APPLIED CATALYSIS A-GENERAL
·
2014
·
IF 3.674
Lei Zeng,Wulin Song,Minghui Li,Xiaoqin Jie,Dawen Zeng,Changsheng Xie
Nitrogen-doped TiO 2 nanomaterial attracts enormous attention due to its excellent visible photocatalytic activity. A simple annealing method assisted by adjusting gas composition to control the positions of nitrogen dopants in TiO 2 lattice is presented. The nitrogen doping sites are confirmed by XPS. The photo-degradation results of gaseous benzene under visible light illumination reveal that photocatalytic activity in as-prepared samples containing the substitutional nitrogen species is higher than that in samples containing interstitial nitrogen species. The improvement of photocatalytic performance is ascribed to the increased amounts of surface hydroxyl group in N-TiO 2 samples. The efficient separation of electron-hole pairs was also responsible for the enhanced photocatalytic activity. In addition, an important conclusion is pointed out: the presence of oxygen during annealing process has an important effect on the formation of interstitial nitrogen dopants. The present work is believed to have guiding significance for preparing nitrogen-doped TiO 2 with high photocatalytic activity.
✓ 已验证
DOI
高影响因子
DALTON TRANSACTIONS
·
2017
·Vol. 47
·期 2
·348-356
·
IF 4.029
Hao Xu,Dongsheng Dai,Songsong Li,Lei Ge,Yangqin Gao
Semiconductor-based photocatalytic hydrogen evolution from water with earth-abundant and low cost co-catalysts has attracted much attention. Herein, novel Cu2(OH)2CO3 decorated 2D TiO2 nanosheets for photocatalytic water splitting were synthesized by a facile in situ synthetic method. The chemical and photophysical properties of Cu2(OH)2CO3/TiO2 nanosheets were investigated by X-ray diffractometry (XRD), transmission electron microscopy (TEM), UV-vis diffusion reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry (CV) analysis. At an optimal Cu2(OH)2CO3 loading content of 1.5 mol%, the hybrid photocatalyst delivers a high photocatalytic H2 production rate of 1555.07 μmol g−1 h−1. Such enhanced photocatalytic activity is attributed to tight interfaces formed between Cu2(OH)2CO3 nanoparticles and TiO2 nanosheets, which play a vital role in the separation of photo-excited carriers, and the formation of active Cu1+ and Cu0 species can also benefit the charge separation process by reducing the over-potential of water reduction. Based on the above results, a possible mechanism is proposed and further verified using photoluminescence (PL) spectra. This work may provide more insight into the synthesis of novel Cu2(OH)2CO3/TiO2 nanosheets with high photocatalytic H2 evolution activity for solar-to-chemical conversion and utilization.
✓ 已验证
DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2024
·Vol. 137
·期 3
·1535-1552
·
IF 1.7
Feng Shangzhen,Zhou Hantao,Jiang Huanjin,Yang Jie,Chen Jixiang
Herein, the Ni–Co alloy supported on TiO 2 catalysts were prepared by sol–gel method assisted with Polymethyl Methacrylate (PMMA) template, and they were tested for in situ aqueous phase hydrodeoxygenation (HDO) of methyl palmitate to hydrocarbons using methanol as hydrogen donor. It has been found that the introduction of PMMA decreases the Ni–Co alloy particles size, reduces the metal-support interactions (SMSI), constructs the mesopores and enlarges the mesopore size. Also, the Ni–Co alloy particles can be partially embedded in TiO 2 , beneficial to the catalyst stability since the sintering and leaching of the Ni–Co alloy particles can be suppressed under hydrothermal condition. In the in situ HDO of methyl palmitate, the main deoxygenation pathway is decarboxylation/decarbonylation on the Ni–Co alloy catalysts. The catalysts prepared with PMMA exhibits higher activity than that without PMMA, giving the pentadecane yield of 86.2% at 310 °C. This is ascribed to their more exposed active sites and wider mesopores. Moreover, the catalyst is not obviously deactivated during five reactions.
