Nano Research
·
2023
·Vol. 16
·期 5
·6278-6289
·
IF 9.9
Xu Jialun,Zhang Zhihua,Yu Daiyi,Du Wei,Song Nan,Duan Xuezhi,Zhou Xinggui
The catalytic performances over propylene epoxidation with H 2 and O 2 (HOPO process) are significantly affected by the properties (e.g., surface properties, Ti coordination, and morphology) of titanosilicate zeolite. Introducing urea into zeolite synthesis is a simple and convenient method to modify these properties of titanosilicate zeolite. Uncalcined pore-blocked titanium silicalite-1 (TS-1, i.e., TS-1-B) with the lower urea dosage possesses more defective structure and unsaturated coordinated Ti sites verified by 29 Si nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) analysis, which results in a high initial activity and hydrogen efficiency; while the high surface acidity generated by these Ti species leads to a continuous decrease in the activity and the propylene oxide (PO) selectivity during the reaction. As the amount of urea gradually increases, the TS-1-B samples present the reduced surface defects and defective and unsaturated Ti species. Specially, TS-1-B-0.30U presents the weaker PO adsorption on PO-diffusion reflectance infrared Fourier transform spectra (DRIFTS), and thus results in the high stable PO formation rate and selectivity over its Au catalyst. Furthermore, a flat-plate-like shape with a shorter thickness of 100 nm along the b-axis direction is observed on the urea-modified TS-1. Compared with the conventional ellipsoidal TS-1 with crystal sizes of 200 and 500 nm, the flat-plate-like TS-1-0.30U displays the less surface defects, unsaturated Ti species, and the weaker Lewis acid, which is favorable for the desorption and intracrystalline diffusion of PO, thus reduces the occurrence of side reactions for the improved selectivity and stability. This work may provide a reference for developing titanium-containing materials with high activity and stability over HOPO reaction.
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ACS Applied Materials & Interfaces
·
2019
·
IF 8.456
Zhongxi Xie,Shuang Liang,Xuechao Cai,Binbin Ding,Shanshan Huang,Zhiyao Hou,Ping’an Ma,Ziyong Cheng,Jun Lin
Hypoxia and overexpression of glutathione (GSH) are typical characteristics of the tumor microenvironment, which severely hinders cancer treatments. Here, we design a novel biodegradable therapeutic system, O2–Cu/ZIF-8@Ce6/ZIF-8@F127 (OCZCF), to simultaneously achieve GSH depletion and O2-enhanced combination therapy. Notably, the doped Cu2+ doubles the O2 storage capacity of the ZIF-8 matrix, which makes OCZCF an excellent pH-sensitive O2 reservoir for conquering tumor hypoxia, enhancing the photodynamic therapy (PDT) efficiency of chlorin e6 (Ce6) under 650 nm laser irradiation. Moreover, the released Cu2+ can act as a smart reactive oxygen species protector by consuming intracellular GSH. The byproduct Cu+ will undergo highly efficient Fenton-like reaction to achieve chemodynamic therapy (CDT) in the presence of abundant H2O2. The accompanying O2 will further alleviate hypoxia. The in vitro and in vivo experimental data indicate that OCZCF could cause remarkable tumor inhibition through enhanced synergetic PDT and CDT, which may open up a new path for cancer therapy.
