Surfaces and Interfaces
·
2024
·
IF 5.7
Zhonghui Han,Xiaobin Yang,Xinnan Shi,Leyao Wu,Peng Hu,Haibo Fan,Feng Teng
The band structure of heterojunction plays an important role in the performance of actual application and can be adjusted by the change of preparation condition. Herein, Cu 2 O nanofilms with different band structures were prepared via electrodeposition method by modifying the solution environment. With the value of pH increased from 7 to 12, the conductivity of the Cu₂O nanofilms shifted from n-type to p-type. Combined the obtained Cu 2 O film with TiO 2 nanoarray, the Cu 2 O/TiO 2 heterojunction were prepared. The photoelectrochemical performance of the Cu 2 O/TiO 2 heterojunction was affected by the interfacial band structure. The T7 sample has higher photocurrent (450 μA) caused by the unique S-scheme band structure, the T11 sample with a p-n junction structure takes second place (225 μA). The n-n type II heterojunction has the lowest photocurrent (20 μA). The Fermi level of Cu 2 O nanofilm was affected by the type of defects, such as oxygen and copper vacancies, leading to changes of band structure at the interface between Cu 2 O and TiO 2 . The obtained result further illustrates the importance of energy band engineering, and provides route and sight for the development and application of Cu 2 O/TiO 2 heterojunction.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Small
·
2024
·
IF 13
Aizhu Chen,Xuhui Yang,Lijuan Shen,Ying Zheng,Min-Quan Yang
Loading cocatalysts onto semiconductors is one of the most popular strategies to inhibit charge recombination, but the efficiency is generally hindered by the localized built-in electric field and the weakly connected interface. Here, this work designs and synthesizes a 1D P-doped CdS nanowire/Ni 2 P heterojunction with gradient doped P to address the challenges. In the composite, the gradient P doping not only creates a funneled bandgap structure with a built-in electric field oriented from the bulk of P-CdS to the surface, but also facilitates the formation of a tightly connected interface using the co-shared P element. Consequently, the photogenerated charge carriers are enabled to be pumped from inside to surface of the P-CdS and then smoothly across the interface to the Ni 2 P. The as-obtained P-CdS/Ni 2 P displays high visible-light-driven H 2 evolution rate of ≈8265 µmol g −1 h −1 , which is 336 times and 120 times as that of CdS and P-CdS, respectively. This work is anticipated to inspire more research attention for designing new gradient-doped semiconductor/cocatalyst heterojunction photocatalysts with bridged interface for efficient solar energy conversion.
研究领域:
材料科学
·
能源转换
·
光催化技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2021
·Vol. 11
·期 11
·2940
·
IF 5.076
Bingke Zhang,Shengwen Fu,Dongbo Wang,Shujie Jiao,Zhi Zeng,Xiangyu Zhang,Zhikun Xu,Yaxin Liu,Chenchen Zhao,Jingwen Pan,Donghao Liu,Jinzhong Wang
The photocatalysis technique has been proven to be a promising method to solve environmental pollution in situations of energy shortage, and has been intensively investigated in the field of pollutant degradation. In this work, a band structure-controlled solid solution of BiOBrXI1−X(x = 0.00, 0.05, 0.10, 0.15, 0.20, 1.00) with highly efficient light-driven photocatalytic activities was successfully synthesized via simple solvothermal methods. The phase composition, crystal structure, morphology, internal molecular vibration, optical properties, and energy band structure were characterized and analyzed by XRD, SEM, HRTEM, XPS, Raman, and UV Vis DRS. To evaluate the photocatalytic activity of BiOBrXI1−X, rhodamine B was selected as an organic pollutant. In particular, BiOBr0.15I0.85displayed significantly enhanced photocatalytic activity by virtue of modulating the energy band position, optimizing redox potentials, and accelerating carrier separation. Moreover, the enhancement mechanism was elucidated on the basis of band structure engineering, which provides ideas for the design of highly active photocatalysts for practical application in the fields of environmental issues and energy conservation.Keywords:BiOBrXI1−X;solid solution;photocatalytic degradation;band structure engineering
