to those on uncalcined AgI/Bi 2 O 2 CO 3 , respectively. The optimized composite also displayed good stability in 4 successive cyclic runs.
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Advanced Electronic Materials
·
2018
·Vol. 4
·期 11
·1800237
·
IF 5.466
Xin Wang,Yao Wu,Guanwen Li,Jun Wu,XiaoBing Zhang,Qing Li,Baoping Wang,Jing Chen,Wei Lei
Organometallic perovskites are candidates for low-dose ionizing radiation due to their large mobility-lifetime product, large radiation absorption coefficient, high stability at ambient temperature, and ability to crystallize from solution at low temperatures. However, multiple unstable and expansive organic layers are required to block injected charges from the applied voltage. Here, a radiation photodiode based on p–n junctions formed in the CH 3 NH 3 PbI 3 crystallization process without any other organic layers is reported. Through controlling the location of the dopant, selenium (Se), and its concentration inside CH 3 NH 3 PbI 3 single crystals, the valence band offset of the band alignment is measured as 0 to 0.45 eV. The photodiodes require only two gold electrodes deposited on opposite faces of the CH 3 NH 3 PbI 3 single crystals, and the sensitivity for 60 keV X-ray and 1.25 MeV gamma-ray from Cobalt-60 reached 21 µC mGy air cm −2 and 41 µC Gy air cm −2 , respectively. Experiments measured the ultrafast response time to be 3 µs.
研究领域:
材料科学
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辐射物理学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
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2019
·
IF 7.65
Yan Sang,Xi Cao,Guangdong Dai,Lvxuan Wang,Yin Peng,Baoyou Geng
The construction of heterojunction system can promote the separation and transfer of photogenerated electron-hole pairs, which is conducive to the degradation of sewage. In this paper, heterostructured Bi 2 O 3 /Bi 2 S 3 nanoflowers are fabricated by a one-step hydrothermal method. The microstructure and optical absorption properties are studied through the detailed characterization of this heterojunction. The visible light photocatalytic ability of as-prepared Bi 2 O 3 /Bi 2 S 3 heterojunctions are investigated by photocatalytic removals of RhB and Cr(VI). The results of photocatalysis indicate that removal efficiencies of RhB and Cr(VI) over Bi 2 O 3 /Bi 2 S 3 heterojunction are higher than those of pure Bi 2 O 3 and Bi 2 S 3 . The improved photocatalytic performance of the Bi 2 O 3 /Bi 2 S 3 heterojunctions could be attributed to a combination of the p-n junction between the p-type Bi 2 S 3 and n-type Bi 2 O 3 , and large specific surface areas (46.31 m 2 g −1 ). Moreover, the probable photocatalytic mechanism of composite photocatalysts is explored in detail by active species trapping experiments, N 2 adsorption–desorption, the transient photovoltage electrochemical impedance spectroscopy and photoluminescence measurements. This work provides new insights into building of the efficient and novel heterogeneous photocatalysts and other energy-related devices.
研究领域:
材料科学
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环境科学
✓ 已验证
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2016
·
IF 4.758
Sisi Fan,Minggang Zhao,Longjiang Ding,Ye Ma,Jingjing Liang,Xingtao Wang,Yawen Song,Shougang Chen
Eggshell membranes were used as biotemplate to fabricate a 3D hierarchical porous Co 3 O 4 /ZnO p-n junction film. Multiple catalysis and accelerated electron transfer were achieved on the Co 3 O 4 /ZnO-GOx electrode by introducing the p-n junction interface into enzyme loading matrix. A stable and well-defined oxidation peak of glucose was obtained with a largely decreased detection potential of 0.25 V. Furthermore, an enhanced sensitivity (116.64 μA·mM −1 ·cm −2 ) was also achieved comparing with the simple biotemplate-synthesized Co 3 O 4 and ZnO film. The results demonstrated it is a novel strategy to improve the biosensing performance by introducing p-n junction interface into enzyme loading matrix.