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2018
·Vol. 11
·期 16
·2766-2775
·
IF 7.411
Yunpeng Liu,Yuhang Li,Siyuan Yang,Yuan Lin,Jiangliang Zuo,Hong Liang,Feng Peng
Reduction is considered to be an effective method to improve the photocatalytic activity of TiO 2 ; however, the underlying relationship between structure and photocatalytic performance has not been adequately unveiled to date. To obtain insights into the effect of structure on photocatalytic activity, two types of reduced TiO 2 were prepared from CO (CO-TiO 2 ) and H 2 (H-TiO 2 ). For H-TiO 2 , Ti−H bonds and oxygen vacancies are formed on the surface of H-TiO 2 , which results in a more disordered surface lattice. However, for CO-TiO 2 , more Ti−OH bonds are formed on the surface and more bulk oxygen vacancies are introduced; the disorder layer of CO-TiO 2 is relatively thin, owing to most surface vacancies being filled by Ti−OH bonds. Under simulated solar irradiation, the photocatalytic H 2 evolution rate of CO-TiO 2 reaches 7.17 mmol g −1 h −1 , which is 4.14 and 1.50 times those of TiO 2 and H-TiO 2 , respectively. The photocatalytic degradation rate constant of methyl orange on CO-TiO 2 is 2.45 and 6.39 times those on H-TiO 2 and TiO 2 . The superior photocatalytic activity of CO-TiO 2 is attributed to the effective separation and transfer of photogenerated electron–hole pairs, due to the synergistic effects of oxygen vacancies and surface Ti−OH bonds. This study reveals the relationship between the photocatalytic properties and structure, and provides a new method to prepare highly active TiO 2 for H 2 production and environmental treatment. Graphical Turn up the gas ! To obtain insights into the effect of structure on photocatalytic activity, two types of reduced TiO 2 are prepared from CO (CO-TiO 2 ) and H 2 (H-TiO 2 ). CO-TiO 2 exhibits a higher photocatalytic activity than that of H-TiO 2 due to the synergistic effects of oxygen vacancies and surface Ti−OH bonds.
✓ 已验证
DOI
高影响因子
Science China-Materials
·
2018
·Vol. 61
·期 6
·822-830
·
IF 4.318
Xiao Fang,Zhou Wei,Sun Bojing,Li Haoze,Qiao Panzhe,Ren Liping,Zhao Xiaojun,Fu Honggang
Oxygen vacancy (V O ) plays a vital role in semiconductor photocatalysis. Rutile TiO 2 nanomaterials with controllable contents of V O (0–2.18%) are fabricated via an in situ solid-state chemical reduction strategy, with color from white to black. The bandgap of the resultant rutile TiO 2 is reduced from 3.0 to 2.56 eV, indicating the enhanced visible light absorption. The resultant rutile TiO 2 with optimal contents of V O (∼2.07%) exhibits a high solar-driven photocatalytic hydrogen production rate of 734 μmol h −1 , which is about four times as high as that of the pristine one (185 μmol h −1 ). The presence of V O elevates the apparent Fermi level of rutile TiO 2 and promotes the efficient electronhole separation obviously, which favor the escape of photogenerated electrons and prolong the life-time (7.6×10 3 ns) of photogenerated charge carriers, confirmed by scanning Kelvin probe microscopy, surface photovoltage spectroscopy and transient-state fluorescence. V O -mediated efficient photogenerated electron-hole separation strategy may provide new insight for fabricating other high-performance semiconductor oxide photocatalysts.
✓ 已验证
DOI
高影响因子
Journal of Physical Chemistry C
·
2024
·
IF 3.3
Cong Fu,Lingfang Liu,Cici Wang,Weixin Huang,Guofeng Zhao
Unraveling the effect of defects on the concentration of surface-available photoexcited charges is of great importance for semiconductors in photocatalysis. Herein, by using in situ diffuse-reflectance infrared (IR) spectroscopy, the concentration of surface-available photoholes on TiO2 nanoparticles with tunable bulk/surface defects was quantified by an adsorbate (methanol) surface elementary reaction kinetic analysis method. Reaction kinetics showed that the oxidation of the adsorbed methanol species under light irradiation was a first-order reaction. Therefore, the concentration of surface-available photoholes can be calculated from the rate constants of adsorbed methanol on the TiO2 surface. By carefully comparing the specific reaction rate constants on the TiO2 surface with various bulk/surface defect ratios, we demonstrated for the first time that increasing the bulk defect concentration relative to the surface defects decreases the concentration of surface-available photoholes. This trend implicates different effects of bulk and surface defects on band bending and subsequent interfacial hole transfer processes in TiO2 nanoparticles. These insights not only reveal the mechanistic role of surface and bulk defects in photocatalysis but also highlight that in situ IR spectroscopy combined with reaction kinetic analysis has enormous potential in elucidating photocatalytic mechanisms.