研究领域:
环境科学
·
材料科学
·
化学
✓ 已验证
DOI
PubMed
高影响因子
Applied Materials Today
·
2022
·
IF 8.663
Wei Jiao,Lili Zhang,Ruiquan Yang,Jing Ning,Lei Xiao,Yifan Liu,Jianyi Ma,Nasir Mahmood,Xian Jian
Increasing visible light absorption and constructing an active surface for TiO 2 have long been pursued to obtain high photocatalytic activities. Modifying TiO 2 at an atomic scale is desirable to optimize its surface state and band structure but remains a huge challenge. Herein, we developed an ultrasmall (∼5 nm) visible-light-responsive TiO 2 photocatalyst with a novel hybrid structure (TiO 2 /C) through a chemical vapor deposition process on large scale. Environmental in-situ transmission electron microscope studies confirmed the anatase TiO 2 with a monolayer carbon shell in a hybrid structure. The resulted structure possesses narrowed bandgap 2.83 eV, favoring the enhanced visible-light-responsive photocatalytic activity. Density functional theory (DFT) simulations confirm the tunable mechanism of carbon-induced localized energy band within the bandgap of TiO 2 . As a physical barrier without turning TiO 2 black, the monolayer carbon shell stabilizes Ti 3+ inside TiO 2, facilitates the separation of photo-induced carriers and enriches abundant absorbing sites of target pollutants. Consequently, the TiO 2 /C exhibits outstanding photocatalytic performance in both photoelectrochemical water oxidation and dye degradation under visible light besides superior activity for hydrogen evolution under simulated sunlight irradiation. This design proved a meaningful strategy in obtaining visible-light-responsive photocatalysts with a stable active surface for industrial application.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2014
·
IF 3.552
Yaru Ni,Wei Wang,Wenjuan Huang,Chunhua Lu,Zhongzi Xu
A new idea was employed to simultaneously reduce graphene oxide (GO) and wrap it on the surface of high-reactive anatase TiO 2 for fabricating novel TiO 2 -graphene (GP) hybrid materials. The process was based on the surface negatively charged property of GO. With the introduction of strong chemical interaction between TiO 2 and GP, the GP wrapped TiO 2 gives a strong red-shift of the light absorption edge and a further narrowed bandgap compared to that of GP randomly supported TiO 2 . This structure can also significantly enhance the separation efficiency of photogenerated electrons and holes. Furthermore, in contrast to the normal anatase TiO 2 , as-prepared TiO 2 is dominated with the high-reactive {0 0 1} facet. The superiority of the formed “core–shell” structure is confirmed by photocatalytic degradation of methylene blue (MB) under the xenon lamp and visible light irradiation. New photocatalytic mechanisms are also proposed based on the obtained results. This work may open a new doorway for new significant application of GP to prepare more GP-based high-reactive photocatalysts for environmental protection.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Peijie Ma,Xu Zhang,Cong Wang,Zhiwei Wang,Kaiwen Wang,Yibo Feng,Jiaxing Wang,Yadi Zhai,Jiguang Deng,Lihua Wang,Kun Zheng
Polymeric carbon nitride (C 3 N 4 ) is a very attractive candidate to produce photocatalytic hydrogen peroxide (H 2 O 2 ) due to its low-cost, metal-free characteristics. However, the low efficiency would limit its development to higher yields because of insufficient light absorption and electron-hole separation. Here, we developed a simple method to anchor CN quantum dots (QDs) onto g-C 3 N 4 nanosheets to form a homojunction structure (HJ-C 3 N 4 ), which could improve photocatalytic performance largely without introducing metal elements. Its superior efficiency is a result of the band alignment by the homojunction structure providing excellent electron-hole separation and QDs providing suppressed recombination. Simultaneously, the light responsiveness of QDs endows a wide spectrum-responsive adsorption and enhances the adsorption intensity. The H 2 O 2 yield of the HJ-C 3 N 4 reached 115 μmol L −1 h −1 in pure water by visible light, which has an 8.6x higher production than g-C 3 N 4 nanosheets . The material design of 0D/2D homojunction could be extended to other materials with specific band alignment.
