Nanoscale
·
2020
·Vol. 12
·期 20
·11267-11279
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IF 6.895
Hongkai Zhao,Xiaoxia Li,Mingyue Zheng,Xian Zhao,Qun Zhang,Yi Luo,Weiliu Fan
The construction of both highly efficient and stable hybrid artificial photosynthetic systems comprising semiconductors as photosensitizers and abundant metal-based molecular complexes as cocatalysts for photocatalytic H2 generation remains challenging. Herein, we report an effective and stable CdS/cobaloxime hybrid system prepared by inserting an amorphous TiO2 (a-TiO2) interlayer with adjustable thickness and by covalently-surface-attaching molecular cobaloxime catalysts. This hybrid system displayed outstanding photocatalytic H2 production and reached a maximum rate of ∼25 mmol g−1 h−1, which was ∼20.8 times that of pure CdS and 1.7 times that of the CdS/cobaloxime system without an a-TiO2 interlayer (CdS/Co). More importantly, 6 nm a-TiO2 uniformly coated CdS nanorods (CdS NRs) exhibited exceptional 200 h long-term catalytic behaviour under ≥420 nm visible light irradiation. However, the H2 production performance of the CdS/Co hybrid system decreased significantly over 10 h. Density functional theory (DFT) calculations indicated that the a-TiO2 surface can provide abundant bonding sites for the effective immobilization of molecular catalysts. Moreover, Mott–Schottky electrochemical measurements and femtosecond transient absorption spectroscopy revealed that the a-TiO2 interlayer had favourable band levels that could fasten the photoexcited electron transfer from CdS to molecular cobaloxime and could extract holes with intraband electronic states generated by defects, thus prohibiting CdS photocorrosion and improving the stability of the hybrid system. This study proposes a strategy for designing multifunctional interlayers for the effective immobilization of molecular catalysts, beneficial regulation of photoinduced charge carriers, and improvement of the stability as well as facilitation of the construction of artificial photosynthetic hybrid systems with high efficiency and durability.
研究领域:
材料科学
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光化学
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能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Advanced Materials Interfaces
·
2018
·Vol. 5
·期 22
·1801015
·
IF 4.834
Yang-Fan Xu,Xu-Dong Wang,Jin-Feng Liao,Bai-Xue Chen,Hong-Yan Chen,Dai-Bin Kuang
Artificially photocatalytic reduction of CO 2 into valuable chemicals, responding to the call of carbon neutral economy, has aroused considerable interests so far. Among those photocatalysts screened, an emerging and promising alternative of inorganic CsPbBr 3 perovskite has recently been reported. Here, to attain preferable photocatalytic performance, an amorphous-TiO 2 -encapsulated CsPbBr 3 nanocrystal (CsPbBr 3 NC/a-TiO 2 ) hybrid is demonstrated through a solution processing strategy. After optimizing the a-TiO 2 matrix amount by tuning the tetrabutyl titanate precursor volume, the CsPbBr 3 NC/a-TiO 2 composite exhibits a marvelous 6.5-fold improvement on the consumption of photoelectrons in photocatalytic CO 2 reduction reaction when compared with the individual CsPbBr 3 NC. Such significant enhancement is ascribed to the accelerated electron–hole separation and the multiplied CO 2 adsorption. Thus, as an available prototype, this work offers a rational encapsulation design for efficient halide perovskite photocatalyst.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Materials Research Express
·
2018
·Vol. 5
·期 4
·045051
·
IF 1.151
Shuai Mao,Rui Bao,Dong Fang,Jianhong Yi
Amorphous-TiO2/Cu2Cl(OH)3 (am-TiO2/Cu2Cl(OH)3) composite photocatalyst was synthesized by a facile and novel spray pyrolysis method. The morphology, crystal structure, chemical composition, optical properties, and photocatalytic activity of the composite were characterized and investigated. It was noted that heating temperature played a fundamental role in determining the morphology of the composite photocatalyst as well as the crystallinity of TiO2. Am-TiO2 was firmly anchored on Cu2Cl(OH)3 with well dispersibility and served as the main sunlight absorber. Meanwhile, Cu2Cl(OH)3 acted as not only a carrier, but also a chemical catalyst of H2O2 to produce O2 (electron acceptor). Compared with commercially available P25 specie, the composite with the addition of H2O2 exhibited higher photocatalytic performances for methyl orange (MO) degradation under simulated solar light irradiation. By considering the mechanism, the excellent performance was awarded to uniform dispersion of am-TiO2 in the unique Cu2Cl(OH)3 and superfluous electron acceptor.