✓ 已验证
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 129
·107150-107157
·
IF 3.84
Hang Zhang,Zipeng Xing,Yan Zhang,Zhenzi Li,Xiaoyan Wu,Chuntao Liu,Qi Zhu,Wei Zhou
A novel Ni2+ and Ti3+ co-doped porous black anatase TiO2 is successfully synthesized by a facile sol–gel technique combined with an in situ solid-state chemical reduction approach, followed by mild calcinations (350 °C) in argon atmosphere. The obtained photocatalysts are characterized in detail by X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, electron paramagnetic resonance, N2 adsorption, and transmission electron microscopy. The results indicate that the Ni2+ and Ti3+ elements are co-doped into the lattice of anatase TiO2. The prepared Ni2+/Ti3+ co-doped black anatase TiO2 possesses a mesoporous structure, consisting of disordered Ti3+ and oxygen vacancy layers. Based on UV-vis diffuse reflectance spectra and valence band analysis, the doped Ni2+ and Ti3+ species can significantly narrow the band gap of anatase TiO2 due to the formation of mid-gap states, which allows utilization of visible-light and prevents fast recombination of photogenerated charges effectively. Furthermore, the prepared co-doped photocatalysts exhibit unprecedented higher photocatalytic activity than that of the pure TiO2 and the Ni2+ doped TiO2. The degradation ratio of methyl orange and rhodamine B is up to 95.38 and 95.86%, respectively, within 150 min irradiation of visible-light by the obtained Ni2+/Ti3+ co-doped porous black anatase TiO2. The high visible-light photocatalytic degradation performance may be ascribed to the efficient doping of Ni2+ and Ti3+ in favor of the absorption of visible-light and the separation of photogenerated charges, and the porous structure facilitating the diffusion of reactants and products.
✓ 已验证
DOI
高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2013
·Vol. 28
·期 6
·832-839
·
IF 1.713
Ruxangul Jamal,Weiwei Shao,Feng Xu,Tursun Abdiryim
Polyaniline/nano titanium dioxide/graphene nanoplatelet (PANI/TiO2/G) composite was synthesized by mechanochemical route. The structure and morphology of the composite were characterized by Fourier transform infrared spectra, ultraviolet-visible absorption spectra, x-ray diffraction and transmission electron microscopy. The electrochemical performances of the composite were investigated by galvanostatic charge-discharge, cyclic voltammetry, cycling stability and electrochemical impedance spectroscopy. The structure and properties of PANI/TiO2/G composite were compared with that of polyaniline/ graphene nanoplatelet (PANI/G) composite prepared under the same polymerization conditions. After comparative analysis with PANI/G, the effects of the nano titanium dioxide (TiO2) on the structural and physicochemical properties of the PANI/G have been discussed in depth. The comparison suggested that the PANI/TiO2/G composite has higher oxidation degree and lower crystallinity than PANI/G due to the addition of nano-TiO2. Morphology studies showed that PANI and nano-TiO2 particles were both observed on the bent and flat surfaces of graphene nanoplatelet in the PANI/TiO2/G composite. The electrochemical tests showed that the PANI/TiO2/G composite displayed a higher electrochemical activity with specific capacitance of 516 F/g (3 mA/cm2) and better cycle stability than PANI/G.
✓ 已验证
DOI
高影响因子
Nanoscale Horizons
·
2018
·Vol. 4
·期 2
·452-456
·
IF 9.391
Yong Zhang,Wenxin Xu,Xiaojie Xu,Wei Yang,Siyuan Li,Jiaxin Chen,Xiaosheng Fang
It has always been a challenge to prepare self-powered ultraviolet photodetectors (UV PDs) utilizing a green, facile and low-cost method. Here, we provide such an approach for fabricating self-powered photodetectors based on Te nanowire/TiO2 nanoparticle (NP) and Te nanowire/ZnO nanoparticle (NP) heterojunctions. It is noteworthy that such devices were prepared via simply brushing non-toxic solution-processed Te nanowires and commercial TiO2 and ZnO nanoparticles onto paper. The as-obtained UV PDs can work under zero bias due to photovoltaic effects from the Te/TiO2 and Te/ZnO heterojunctions. This study not only presents high-performance UV PDs, but also provides a general and effective method for developing environmentally-friendly and energy-efficient optoelectronic devices for practical applications. The concept of employing daily-use brushes and recyclable paper provides a facile way to fabricate green low-cost PDs.
✓ 已验证
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2014
·
IF 4.908
He Chen,Qian Lin,Qiang Xu,Yang Yang,Zongping Shao,Yong Wang
Atomic layer deposition (ALD) of TiO 2 was applied on porous polypropylene (PP) membranes which were used as separators in lithium-ion batteries (LIBs) composed of Li 4 Ti 5 O 12 (LTO) anode/Li cathode. Without plasma activation on the bare PP membrane, the initial deposition of TiO 2 was based on the subsurface nucleation mechanism , which prevented the formation of a conformal hydrophilic TiO 2 layer at low ALD cycles. The improvement of wettability of the PP membrane to the electrolyte could only be achieved at high ALD cycles up to 500. However, the severe narrowing of membrane pores counterbalanced the wetting enhancement, which hardly improved the performance of the LIBs. Plasma pretreatment was efficient to generate active groups on the highly chemically inert surface of polypropylene membranes, thus ultrathin TiO 2 films could be conformally deposited by ALD on the membrane surface based on the layer-by-layer mechanism at cycles as low as 20. Such a conformal ultrathin layer of TiO 2 was confirmed to concurrently overcome both the thermal shrinkage and poor wettability of the PP membranes. Beneficial from the improved wettability at no expense of pore size, the electrochemical performances of LIBs such as specific discharge capacities at different discharge rates were upgraded.