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COMBUSTION AND FLAME
·
2018
·
IF 4.494
Guoqing Wang,Yuyang Li,Wenhao Yuan,Yizun Wang,Zhenbiao Zhou,Yingzheng Liu,Jianghuai Cai
Bio-butanol is an important alternative fuel and has many advantages in engine combustion . In the present work, laminar flame propagation of n- butanol/air and n- butanol/(14% O 2 /86% He) mixtures was investigated using a constant-volume combustion vessel at the unburnt temperature of 423 K, initial pressures of 1–20 atm and a series of equivalence ratios. Flame instabilities of n -butanol, including cellular instability and pulsating instability, were studied based on flame morphology. The unsteady transition from weak flame to normal flame was investigated based on the flame trajectories and this phenomenon became less perceptible in the flame with stronger combustion intensity and smaller Lewis number. The accelerated laminar burning velocity (LBV), thickened flame thickness, larger Markstein length and Markstein number indicate that the thermal diffusivity of n- butanol/O 2 /He flames are greatly enhanced by helium addition. The smaller densities and lower reactant concentrations result in the smaller laminar burning fluxes of n- butanol/O 2 /He flames than those of n -butanol/air flames. The high temperature kinetic model of n -butanol reported by Cai et al. was further developed with recent theoretical progresses on n -butanol reactions. The updated high temperature model was validated on the present experimental data and a vast amount of previous n -butanol combustion data . Sensitivity analysis was performed using the updated model under wide pressure and equivalence ratio ranges. The similarity in the sensitivities indicates that the sensitive reactions in n- butanol/air flames can be validated by using n- butanol/O 2 /He flames, which greatly compensates the problem that the n- butanol/air flames are susceptible to flame instabilities at high pressures. The weaker pressure dependence of the LBVs of n -butanol/O 2 /He flames indicates that their flame chemistry changes less to resist the pressure variation.
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Advanced Materials Interfaces
·
2018
·Vol. 5
·期 22
·1801070
·
IF 4.834
Lin Fan,Doudou Lou,Haoan Wu,Xizhi Zhang,Yefei Zhu,Ning Gu,Yu Zhang
In spite of the competitive advantages, inorganic nanoparticle mimic enzymes exhibit inherent disadvantages of limited catalytic efficiency and lacking selectivity. Here, a gold nanoparticle (AuNP)-based mimic enzyme with significantly enhanced glucose selectivity and catalytic activity is constructed and demonstrated for the first time. Aminophenylboronic acid is employed to increase the affinity to glucose, as well as build molecular imprinted polymer shells to realize the selectivity for template molecules of glucose. Besides that, heptadecafluoro- n -octyl bromide nanoemulsion with the function of providing oxygen is introduced to gain a further improvement in catalytic activity, which successfully enhances the catalytic efficiency ( k cat / K m ) up to about 270-fold. Based on the demonstrated catalytic properties, AuNP-based glucose oxidase mimics are successfully applied in practical glucose detection of drinks and blood glucose.
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ACS Earth and Space Chemistry
·
2023
·
IF 3.4
Hao Tian,Xue-Bin Zhang,Yin-Ping Li,Qing He,Na-Na Tian,Song-Hai Wu,Xu Han
Although inorganic Fe(IV)═O oxo and Fe(III)-OOH peroxo have attracted more attention in aqueous environments, direct evidence for the characterization and identification of those oxidizing species is still lacking. In this study, the doped Cu/Co increases the reactivity of ferrihydrite/hematite in oxidizing As(III) by S(IV)-O2 under alkaline and dark conditions. Quenching experiments exclude the contributions of ·OH, O2•–, SO3•–, SO4•–, SO5•–, HSO5–, and H2O2 and confirm that peroxo and oxo are primary oxidizing species in As(III) oxidation. Electrochemical analyses indicate that Fe(IV)═O oxo and Fe(III)-OOH peroxo are primarily located on the surface of ferrihydrite and hematite. Selective oxidation of methyl phenyl sulfoxide and methyl phenyl sulfide to the corresponding oxidation products further reveals the presence of ≡Fe(IV)═O oxo on both ferrihydrite and hematite, and the doped Cu/Co significantly decreases the produced ≡Fe(IV)═O oxo on ferrihydrite, while increases the produced ≡Fe(IV)═O oxo on hematite. Meanwhile, selective oxidation of benzyl alcohol to benzaldehyde indicates the presence of ≡Fe(III)-OOH peroxo on both ferrihydrite and hematite, and the doped Cu/Co apparently increases the produced ≡Fe(III)-OOH peroxo on ferrihydrite and hematite. Raman analysis further reveals the presence of ≡Fe(IV)═O oxo and ≡Fe(III)-OOH peroxo on pure and metal-doped ferrihydrite/hematite, which also confirms that the doped Cu/Co decreases the produced ≡Fe(IV)═O oxo on ferrihydrite and increases ≡Fe(IV)═O oxo on hematite, while apparently increasing ≡Fe(III)-OOH peroxo on both ferrihydrite and hematite. This study enriches our understanding on the oxidizing species in the S(IV)-mediated oxidation processes under alkaline conditions, providing new insight on the oxidation reactivity of surface peroxo and oxo species mediated by the doped metal ions.