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
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 27
·16541-16552
·
IF 10.733
Xuefang Xie,Yang Hu,Guozhao Fang,Xinxin Cao,Bo Yin,Yaping Wang,Shuquan Liang,Guozhong Cao,Anqiang Pan
As a promising conversion-type anode material, iron sulfide has been widely studied. However, due to its huge volume expansion during repeated lithiation/delithiation, iron sulfide tends to pulverize and form aggregates upon cycling, which greatly hinders its application in high performance lithium ion batteries as a durable anode material. Herein, a strategy for synthesizing and stabilizing iron sulfide nanosheets with a robust titanium oxide nanofiber interior support is proposed. The hierarchical nanostructured composite anode material was successfully synthesized by the electrospinning technique and subsequent sulfurization. The size of the iron sulfide nanosheets can be easily tuned by adjusting the composition of the reacting agents and/or the sulfurization temperature. Electrochemical results reveal that the composite delivers a reversible capacity of 591 mA h g−1 at a current density of 0.1 A g−1 after 100 cycles and exhibits excellent long-term cycling stability at 0.5 A g−1 and 1 A g−1 as well. Furthermore, when being paired with LiFePO4, the as-synthesized composite also delivers promising full-cell performance, showing its potential in serving as a competitive candidate anode material in lithium-ion batteries for power applications. Moreover, this method also opens up an avenue for modifying and improving other conversion-type anode materials.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Minji Yang,Huichao He,Hongping Zhang,Xiaohui Zhong,Faqin Dong,Gaili Ke,Yaqi Chen,Jinyan Du,Yong Zhou
High surface states induced photoelectrochemical (PEC) activity and stability issue is the major performance bottleneck for nanostructured WO 3 photoanode. Here we report that amorphous TiO 2 ( α -TiO 2 ) be used as passivator to modify the surface states of WO 3 nanoflakes film for improving its PEC water oxidation performance. In comparison with bare WO 3 film, the α -TiO 2 -coupled WO 3 ( α -TiO 2 /WO 3 ) film is of higher PEC water oxidation activity and stability. The photocurrent on α -TiO 2 /WO 3 film photoanode is improved by 2 times that reached 1.4 mA/cm 2 in 0.1 M Na 2 SO 4 solution at 0.8 V ( vs. SCE). After α -TiO 2 coupling, the UV–vis absorption edge and intensity of WO 3 film do not change obviously, but the formation and oxidation kinetics of H 2 O 2 on WO 3 photoanode are modified. The density functional theory calculations indicate the monoclinic WO 3 (002) has a surface energy of 1.17 J/m 2 , whereas the α -TiO 2 /WO 3 (002) with a much lower surface energy of 0.3 J/m 2 . Additionally, the length of Ti O bond of α -TiO 2 is changed from the initial 1.929 Å to a shorter length of 1.886 Å and a longer length of 2.290 Å in α -TiO 2 /WO 3 (002) through the O 2- -W 6+ bonding effect at α -TiO 2 /WO 3 interface. Therefore, the enhanced PEC water oxidation performance on α -TiO 2 /WO 3 film can be attributed to that α -TiO 2 passivates the surface states of WO 3 nanoflakes film, and the formation of H 2 O 2 from the photoexcited-electrons/dissolved-oxygen route is depressed and the PEC oxidation of H 2 O 2 is accelerated.
研究领域:
材料科学
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能源化学
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计算化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2017
·
IF 3.387
Yang Zhang,Xintong Zhang,Dan Wang,Fangxu Wan,Yichun Liu
Introducing appropriate amount of oxygen vacancies by hydrogenation treatment is a simple and efficient way to improve the photoelectrochemical performance of nanostructured oxide photoanodes. However, the hydrogenation effect is often not durable due to the gradual healing of oxygen vacancies at or close to surface of photoanodes. Herein, we tackled the problem by conformal coating the hydrogenated nanoporous BiVO 4 (H-BiVO 4 ) photoanode with an ultrathin layer of amorphous TiO 2 . Photoelectrochemical measurements showed that a 4 nm-thick TiO 2 layer could significantly improve the stability of H-BiVO 4 photoanode for repeated working test, with negligible influence on the initial photocurrent compared to the uncoated one. Mott–Schottky and linear sweep voltammetry measurements showed that donor density and photocurrent density of the H-BiVO 4 electrode almost decayed to the values of pristine BiVO 4 electrode after 3 h test, while the amorphous TiO 2 -coated electrode only degraded by 6% and 5% of the initial values respectively in the same period. The investigation thus suggested that the amorphous TiO 2 layer did protect the oxygen vacancies in H-BiVO 4 photoanode by isolating these oxygen vacancies from environmental oxygen, while at the same time not impeding the interfacial charge transfer to water molecules due to its leaky nature.
