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mechanochemical synthesis of Visible-light Induced Photocatalyst with Nitrogen and Carbon Doping

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过程工程学报 2006年第3期6卷 477-481页

作者：殷澍 Maskazu Komatsu 张其武李锐星唐清 Fumio Saito Tsugio Sato Inst. Multidisciplinary Research for Advanced Materials Tohoku Univ.2-1-1KatahiraAoba-kuSendaiMiyagi 980-8577Japan

Nitrogen and/or carbon doped titania photocatalysts were prepared by a novel mechanochemical method. The prepared powders possessed two absorption edges around 400 and 540 nm wavelengths and showed excellent photocatalytic ability for nitrogen monoxide oxidation under visible light irradiation. Under the irradiation of visible light of wavelength >510 nm,37% of nitrogen monoxide could be continuously removed by the carbon and nitrogen co-doped titania prepared by planetary ball milling of P-25 titania–10% hexamethylenetetramine mixture followed by calcination in air at 400-C.

关键词： mechanochemical synthesis titania photocatalyst carbon and nitrogen doping nitrogen monoxide oxidation

ZnS Semiconductive Powder Doped with Transition Metal Ions via mechanochemical synthesis Technique

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过程工程学报 2004年第z1期4卷 424-430页

作者： R.F. Louh C.K. Lin Oscar Lin G.S. Chen C.C. Chan Dept. of Mater. Sci. & Eng. Feng Chia University Taichung 407 China Dept. of Chem. Eng. Feng Chia University Taichung 407 China

The solid state synthesis can be carried out by using the initial pure metal zinc and inorganic sulfur powder mixtures by means of the mechanochemical synthesis route. The completion of solid state reaction between pure zinc and sulfur powder to produce c-ZnS and h-ZnS phases via such a route was rather fast, as compared to other non-sulfide systems by the similar method. The study was aimed to investigate the microstructure development and phase formation through the solid state reaction by controlling the processing parameters involved in this process including grinding media to powder weight ratio, solid state reaction duration, reaction atmosphere, stoichiometric ratio of zinc and sulfur elements, grinding media and choice of minor additives such as teflon-based polymeric lubricants and transition metal dopants (Mn, Cu). Both as-synthesized powders and heat-treated ZnS materials with various stoichiometric ratios were characterized by XRD, EXAFS and XANES analysis. The interesting results from X-ray absorption spectroscopy (XAS) would provide us some strong evidence whether stoichiometric and non-stoichiometric ZnS material can be successfully formed. The minor amount (0.5wt%)of Mn+2 or Cu+2 ion dopants added to the powder batch with the Zn/S stoichiometric ratio between1.00 to 1.05 was found to favor the reaction rate in the mechanochemical synthesis. Moreover, the obtained results of ZnS phase development under reaction conditions and different transition metal dopants in this study would imply that synthesis of other kind of sulfide compounds can be achieved using the demonstrated technique.

关键词： mechanochemical synthesis ZnS powder,semiconductor powder synthesis solid sate reaction transition metal ions

ZnS Semiconductive Powder Doped with Transition Metal Ions via mechanochemical synthesis Technique

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Enthalpy-change driven synthesis of high-entropy perovskite nanoparticles

中国颗粒学会2004年年会暨海峡两岸颗粒技术研讨会会议

作者： R.F.Louh C.K.Lin Oscar Lin G.S.Chen C.C.Chan Dept.of Mater.Sci.＆Eng.Feng Chia University Taichung 407China Dept.of Mater.Sci.＆Eng.Feng Chia University Taichung 407China Dept.of Mater.Sci.＆Eng.Feng Chia University Taichung 407China Dept.of Mater.Sci.＆Eng.Feng Chia University Taichung 407China Dept.of Chem.Eng. Feng Chia UniversityTaichung 407China