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INORGANIC CHEMISTRY COMMUNICATIONS
·
2021
·
IF 2.495
Qian-Qian Huang
A novel tetranuclear nickel(II)-flavonolate complex [Ni II 4 (fla) 4 (CH 3 O) 4 (H 2 O) 4 ] (flaH: 3-Hydroxyflavone, flavonol) was synthesized. Its crystal structure and spectroscopic features have been investigated in details by physicochemical methods and single crystal X-ray diffraction. Different from other mononuclear metal-flavonolate complexes, this complex demonstrates a cluster molecular structure which has four Ni II centers, and each Ni II centre is coordinated by a bidentate flavonolate, three methanol and a water molecule. The crystal of this complex is tetragonal crystal system: space group I 41/a, a = 24.4361(14), b = 24.4361(14), c = 12.7972 (14), α = β = γ = 90 ° , V = 7641.5 (12), Z = 4. The complex can react with O 2 , in other words, it has enzymatic reactivity just like enzyme-substrate model of quercetin 2,3-dioxygenase, and the reaction products are similar with the other reported enzyme-substrate models.
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Acta Biomaterialia
·
2022
·
IF 10.633
Furong Liu,Tao He,Songlin Gong,Meiling Shen,Shuang Ma,Xianzhou Huang,Lu Li,Li Wang,Qinjie Wu,Changyang Gong
Combining the internal force-driven chemodynamic therapy (CDT) and the external energy-triggered photodynamic therapy (PDT) holds great promise to achieve an advanced anticancer effect based on reactive oxygen species (ROS). However, the insufficient oxy-substrates supply in tumor microenvironment, like hydrogen peroxide (H 2 O 2 ) and oxygen (O 2 ), is the Achilles heel that greatly restricts the efficacy of this ROS-based treatment. Herein, the construction of a c opper p e roxide-based tumor pH-re s ponsive a utocatalytic nano r eactor (CESAR), via an albumin-mediated biomimetic mineralization strategy is described. The decoration of human serum albumin endows the nanoreactor good hydrophilicity and biocompatibility, which is highly desired for the metal-based materials. Upon exposure to acidic tumor microenvironment, CESAR presents a pH-triggered disintegration with Cu 2+ , H 2 O 2 and O 2 generated instantly. The generated H 2 O 2 complements the hyperoxide deficiency and initiates a localized Fenton-like reaction with the assistance of Cu 2+ for highly toxic hydroxyl radicals (•OH) production for improving CDT. The evolved O 2 gas enables hypoxia relief for enhanced Ce6-mediated PDT. This H 2 O 2 /O 2 self-supplying strategy significantly amplifies the tumor oxidative damage and gains an optimal treatment outcome, which offers a new paradigm for optimizing the tumor therapeutic options limited by oxide or hyperoxide deficiency, not only for CDT/PDT, but also other oxy-substrates involved strategies. Statement of significance The shortage of oxy-substrates in the tumor microenvironment remains a great challenge for ROS-based cancer therapy. Herein, we introduce human serum albumin as a scaffold to stabilize copper peroxide nanomaterials for constant production of H 2 O 2 and O 2 to enhance chemodynamic/photodynamic therapy. The tumor pH-triggered H 2 O 2 /O 2 production and Cu 2+ release are confirmed, assuring the strategy of a highly precise, effective way to destroy tumor without any side effects. This work lends new and exciting insights into the engineering design of autocatalytic oxy-substrates self-supply nanoreactor for overcoming the bottlenecks, like the oxy-substrates deficiency of CDT/PDT and the poor stability of metal peroxides, to achieve highly effective chemodynamic/photodynamic therapy.
