可回收Fe3O4@SiO2-Ag磁性纳米微球对染料污染物的快速脱色处理

介绍了一种采用无毒廉价的前驱物制备Fe₃O₄@SiO₂-Ag磁性纳米微球的快捷方法,制备的Fe₃O₄@SiO₂-Ag纳米微球在NaBH₄存在下可以催化还原染料污染物.实验结果表明,Fe₃O₄@SiO₂-Ag磁性纳米粒子保持了Ag纳米粒子和Fe₃O₄纳米粒子的双重优点,不仅对染料罗丹明B和曙红Y具有良好的催化还原效率,而且可以在外加磁场作用下从溶液中快速有效的分离.催化还原反应速率与反应温度及Fe₃O₄@SiO₂-Ag催化剂用量有关,反应体系中表面活性剂和无机盐(Na₂SO₄)的存在也会影响催化剂的催化活性.该Fe₃O₄@SiO₂-Ag磁性纳米粒子在工业染料污染物处理方面具有应用前景.     

Preparation and characterization of rapid magnetic recyclable Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@SiO<Subscript>2</Subscript>@TiO<Subscript>2</Subscript>–Sn photocatalyst

Effective procedure to synthesize Fe₃O₄@SiO₂@TiO₂–Sn magnetically separable photocatalyst by a combination of co-precipitation, sol–gel and photodeposition methods was introduced. Products were characterized by XRD, SEM, VSM, EDS, DRS, TEM, ICP-OES and IR techniques. The dimensions of catalyst particle size were evaluated by scanning electron microscopy, and results approved nanoscale size for product. In addition, studying the magnetic nature by VSM analysis showed superparamagnetic properties for all samples. XRD pattern indicates that TiO₂ coated on Fe₃O₄@SiO₂ core well crystallized at 400 °C in anatase phase. Synthesized photocatalyst shows good photocatalytic performance in decolorization of rhodamine B aqueous solution. The composite nanoparticles showed high recycling efficiency and stability over five separation cycles.     

Preparation of novel hybrid nanomaterials based on LaFeO3 and phosphotungstic acid as a highly efficient magnetic photocatalyst for the degradation of methylene blue dye solution

Novel magnetic hybrid nanomaterials 1 (LaFeO₃.Fe₃O₄@SiO₂-NH₂/PW₁₂) were synthesized by supporting phosphotungstic acid (H₃PW₁₂O₄₀; PW₁₂) on LaFeO₃.Fe₃O₄ nanomaterials through sono-assisted method. The synthesized nanomaterials were fully characterized by using FT-IR, XRD, UV–vis, BET-BJH, VSM, SEM, and TEM analyses. FT-IR, XRD, and UV–vis confirmed successful synthesis of nanomaterials. The SEM and TEM images revealed spherical morphology with core-shell structure for hybrid nanomaterials 1 . VSM results confirmed the magnetic property of hybrid nanomaterials 1 and suggested it as easily recyclable photocatalyst for removal of organic dyes from aqueous solution. The photocatalytic activity of hybrid nanomaterials 1 has been studied over the degradation of methylene blue (MB) and methyl orange (MO) solution under UV–vis light irradiation. Importantly the hybrid nanomaterials 1 showed outstanding degradation efficiency for MB solution in comparison with bare LaFeO₃.Fe₃O₄ and PW₁₂. The photocatalytic activity was enhanced mainly due to the high efficiency in separation of electron–hole pairs induced by the remarkable synergistic effects of LaFeO₃.Fe₃O₄ and PW₁₂ semiconductors. After the photocatalytic reaction, the nanocomposite can be easily separated from the reaction solution and reused several times without loss of its photocatalytic activity. Trapping experiments indicated that hole (h_VB⁺) and ^•OH radicals were the main reactive species for dye degradation in the present photocatalytic system. On the basis of the experimental results and estimated band gaps, the mechanism for the enhanced photocatalytic activity was proposed.     