研究领域:
生物化学
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材料科学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2020
·Vol. 44
·期 8
·3194-3205
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IF 3.288
Jiabin Liu,Bowen Yang,Minghuan Gao,Lisha You,Yuansen Zhang,Zhiying Li,Linna Guo,Tiesheng Li,Penglei Chen,Minghua Liu
A series of novel efficient polyhedron-like WO3/butterfly-like Ag2MoO4 p–n junction photocatalysts (denoted as AMW-x) were designed and synthesized. The exact phase structure, microscopic morphology, electrochemical properties, physical properties and optical properties of the prepared samples were characterized by XRD, SEM, EDS, TEM, HRTEM, UV-DRS, PL, FL, XPS, UPS, BET, MS (Mott–Schottky test), EIS and photocurrent measurements. The photocatalyst could effectively degrade rhodamine B (RhB) under UV/Solar region light illumination. In this system, a p–n junction structure formed by the two different materials effectively enhanced the generation rate of photo-induced electrons and reduced the transfer resistance. These results exhibited that enhanced photocatalytic performance of materials were prepared. The activity of AMW-20 was 548.2/496.8, 57.9/146.1, and 3.7/17 times higher than polyhedron-like WO3, butterfly-like Ag2MoO4, and commercial powder (P25) under UV/Solar region light illumination. The photocatalytic mechanism mode for the improved photocatalytic performance was also proposed.
研究领域:
材料科学
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环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2022
·
IF 6.796
Yong Wang,Cheng Liu,Haoyun Hu,Qiujun Lu,Haiyan Wang,Chenxi Zhao,Fuyou Du,Ningli Tang
The construction and application of novel highly efficient photocatalysts have been the focus in the field of environmental pollutant removal . In this work, a novel CuFe 2 O 4 /Bi 12 O 17 Cl 2 photocatalysts were synthesized by simple hydrothermal and chemical precipitation method. The fabricated CuFe 2 O 4 /Bi 12 O 17 Cl 2 composite exhibited much higher photocatalytic activity than pristine CuFe 2 O 4 and Bi 12 O 17 Cl 2 in the removal of bisphenol A (BPA) under visible-light illumination, which ascribed to the intrinsic p-n junction of CuFe 2 O 4 and Bi 12 O 17 Cl 2 . The photocatalytic degradation rate of BPA on CuFe 2 O 4 /Bi 12 O 17 Cl 2 with an optimized CuFe 2 O 4 content (1.0 wt.%) reached 93.0% within 30 min. The capture experiments of active species confirmed that the hydroxyl radicals (•OH) and superoxide radicals (•O 2 − ) played crucial roles in photocatalytic BPA degradation process. Furthermore, the possible degradation mechanism and pathways of BPA was proposed according to the detected intermediates in photocatalytic reaction process.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2024
·
IF 5.3
Zhouzhou Li,Zheng Li,Feng He,Wen He,Qixu Chen,Hongqing Wang
Recently, how to improve the photocatalytic uranium removal performance of Graphite-phase carbon nitride (GCN) has always been a hot research topic. In this paper, a new strategy based on p-n junction and D-A structure is proposed to improve the photocatalytic performance. And as a result, a novel cyano modified photocatalytic material NC-GCN/Ag 2 O was designed and prepared for the reduction of U(VI). Interestingly, the material shows better adsorption performance for U(VI) in the dark treatment stage, and its removal of U(VI) is close to 70 % under the initial U(VI) concentration of 20 ppm and the solid–liquid ratio of 0.2 g/L. And the adsorption is in accordance with the Langmuir model and Pseudo second order model. After 30 min of illumination, the removal rate of U(VI) can reach 93.2 %, significantly higher than that of GCN (13.6 %) and NC-GCN 10 (37.7 %). It’s worth mentioning that photocatalytic reduction dominated the adsorption-reduction process for U(VI) removal after light exposure. In addition, after four cycles, the removal of U(VI) from the composite material decreased by only 5 % with no change in the crystal structure, i.e., it has good reusability and stability. Meanwhile, there was no significant interference with other ions except for Cu 2+ and V 5+ , which had a weak interference. Finally, a new mechanism for U(Ⅵ) reduction was proposed.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2019