✓ 已验证
DOI
高影响因子
Nano Research
·
2021
·Vol. 15
·期 2
·933-941
·
IF 8.897
Zhen Mengmeng,Jiang Keliang,Guo Sheng-Qi,Shen Boxiong,Liu Huiling
The shuttle effect of lithium polysulfides (LiPSs) in lithium-sulfur batteries (LSBs) has been hampered their commercialization. Metal oxides as separator modifications can suppress the shuttle effect. Since there is no direct electron transport between metal oxides and LiPSs, absorbed LiPSs should be diffused from the surface of metal oxides to the carbon matrix to go through redox reactions. If diffusivity of LiPSs from metal oxides surface to carbon substrate is poor, it would hinder the redox reactions of LiPSs. Nevertheless, researchers tend to focus on the adsorption and overlook the diffusion of LiPSs. Herein, same morphology and different crystal phase of TiO 2 nanosheets grown on carbon nanotubes (CNTs@TiO 2 -bronze and CNTs@TiO 2 -anatase) have been designed via a simple approach. Compared with CNTs and CNTs@TiO 2 -anatase composites, the battery with CNTs@TiO 2 -bronze modified separator delivers higher specific capacities and stronger cycling stability, especially at high current rates (∼ 472 mAh·g −1 at 2.0 C after 1,000 cycles). Adsorption tests, density functional theory calculations and electrochemical performance evaluations indicate that suitable diffusion and adsorption for LiPSs on the CNTs@TiO 2 -B surface can effectively capture LiPSs and promote the redox reaction, leading to the superior cycling performances.
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2026
·
IF 5.8
Yangguang Zhu,Jun Peng,Chen Ye,Cheng-Te Lin
TiO 2 nanosheets with rutile as the principle crystalline phase were prepared through the in-situ electrochemical oxidation of Ti 3 C 2 T x nanosheets. • Electrochemical transformation method exhibits higher efficiency in inducing the anatase-to-rutile phase transition than the conventional method of high-temperature heating. • Our study elucidates the mechanism underlying the structural evolution and phase transition in TiO 2 nanosheets from a thermodynamic perspective, offering valuable insights for the rational design of biosensing platforms towards biomolecules. Two-dimensional TiO 2 nanosheets (NS) enable efficient stabilization of aptamers and enhanced electron transfer on electrode surface for electrochemical biosensing applications. However, the effect of morphology and crystalline phase of TiO 2 NS on its detection performance towards biomolecules are unclear. Meanwhile, the mechanism underlying the structural evolution and anatase-to-rutile phase transition in TiO 2 NS via electrochemical transformation remains elusive. Thus, TiO 2 NS with rutile as the principal crystalline phase were prepared through the in-situ electrochemical oxidation of Ti 3 C 2 T x NS, offering a more accessible and sustainable alternative method compared to previously reported approaches. Density functional theory simulations demonstrated that electrochemical transformation method minimizes the phase transition energy difference and accelerates the phase transition. TiO 2 NS-based electrodes presented a low detection limit of 10.2 nM towards UA with sensitivity as 1.924 μA . cm –2. μM –1 (0.03–0.3 μM) and linear range from 0.03–0.3 and 0.03–300 μM, and achieved acceptable stability, interference resistance, temperature adaptability and feasibility in urine sample analysis. Our approach exhibits higher efficiency in inducing the anatase-to-rutile phase transition than the conventional method of high-temperature heating. Thus, our study elucidates the mechanism underlying the structural evolution and phase transition in TiO 2 NS from a thermodynamic perspective, offering valuable insights for the rational design of biosensing platforms towards biomolecules. TiO 2 nanosheets (NS) was in-situ fabricated and grown on the surface of Ti 3 C 2 T x NS controllably via the electrochemical oxidation of Ti 3 C 2 T x NS in the electrochemical reactor, as shown in Figure a. Extending the oxidation time leads to a monotonic increase in the surface coverage of TiO 2 nanoparticles (NP) until full coverage is achieved. Our synthesized TiO 2 NS exhibits superior electrochemical performance, owing to their increased surface-to-volume ration, shorter ion diffusivity paths, faster electron transferring and efficient immobilization of aptamers. Density functional theory simulations demonstrated that electrochemical transformation method minimizes the phase transition energy difference and accelerates the phase transition (Figure b). Our approach exhibits higher efficiency in inducing the anatase-to-rutile phase transition than the conventional method of high-temperature heating. Download: Download high-res image (252KB) Download: Download full-size image
✓ 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）