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
JOURNAL OF NON-CRYSTALLINE SOLIDS
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2022
·
IF 4.458
Li Gao,Dujiang Lu,Yinghui Yang,Rongzhang Guan,Dongmei Zhang,Chenyi Sun,Shuai Liu,Xiufang Bian
A simple synthesis has been proposed for seaweed-like amorphous TiO 2-x modified Sb (a-TiO 2-x /Sb) composite nanowires as sodium-ion battery (SIBs) anodes by a dealloying method of Al-Sb-Ti alloys. Compared with other conventional methods, this method has the advantages of simple preparation, high yield and easy large-scale synthesis. It is excitingly discovered that a-TiO 2-x /Sb effectively alleviates volume changes and stabilizes the solid electrolyte interface (SEI). The a-TiO 2-x /Sb nanowires electrodes deliver outstanding electrochemical performance based on the synergistic effects, exhibiting a high reversible capacity of 591.9 mA h g −1 at 100 mA g −1 , stable cycling performance with a high capacity retention of 96.4% after 200 cycles and superior rate capability 382.2 mA h g −1 at 10,000 mA g −1 , which is very competitive among the reported Sb-based anodes.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2020
·
IF 8.758
Bowen Ren,Qiuyan Jin,Yinwei Li,Yan Li,Hao Cui,Chengxin Wang
Though transition-metal-based materials have emerged as the most promising alternatives to Pt-based electrocatalysts in hydrogen evolution reaction (HER), only a few of them (Fe-, Co-, Ni-, W-, and Mo-based materials) are used as efficient HER electrocatalysts, while others are generally considered as HER-inactive materials with poor activities. Here, a theory-guided experiment is carried out to activate titanium dioxide as a new efficient HER electrocatalyst. First-principles simulations indicate that the hydrogen adsorption free energy could be optimized through tuning the structural and electronic properties of TiO2. Then Cu-doped amorphous TiO2 is successfully prepared based on the theoretical results. The activated TiO2 expectedly shows excellent HER performance with a low overpotential of 92 mV at 10 mA cm–2 in alkaline media, which is far superior to that of the crystalline TiO2 (over 400 mV). The origin of HER activity is further investigated in detail. The corrugation of the amorphous surface helps stabilize the adsorbed water molecule, crucial for the water dissociation of the Volmer step. The Cu doping can strengthen the orbital hybridization of H1s and O2p favoring the hydrogen adsorption/desorption and improve the electrical conductivity. Our work highlights the great potential of traditionally inactive materials in HER electrocatalysis and helps deepen our understanding of the catalytic mechanism.
研究领域:
材料科学
·
电化学
·
催化
·
理论化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
OPTICAL MATERIALS
·
2025
·
IF 4.2
Yuanyuan Tian,Xinyang Zhang,Enze Wu,Shengli Liu,Bo Zhang
In this study, amorphous TiO 2 nanofilm has been prepared by a pulsed magnetron sputtering method. The uniform amorphous TiO 2 nanostructure shows the excellent electrochromic performance in visible and near-infrared bands, including the wide transmittance modulations of 63.4 % at 460 nm and 22.1 % at 2000 nm, the short switching time of 9.4 s/8.6 s for coloring/bleaching, and the large coloration efficiency of 62.4 cm 2 /C at 460 nm. Furthermore, the amorphous TiO 2 nanofilm has the feasible energy storage property. The TiO 2 film exhibits a large areal capacitance with good rate performance (9.3 mF/cm 2 ). It provides an intuitive method for monitoring energy storage through changes in TiO 2 electrode color. In addition, the oxygen concentration and sputtered time have significant effects on the microstructure, crystallization and electrochemical properties of TiO 2 films. These results have significant guiding significance for the development of amorphous TiO 2 films and related advanced dual functional devices with electrochromism and energy storage.
研究领域:
材料科学
·
电化学
·
纳米技术
·
光学材料
·
薄膜技术
✓ 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）