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JOURNAL OF NANOBIOTECHNOLOGY
·
2024
·Vol. 22
·期 1
·1-15
·
IF 10.6
Li Jingchao,Wang Tingting,Shi Yuanfei,Ye Zichen,Zhang Xun,Ming Jiang,Zhang Yafei,Hu Xinyan,Li Yun,Zhang Dongsheng,Xu Qianhe,Yang Jun,Chen Xiaolan,Liu Nian,Su Xinhui
Radionuclides internal radiotherapy (RIT) is a clinically powerful method for cancer treatment, but still poses unsatisfactory therapeutic outcomes due to the hypoxic characteristic of tumor microenvironment (TME). Catalase (CAT) or CAT-like nanomaterials can be used to enzymatically decompose TME endogenous H 2 O 2 to boost TME oxygenation and thus alleviate the hypoxic level within tumors, but their effectiveness is still hindered by the short-lasting of hypoxia relief owing to their poor stability or degradability, thereby failing to match the long therapeutic duration of RIT. Herein, we proposed an innovative strategy of using facet-dependent CAT-like Pd-based two-dimensional (2D) nanoplatforms to continuously enhance RIT. Specifically, rationally designed 2D Pd@Au nanosheets (NSs) enable consistent enzymatic conversion of endogenous H 2 O 2 into O 2 to overcome hypoxia-induced RIT resistance. Furthermore, partially coated Au layer afford NIR-II responsiveness and moderate photothermal treatment that augmenting their enzymatic functionality. This approach with dual-effect paves the way for reshaping TME and consequently facilitating the brachytherapy ablation of cancer. Our work offers a significant advancement in the integration of catalytic nanomedicine and nuclear medicine, with the overarching goal of amplifying the clinical benefits of RIT-treated patients. Graphical abstract
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ACS Applied Materials & Interfaces
·
2024
·
IF 8.3
Liying Hao,Jikui Sun,Qingyin Wang,Haijiao Xie,Xiangui Yang,Qiang Wei
As an atom-economical reaction, the direct generation of dimethyl carbonate (DMC) and ethylene glycol (EG) via the transesterification of CH3OH and ethylene carbonate (EC) has several promising applications, but the exploration of carriers with high specific surface areas and novel heterogeneous catalysts with more basic sites remains a long-standing research challenge. For this purpose, herein, a nitrogen-doped mesoporous carbon (NMC, 439 m2/g) based K–O2 Lewis base catalyst (K–O2/NMC) with well-dispersed strongly basic sites (2.23 mmol/g, 84.5%) was designed and synthesized. The compositions and structures of NMC and K–O2/NMC were comprehensively investigated via Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, N2 adsorption–desorption, CO2 temperature-programmed desorption, and contact angle measurements. The optimal structural configuration and electron cloud distribution of the K–O2/NMC catalyst were simulated using first-principles calculations. The electron transfer predominantly manifested as a flow from K–O to C–O/C–N, and the interatomic interactions between each atom were enhanced and exhibited a tendency for a more stable state after redistribution. Furthermore, the adsorption energies (Eads) of CH3OH at K–O–O and K–O–N sites were −1.4185 eV and −1.3377 eV, respectively, and the O atom in CH3OH exhibited a stronger adsorption tendency for the K atom at the K–O–O site. Under the optimal conditions, the EC conversion, DMC/EG selectivity, and turnover number/frequency were 80.9%, 98.6%/99.4%, and 40.5/60.8 h–1, respectively, with a reaction rate constant (k) of 0.1005 mol/(L·min). Results showed that the heterogeneous K–O2/NMC catalyst prepared herein greatly reduced the reaction cost while guaranteeing the catalytic effect, and the whole system required a lower reaction temperature (65 °C), a shorter reaction time (40 min), and a lower catalyst amount (2.0 wt % of EC). Therefore, K–O2/NMC can be used as a catalyst in different transesterification reactions.