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
OPTICAL MATERIALS
·
2021
·
IF 3.08
Tingting Li,Chengcheng Sun,Chang Xue,Yutao Jiang,Jian Zhang,Lijuan Zhao
Iron (Fe) doped ZnSe microspheres were fabricated by solvothermal method . X-ray diffraction (XRD), Raman analysis, Fourier transform infrared (FT-IR) spectra and X-ray photoelectron spectroscopy (XPS) results indicate that Fe 2+ cations were incorporated into the zinc blende ZnSe lattices successfully and uniformly distributed in sample. SEM images displayed that doping with Fe 2+ cations did not change the morphology of microspheres . The growth mechanism of Fe-doped ZnSe microspheres was proposed. The band gap increases and photoluminescence (PL) peaks in visible region show blue-shift as doping with Fe ions . In addition, a reduction in PL lifetimes in visible range was also observed, which may be due to the increase in non-radiative energy transfer between Fe 2+ doping in the ZnSe matrix. The 5 E↔ 5 T 2 transition of Fe 2+ in the 3.6–5.5 μm spectral range was observed in Fe-doped sample at low temperature.
研究领域:
材料科学
·
光学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2024
·
IF 10.7
Zhengjie Su,Xinru Wu,Dong-Hau Kuo,Baoqian Yang,Binghong Wu,Longyan Chen,Pengkun Zhang,Jinguo Lin,Dongfang Lu,Xiaoyun Chen
Herein, an Ag/S co-doped Bi2O3-based sulfur oxide catalyst was prepared via a facile green method. The Ag/S–Bi2O3 catalyst with suitable Ag/S doping demonstrated super visible light photocatalytic hydrogen evolution (PHE) at 7.52 mmol g−1 h−1, with an apparent quantum efficiency (AQE) of 8.67% at 420 nm. Ag/S co-doping can adjust the energy band structure of an oxidation type Bi2O3 catalyst, converting it into a visible light hydrogen production catalyst suitable for hydrogen production. Sulfur doping adjusts the content of oxygen vacancies to enhance the surface active sites, and the introduction of noble metal silver endows the catalyst with more excellent electrical conductivity and electron trapping ability. Thus, Bi2O3 with Ag/S co-doping produced a suitable energy band structure, enhanced the content of oxygen vacancies and the number of surface active sites, and endowed the catalyst with excellent electrical conductivity and electron trapping ability, significantly producing catalysts with excellent visible light PHE activity. Furthermore, Ag/S–Bi2O3-3 exhibited super visible light PHE activity and excellent stability and persistence and is expected to play a potential role in the field of PHE reactions (PHERs).
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2023
·
IF 6.7
Wei Wang,Qinyang Sheng,Guowei Zhi,Yuan Zhao,Ruiyang Qu,Luanhong Sun,Shengli Zhang
Photocatalytic technology based on heterojunction structure has been proved to be an effective way to solve environmental pollution and energy crisis. The effective carrier concentration plays an important role in improving the performance of heterojunction photocatalyst. In this work, CuSbS 2 (CAS)-CdS-ZnO was prepared by simple 3-steps microwave irradiation method to reveal the influence of energy band structure on photocatalytic performance. Adding CdS could regulate band alignment to translate the “cliff-like” conduction band offset of CAS-ZnO to “spike-like”. That could effectively reduce the carrier recombination rate to improve the photocatalytic degradation activity, which could completely degraded Rhodamine B (RhB) after 80 min under a solar simulation, highest rate constant (0.02028 min −1 ) and good stability. Furthermore, the transformation of charge transfer mechanism from the Z-type to Ⅱ-type by adding CdS were confirmed by experiments and density functional theory (DFT) calculations. This change could raise the energy level of photoelectrons, resulting in CAS-CdS-ZnO with a certain photocatalytic hydrogen evolution capacity (42.37 μmol g −1 h −1 ). This work reveals the important role of band structure in photocatalytic properties and applications of heterojunction.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Electronic Materials
·
2024
·
IF 4.3
Mengchen Zhou,Yang Ma,Jingtao Li,Xiaoting Wang,Hu Chen,Zhimin Xiong,Yan Zhou,Jialin Liu,Xiaoqing Chen,Yongzhe Zhang
Polarization photodetection has attracted much attention as a promising method to get more information from the target objects, and in this field, two-dimensional (2D) materials with a low-symmetric structure show great potential for their ability to distinguish light with different polarization direction. However, limited by the intrinsic crystal structure and forbidden bandwidth of such materials, there are hindrances in optimizing polarization photodetection performance, such as improving the anisotropic current ratio as well as expanding the detection spectral range. Even though low-symmetric materials have been stacked through mechanical transfer as a possible solution, the varying relative angles between different materials and the pollution at the interface induced during the transfer process still have negative effects on the photodetection performance of these heterojunctions. In order to solve the mentioned problems, a strategy to form highly low-symmetry GeSe2–GeSe heterojunctions by selenization of single GeSe crystals has been proposed, for which the b-axis direction of GeSe2 and the armchair direction of GeSe are spontaneously in parallel. The synthesized heterojunctions with type-II energy band arrangement can reach an anisotropic current ratio up to 3.5 (at 808 nm) and exhibit a higher absorption compared to single GeSe. This work presents a scheme for preparing low-symmetry heterojunctions by in situ transformation, which suggests a potential approach for optimizing linearly polarized photodetectors based on the designed heterojunctions’ growth.