Fe2O3/ZnO/ZnFe2O4 composites for the efficient photocatalytic degradation of organic dyes under visible light

In this study, novel ternary Fe₂O₃/ZnO/ZnFe₂O₄ (ZFO) composites were successfully prepared through a simple hydrothermal reaction with subsequent thermal treatment. The as-prepared products were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Brunauer-Emmett-Teller (BET) analysis, Barrett-Joyner-Halenda (BJH) measurement, and UV–vis diffuse reflectance spectroscopy (UV–vis DRS). The photocatalytic degradation of rhodamine B (Rh B) under visible light irradiation indicated that the ZFO composites calcined at 500 °C has the best photocatalytic activity (the photocatalytic degradation efficiency can reach up to 95.7% within 60 min) and can maintain a stable photocatalytic degradation efficiency for at least three cycles. In addition, the photocatalytic activity of ZFO composites toward dye decomposition follows the order cationic Rh B > anionic methyl orange. Finally, using different scavengers, superoxide and hydroxyl radicals were identified as the primary active species during the degradation reaction of Rh B.     

Catalytic Properties of TiO<Subscript>2</Subscript>/Fe<Subscript>3</Subscript>O<Subscript>4</Subscript> Nanoparticles in Plasma Chemical Treatment

We proposed here a new process coupling dielectric barrier discharge (DBD) plasma with magnetic photocatalytic material nanoparticles for improving yield in DBD degradation of methyl orange (MO). TiO₂ doped Fe₃O₄ (TiO₂/Fe₃O₄) was prepared by the sol-gel method and used as a new type of magnetic photocatalyst in DBD system. It was found that the introduction of TiO₂/Fe₃O₄ in DBD system could effectively make use of the energy generated in DBD process and improve hydroxyl radical contributed by the main surface Fenton reaction, photocatalytic reaction and catalytic decomposition of dissolved ozone. Most part of MO (88%) was degraded during 30 min at peak voltage of 13 kV and TiO₂/Fe₃O₄ load of 100 mg/L, with a rate constant of 0.0731 min^?1 and a degradation yield of 7.23 g/(kW h). The coupled system showed higher degradation efficiency for MO removal.     

Fe3O4@SiO2@TiO2-Co/rGO磁性光催化剂的合成及其光催化活性研究

采用溶胶-凝胶法和水热法（HTM）合成了Fe₃O₄@SiO₂@TiO₂-Co/rGO复合纳米粒子（磁性光催化剂）,通过X射线衍射、扫描电子显微镜及其能量分散光谱和UV-vis漫反射光谱对产物进行了表征分析.研究了Co掺杂量、溶液pH值、亚甲基蓝（MB）溶液初始浓度以及干扰离子（例如Cl^-、SO₄^2-、CO₃^2-）等因素对MB降解的影响,并对磁性光催化剂的可重复使用性进行了分析.正常实验条件下（pH=7,[MB]=10 mg/L,磁性光催化剂用量=0.1 g/50 mL）,150 min内MB最大去除率达到98.24%.干扰离子影响MB降解次序为CO₃^2- < Cl^- < SO₄^2-,磁性光催化剂重复使用7次MB光降解率仅下降7.07%,新型磁性光催化剂具有良好的MB降解性能和较高的重复使用性能.     

Stepwise construction of Pt decorated oxygen-deficient mesoporous titania microspheres with core-shell structure and magnetic separability for efficient visible-light photocatalysis

Solid photocatalysts with high specific surface area,superior photoactivity and ease of recycling are highly desired in chemical process,water treatment and so on.In this study,a facile stepwise sol-gel coating approach was utilized to synthesize Pt decorated oxygen-deficient mesoporous titania microspheres with core-shell structure and convenient magnetic separability(denoted as Fe_3 O_4@-SiO_2@Pt/mTiO_(2-x)).These photocatalysts consist of magnetic Fe_3 O4 cores,nonporous insulating SiO_2 middle layer and mesoporous anatase TiO_(2-x) shell decorated by Pt nanoparticles(～3.5 nm) through wet impregnation and H_2 reduction.As a result of high activity of oxygen-deficiency of black TiO_(2-x) by H_2 reduction and efficient inhibition of electron-hole recombination by Pt nanoparticles,the rationally designed core-shell Fe_3 O_4@SiO_2@Pt/mTiO_(2-x) photocatalysts exhibit superior photocatalytic performance in rhodamine B(RhB) degradation under visible light irradiation,with more than 98% of RhB degraded within 50 min.These core-shell structured photocatalysts show excellent recyclability under the assistance of magnetic separation with well-retained photocatalytic performance even after running five cycles.This stepwise synthesis method paves the way for the rational design of a high-efficiency recyclable heterogeneous catalyst,including photocatalysts,for various applications.     