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ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2016
·
IF 5.393
Ting Liu,Lucheng Xue,Xin Guo,Jia Liu,Yu Huang,Chuguang Zheng
The reaction mechanisms of a mixture gas of HCl, O2, and SO2 in Hg0 adsorption on α-Fe2O3(001) surface are clarified by a group of adsorption experiments and theoretical calculations based on the density functional theory. The role of O2 in removing Hg0 is greatly influenced by the reaction temperature, meanwhile, the O atom coverage could affect the adsorption performance of Hg0. The dissociated O2 competes with the active sites of Cl species on Fe surface at low temperature, however, at medium temperature HCl and O2 could simultaneously facilitate the Hg0 transformation. Combined with the theoretical calculations, the role of SO2 and the probable pathways in removing Hg0 are discussed. Lower concentration of SO2 as well as HCl could dissociate on α-Fe2O3(001) surface, and the intermediates combine with gaseous Hg0, forming mercury–sulfur, mercury–chlorine compounds, and so forth. In addition, the different concentrations of SO2 are also discussed, and the corresponding X-ray photoelectron spectroscopy analysis on contrasted samples is conducted to research the morphological characterization, providing a reliable basis for judging the probable pathways of Hg0 transformation.
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Small
·
2016
·Vol. 12
·期 39
·5477-5487
·
IF 8.315
Zhifang Ma,Mengchao Zhang,Xiaodan Jia,Jing Bai,Yudi Ruan,Chao Wang,Xuping Sun,Xiue Jiang
Local hypoxia in tumors, as well as the short lifetime and limited action region of 1 O 2 , are undesirable impediments for photodynamic therapy (PDT), leading to a greatly reduced effectiveness. To overcome these adversities, a mitochondria-targeting, H 2 O 2 -activatable, and O 2 -evolving PDT nanoplatform is developed based on Fe III -doped two-dimensional C 3 N 4 nanofusiform for highly selective and efficient cancer treatment. The ultrahigh surface area of 2D nanosheets enhances the photosensitizer (PS) loading capacity and the doping of Fe III leads to peroxidase mimetics with excellent catalytic performance towards H 2 O 2 in cancer cells to generate O 2 . As such tumor hypoxia can be overcome and the PDT efficacy is improved, whilst at the same time endowing the PDT theranostic agent with an effective T 1 -weighted in vivo magnetic resonance imaging (MRI) ability. Conjugation with a mitochondria-targeting agent could further increase the sensitivity of cancer cells to 1 O 2 by enhanced mitochondria dysfunction. In vitro and in vivo anticancer studies demonstrate an outstanding therapeutic effectiveness of the developed PDT agent, leading to almost complete destruction of mouse cervical tumor. This development offers an attractive theranostic agent for in vivo MRI and synergistic photodynamic therapy toward clinical applications.
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Catalysis Science & Technology
·
2024
·
IF 4.4
Renjie Deng,Huajie Liu,Haishuai Cui,Yao Tian,Hai Yang
In this work, we have developed a green method for the preparation of para-nitrotoluene through the catalytic nitration of toluene with nitrogen dioxide (NO2) under the promotion of dioxygen (O2). The experimental results reveal that the dealumination of Hβ zeolite has a significant effect on the catalysis of the developed NO2–O2–acetic anhydride (Ac2O) system, in which the conversion of toluene is 78.1% and the selectivity to para-nitrotoluene is 71.8%. Furthermore, the nature of different dealuminated catalysts was investigated by nitrogen adsorption–desorption analysis, X-ray diffraction (XRD), Fourier-transform infrared (FT-IR), thermal gravimetric analysis (TGA), inductively coupled plasma (ICP), ammonia temperature-programmed desorption (NH3-TPD), pyridine adsorbed Fourier-transform infrared (Py-FT-IR), scanning electron microscopy (SEM) and 27Al magic-angle spinning nuclear magnetic resonance (27Al MAS NMR) techniques. The results of characterization indicate that the structure of the Hβ zeolite still remains and that of Al species in the extra-framework is preferentially removed after acid treatment. Based on the combined results of catalytic characterization and DFT calculation, a feasible reaction mechanism of improved para-selectivity in toluene nitration was suggested for the NO2–O2–Ac2O system.
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