研究领域:
材料科学
·
光学工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2019
·
IF 4.084
Xing-Liang Yin,Lei-Lei Li,Da-Cheng Li,Zhong-Jia Li,Yuan-Xu Wang,Xiang-Jin Kong,Jin-Sheng Zhao,Jian-Hua Jiang,Jun-Chao Qian,Dong-Hui Pang,Xin-Xin Du,Jian-Min Dou
Photocatalytic water splitting is considered to be a green H 2 generation approach and has potential to be applied in the future. As a photocatalytic active material for H 2 evolution, CdS is a good candidate. However, the pristine CdS still suffers from low efficiency and poor stability. To address those issues, we developed noble-metal-free CdS@MoS 2 core-shell nanoheterostructures which exhibit outstanding photocatalytic H 2 evolution performance thus far with rate of 62.55 mmol g −1 h −1 , which exceeds that of pristine CdS by a factor of 148. Meanwhile, the photocatalytic stability can be well retained with no deterioration of activity in 24 h reaction. The excellent performance can be reasonably attributed to the low crystallinity of MoS 2 with numerous active sites provided, and the band alignment of CdS and MoS 2 as determined by valence band-XPS and Mott-Schottky plots analysis, which significantly promotes charge transportation and separation. The enhanced photocatalytic stability here should be ascribed to the intimate growth of MoS 2 shells which significantly passivate the surface trap states of CdS cores and thus the photocorrosion is remarkably retarded. This novel strategy will inspire the fabrication of other photocatalytic systems, and may high-efficient photocatalysts be obtained.
研究领域:
材料科学
·
能源化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Xiaobo Bai,Chengyan Liu,Fucong Li,Zhongwei Zhang,Ying Peng,Ruifan Si,Baoquan Feng,Guojing Wu,Jie Gao,Haiqiao Wei,Lei Miao
Lead-free GeTe-based thermoelectric (TE) materials are most promising candidates to replace the environmentally harmful PbTe for TE application at middle temperature range, where high power factor ( PF ) is significantly important for high power generation if the cost of heat source is low enough. In this study, we report for the first time that the PF of GeTe can be greatly enhanced by tailoring the interaction between Te 5s 2 lone pair and antibonding orbitals, which is induced by the hybridization of Zr 4d 2 electrons with antibonding orbitals. As a result, the contribution of Ge 4s 2 electrons to the valence band is promoted, leading to the band sharpening at the valence band maximum in rhombohedral phase, and simultaneous band sharpening at the valence band maximum and band flattening at the conduction band minimum in cubic phase. Lower band effective mass m b * effectively increases the carrier mobility to a very high value of ∼121 cm −2 V −1 s −1 (300 K), and the Seebeck coefficient is improved by the reduced detrimental effect of minority carrier in cubic phase, enhancing the maximum PF up to a record value of ∼5503 μW m −1 K −1 . With the assistance of reduced thermal conductivity, a peak zT of ∼1.9 is achieved at 673 K, which is one of the highest values among single doped GeTe. This work provides a new guidance to enhance the TE performance of GeTe-based materials.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）