可见光照射下SiW12O404-/Resin光催化剂活化可见光照射下SiW12O404-/Resin光催化剂活化H2O2降解染料的研究

将杂多酸(SiW₁₂O₄₀^4-)负载到阴离子交换树脂上, 得到SiW₁₂O₄₀^4-/Resin (SWR)固相光催化剂, 在可见光的照射下, 可以有效地活化H₂O₂降解染料. 以罗丹明B (Rhodamine B, RhB)为模型化合物, 研究了不同条件下RhB的降解动力学, 以及降解过程中其UV-vis光谱及体系的总有机碳(Total Organic Carbon, TOC)变化情况, 结果表明RhB的共轭芳环结构被破坏, 矿化率为24.2%. 其它染料如孔雀绿(Malachite Green, MG)和吖啶橙(Acridine Orange, AO)等也可以被降解和矿化. 催化剂的循环实验表明SWR固相光催化剂易于分离, 并且具有良好的稳定性, 可以重复利用.     

Synthesis and characterization of magnetite nanoparticles for photocatalysis of nitrobenzene

The present work shows the photocatalytic degradation of nitrobenzene (NB) using Fe₃O₄ magnetic nanoparticles (MNP) as a photocatalyst in the presence of UV light. The MNP were synthesized by an ultrasonic-assisted reverse co-precipitation (US-RP) method using FeSO₄, FeCl₃ and NH₄OH as precursors. The prepared nanoparticles were characterized by UV–vis spectroscopy, attenuated total reflectance Fourier transformed infrared spectroscopy (ATR FT-IR), Raman spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Dynamic light scattering (DLS), Zeta potential, Vibrating sample magnetometer (VSM) and Magnetic thermogravimetric analysis (MTGA). The successive decrement in the absorbance at 265 nm shows the effective decrease in NB concentration measured by UV–vis spectroscopy. The reaction intermediates detected by gas chromatography/mass spectrum (GC/MS) were 2-nitrophenol (2-NPh), 3-nitrophenol (3-NPh) and 4-nitrophenol (4-NPh). The prepared MNP showed an optimal NB degradation at an initial pH of 2 and 100 ppm of the photocatalyst.     

可见光驱动Ag3PO4催化降解罗丹明B和甲基橙

采用简易离子交换法制备可见光驱动Ag3PO4光催化剂.通过X射线衍射、场发射扫描电子显微镜、N2吸附-脱附、紫外-可见漫反射光谱及傅里叶变换红外光谱对所制备的Ag3PO4催化剂进行表征.结果表明,在可见光照射下,Ag3PO4催化剂对罗丹明B降解表现出优越的光催化活性,但对甲基橙的降解活性低,这归因于Ag3PO4催化剂对甲基橙分子吸附量低.可见光照Ag3PO4反应体系中,空穴和超氧自由基共同发挥作用导致罗丹明B和甲基橙光催化降解.在罗丹明B的协助作用下,Ag3PO4催化剂对甲基橙的可见光催化降解活性大大增强,这是由于罗丹明B的存在可产生更多的超氧自由基,从而使甲基橙进一步降解.     

Simultaneous formation of platinum‐based nanocatalysts and degradation of dyes at oil/water interface: Comparative morphological and kinetic studies

To decrease the water pollution of textile industries with a large amount of toxic and non‐biodegradable colored dye effluents, an efficient technique is required to safely remove harmful pollutants. In this paper, the reaction between azo dyes and NaBH₄ catalyzed by nanoparticles (NPs) thin films has been studied. We report insitu degradation of methyl orange (MO) and methyl red (MR) by using Pt‐based thin films monitored by UV–Vis spectroscopy. We have synthesized different thin films such as Pt, PtPd, PtFeFe₂O₃, PtNi and PtAu films from Pt organometallic precursor in the MO and MR medium (dye degradation and NPs formation is happened simultaneously) and activity of these films were compared in the complete degradation of MO and MR dyes. Rate constants for the catalyzed reactions have been determined. PtPd NPs thin film has shown the highest rate constant for the degradation of MO and MR within only a few seconds due to its well‐ordered structure. Furthermore, the effect of presence of MO on the morphology of NPs was investigated.     