·
IF 3.261
Minghuan Gao,Lisha You,Linna Guo,Tiesheng Li
Polyhedron-like WO 3 (n-type WO 3 ) nanoparticles were synthesized by a simple hydrothermal reaction without using any template or surfactant. The Polyhedron-like WO 3 /Ag 2 CO 3 p-n junction photocatalyst was first synthesized by a simple impregnation-deposition way. The obtained samples were investigated by XRD, BET, XPS, SEM, TEM etc. The separation mechanisms of photo-induced electrons (e − ) and photo-induced holes (h + ) of the Polyhedron-like WO 3 /Ag 2 CO 3 p-n junction samples were characterized by PL technique, EIS and determination of active sites and species in the photocatalytic reactions. In this p-n junction structure, Polyhedron-like WO 3 nanoparticles adhered to the surface of the Rod-like p-type Ag 2 CO 3 nanoparticles. The Polyhedron-like WO 3 /Ag 2 CO 3 p-n junction photocatalyst showed much higher photocatalytic activity than both single materials for RhB degradation under UV–vis light irradiation, and even 17 times higher than commercial powders (P25) at the same circumstance. Even compared with the related photocatalyst, it still exhibits the highest photocatalytic ability. The highly enhanced photocatalytic of the Polyhedron-like WO 3 /Ag 2 CO 3 p-n junction photocatalyst can be attributed to extended absorption, more effective separation of photogenerated charges, the transfer rate of photo-induced charge carriers and forming of p-n junction system.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2020
·Vol. 8
·期 7
·4083-4090
·
IF 11.301
Jin Liu,Xingcai Zhang,Qian Zhong,Jun Li,Hongzhang Wu,Bo Zhang,Lin Jin,Hua Bing Tao,Bin Liu
Semiconductor p–n junction engineering plays an indispensable role in developing highly efficient photocatalysts for energy conversion and environmental remediation. Herein, a novel AgI/Bi2Ga4O9 p–n junction photocatalyst is successfully constructed by an electrostatic self-assembly approach. Photoelectrochemical characterization together with density functional theory calculations shows that the formation of a p–n junction at the AgI/Bi2Ga4O9 interface favors separation and transfer of photogenerated charge carriers. The ˙O2− generated by 25%-AgI/Bi2Ga4O9 reaches a concentration of 18.8 μmol L−1 after 60 min of irradiation, which is 3.3 and 12.5 times higher than that generated by AgI and Bi2Ga4O9, providing 25%-AgI/Bi2Ga4O9 with greatly enhanced photocatalytic activity toward Acid Red 1 and metronidazole degradation. Our work provides a novel strategy for designing highly efficient photocatalysts for a wide range of energy and environmental applications.
研究领域:
材料科学
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环境科学
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能源科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Shuhui Liang,Manman He,Jingjing Guo,Jie Yue,Xipeng Pu,Bo Ge,Wenzhi Li
The BiOBr:Yb 3+ ,Er 3+ /g-C 3 N 4 (BYE/CN) p-n junction photocatalysts were successfully fabricated by a stepwise method. Experimental results show that Er 3+ /Yb 3+ were successfully doped into BiOBr lattice. As-obtained BYE/CN exhibited strong NIR light absorption and upconversion emission from NIR to UV–visible due to the upconversion transition of Er 3+ . The p-n junction was constructed due to the appropriate alignment band structure of BYE and g-C 3 N 4 , which distinctly suppresses the recombination rate of electron-hole pairs. Compared with pure BYE and CN, as-synthesized BYE/CN samples exhibit distinctly improved photoactivities under the irradiation of visible or NIR light, which can be attributed to the upconversion effect of Er 3+ and the construction of p-n junction. This result may provides a promising system for efficient harvest of the NIR light, which will contribute to the utilization of solar energy in the future.
研究领域:
材料科学
·
光催化
·
能源利用
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）