＜正＞The solid state synthesis can be carried out by using the initial pure metal zinc and inorganic sulfur powder mixtures by means of the mechanochemical synthesis route. The completion of solid state reaction between pure zinc and sulfur powder to produce c-ZnS and h-ZnS phases via such a route was rather fast, as compared to other non-sulfide systems by the similar method. The study was aimed to investigate the microstructure development and phase formation through the solid state reaction by controlling the processing parameters involved in this process including grinding media to powder weight ratio, solid state reaction duration, reaction atmosphere, stoichiometric ratio of zinc and sulfur elements, grinding media and choice of minor additives such as teflon-based polymeric lubricants and transition metal dopants （Mn, Cu）. Both as-synthesized powders and heat-treated ZnS materials with various stoichiometric ratios were characterized by XRD, EXAFS and XANES analysis. The interesting results from X-ray absorption spectroscopy （XAS） would provide us some strong evidence whether stoichiometric and non-stoichiometric ZnS material can be successfully formed. The minor amount （0.5 wt%）of Mn+2 or Cu+2 ion dopants added to the powder batch with the Zn/S stoichiometric ratio between 1.00 to 1.05 was found to favor the reaction rate in the mechanochemical synthesis. Moreover, the obtained results of ZnS phase development under reaction conditions and different transition metal dopants in this study would imply that synthesis of other kind of sulfide compounds can be achieved using the demonstrated technique.

关键词： mechanochemical synthesis ZnS powder, semiconductor powder synthesis solid sate reaction transition metal ions

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Nano Research 2022年第6期15卷 4867-4872页

作者： Siyang Nie Liang Wu Lingci Zhao Pengfei Zhang School of Chemistry and Chemical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

Due to their diverse and tunable composition,distorted lattice and excellent stability,high-entropy ceramics(HECs)hold great promise for catalysis,especially when they present as nanoparticles(NPs).However,current HECs are typically limited to bulky materials with none or fewer defects,because high synthetic temperature(e.g.,1,000–1,200°C)is usually required to highlight the entropic contribution(TΔS)inΔG=ΔH−TΔS.Being different with previous strategies,a negative Gibbs free energy for HECs crystallization is obtained by dramatically decreasing the mixing enthalpy(ΔH).Guided by this principle,single-phase highentropy La(Ni_(0.2)Mn_(0.2)Cu_(0.2)Fe_(0.2)Co_(0.2))O_(3−δ)perovskite(HE-LMO)NPs were prepared at a relatively low temperature(≤500°C).Interestingly,abundant oxygen vacancies were directly created within HE-LMO NPs,which exhibited good activity in catalytic oxidation.Meanwhile,the high-entropy structure endows as-made HE-LMO with robust stability even with 5 vol.%water in feeding gas.Density functional theory(DFT)calculations revealed that the defective sites in HE-LMO NPs facilitated the charge transfer from HE-LMO to CO,thus activating the adsorbed CO gas.The current work may inspire future design and synthesis of HECs NPs.

关键词： enthalpy-change high-entropy ceramics mechanochemical synthesis perovskite CO oxidation

Nanocrystalline Growth Activation Energy of Zirconia Polymorphs Synthesized by mechanochemical Technique

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Journal of Materials Science & Technology 2014年第4期30卷 387-393页

作者： Taghi Dallali Isfahani Jafar Javadpour Alireza Khav Massoud Goodarzi Hamid Reza Rezaie Department of Materials Science and Engineering Golpayegan University of Technology School of Metallurgy and Materials Engineering Iran University of Science and Technology(IUST)

The synthesis of ZrO2 by mechanochemical reaction using ZrCI4 and CaO as raw materials and subsequent annealing of the products were investigated. The effect of thermal treatment on the structural evolution and morphological characteristics of the nanopowders was studied by X-ray diffractometry, Raman spectroscopy, transmission electron microscopy, scanning electron microscopy, differential thermal analysis and Rietveld refinement. The results showed that the average crystallite size of Zr02 was less than 100 nm up to around 1100 ℃. The activation energy for ZrO2 nanocrystallite growth during calcination was calculated to be about 13,715 and 27,333 J/too Mechanism of the nanocrysta for tetragonal （t-ZrO2） and monoclinic （m-Zr02） polymorphs, respectively. ite growth of the ZrO2 polymorphs during annealing is primarily investigated.

关键词： Zirconia nanoparticles mechanochemical synthesis Characterization methods Activation energy Phase transformation

Role of MgF2 addition on high energy ball milled kalsilite:Implementation as dental porcelain with low temperature frit

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Journal of Advanced Ceramics 2014年第4期3卷 332-338页

作者： Pattem Hemanth KUMAR Abhinav SRIVASTAVA Vijay KUMAR Nandini JAISWAL Pradeep KUMAR Vinay Kumar SINGH Department of Ceramic Engineering Indian Institute of Technology(BHU)VaranasiIndia Department of Chemical Engineering Indian Institute of Technology(BHU)VaranasiIndia

Porcelain fused to metal(PFM)has received great attention over the last few years due to its importance in the dentistry.Kalsilite(K_(2)O·Al_(2)O_(3)·SiO_(2))is a high thermal expansion porcelain,suitable for bonding to metals.However,kalsilite is a metastable phase which gets converted into crystalline leucite upon heating.In the current work feasibility of developing stable kalsilite phase,dispersion of MgF2 in it as an additive and using mechanochemical synthesis are studied.Micro fine dental material has been formulated by mixing prepared kalsilite with low temperature frit(LTF)in different ratio.The crystalline phases evolved in fired powders are characterized by powder X-ray diffraction(XRD)technique.Kalsilite with different ratio of LTF has been cold pressed and heat treated to examine its coefficient of thermal expansion(CTE),flexural strength,apparent porosity(AP),bulk density(BD)and microstructure.Results indicate that MgF_(2) addition and high milling duration help in kalsilite stabilization.Temperature also plays an important role in this stabilization,and at 1100℃single phase kalsilite formation is observed.Present outcomes demonstrate that it is easily possible to synthesize a stable single phase kalsilite with desirable properties.

关键词： kalsilite porcelain fused to metal(PFM) dental ceramic mechanochemical synthesis thermal expansion X-ray diffraction(XRD)

Solar Photocatalysis of TiO₂ Supported Natural Palygorskite Nanofibers Elaborated by a One_Pot mechanochemical Route

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Journal of Minerals and Materials Characterization and Engineering 2022年第3期10卷 254-274页

作者： Lakbita Omar Rhouta Benaissa Goetz Vincent Maury Francis Plantard Gaël Daoudi Lahcen Mohammed VI Polytechnic University (UM6P) Marrakech Morocco IMED_Lab Faculty of Sciences and Technologies Cadi Ayyad University Marrakech Morocco PROcédés Matériaux et Energie Solaire Rambla de la Thermodynamique PROMES_CNRS UPR 8521 Perpignan France CIRIMAT Université de Toulouse Toulouse France Laboratoire de Geoscience et Géoenvironnement Faculté des Sciences et Techniques Guéliz Université Cadi Ayyad Marrakech Morocco

This study reports the successful synthesis of supported TiO2_Palygorskite nanocomposites by a one-pot dry mechanochemical route. Indeed, the elaboration procedure involved an in-situ reaction between accessories carbonates present in raw fibrous palygorskite clay and titanyl sulfate (TiOSO4) precursor under variable grinding conditions, essentially ball/solid matter mass ratio and rotation velocity. This yielded after air annealing at 600%C for 1 h to the immobilization of anatase TiO2 nanoparticles (≈8 nm of average size) as evidenced by XRD and TEM analyses. Once the conditions of elaboration were optimized, the photocatalytic properties were evaluated under 3 conditions: artificial UV radiation, artificial solar radiation (UV + visible range) and under dynamic solar illumination taking into account the discontinuities of the solar resource. The results allowed the estimation and comparison of the catalyst’s capabilities and showed its ability to work under natural irradiation. The so developed supported photocatalysts TiO2/Palygorskite exhibited a good activity towards the removal of Orange G (OG) dye from aqueous media under artificial UV and natural solar radiations.

关键词： TiO2 Palygorskite mechanochemical synthesis Nanocomposite Solar Photocatalysis Wastewater Treatment