Comparison of Cadmium Cd2+ and Lead Pb2+ Binding by Fe2O3@SiO2‐EDTA Nanoparticles – Binding Stability and Kinetic Studies

This study describes the synthesis and characterization of ethylenediaminetetraacetic acid (EDTA) functionalized magnetic nanoparticles of 20 nm in size – Fe₃O₄@SiO₂‐EDTA – which were used as a novel magnetic adsorbent for Cd(II) and Pb(II) binding in aqueous medium. These nanoparticles were obtained in two‐stage synthesis: covering by tetraethyl orthosilicate and functionalization with EDTA derivatives. Nanoparticles were characterized using TEM, FT‐IR, and XPS methods. Metal ions were detected under optimized experimental conditions using Differential Pulse Anodic Stripping Voltammetry (DPASV) and Hanging Mercury Drop Electrode (HDME) techniques. We compared the ability of Fe₃O₄@SiO₂‐EDTA to bind cadmium and lead in concentration of 553.9 μg L^?1 and 647.5 μg L^?1, respectively. Obtained results show that the adsorption rate of cadmium binding was very high. The equilibrium for Fe₃O₄@SiO₂‐EDTA‐Cd(II) was reached within 19 min while for the Fe₃O₄@SiO₂‐EDTA‐Pb(II) was reached within 25 minutes. About 2 mg of nanoparticles was enough to bind 87.5 % Cd(II) and 54.1 % Pb(II) content. In the next step the binding capacity of Fe₃O₄@SiO₂‐EDTA nanoparticles was determined. Only 1.265 mg of Fe₃O₄@SiO₂‐EDTA was enough to bind 96.14 % cadmium ions while 5.080 mg of nanoparticles bound 40.83 % lead ions. This phenomenon proves that the studied nanoparticles bind Cd(II) much better than Pb(II). The cadmium ions binding capacity of Fe₃O₄@SiO₂‐EDTA nanoparticles decreased during storage in 0.5 M KCl solution. Two days of Fe₃O₄@SiO₂‐EDTA storage in KCl solution caused the 32 % increase in the amount of nanoparticles required to bind 60 % of cadmium while eight‐days storage caused further increase to 328 %. The performed experiment confirmed that the storage of nanoparticles in solution without any surfactants reduced their binding capacity. The best binding capacity was observed for the nanoparticles prepared directly before the electrochemical measurements.     

Enhancing photocatalytic activity of titanium dioxide through incorporation of MIL‐53(Fe) toward degradation of organic dye

Photocatalytic activity of titanium(IV) oxide (TiO₂) can be enhanced through modification of its surface‐active sites. Here, iron(III) carboxylate [MIL‐53[Fe]]‐incorporated TiO₂ (as MIL‐53(Fe)/TiO₂) was prepared using a hydrothermal method. This material was then calcined at 500°C to obtain a MIL‐53(Fe)‐derived γ‐Fe₂O₃/TiO₂ photocatalyst. A photocatalytic study of MIL‐53(Fe)/TiO₂ and MIL‐53(Fe)‐derived γ‐Fe₂O₃/TiO₂ toward cationic methylene blue (MB) and anionic methyl orange (MO) showed that MIL‐53(Fe)/TiO₂ (0.25 wt%) and MIL‐53(Fe)‐derived γ‐Fe₂O₃/TiO₂ (0.75 wt%) resulted the best degree of dye degradation. The MIL‐53(Fe)‐derived γ‐Fe₂O₃/TiO₂ (0.75 wt%) composite for instance is capable of degrading almost 100% of 20‐ppm MB and MO, respectively, within 6 hr. Photocatalytic degradation of MB and MO was well fitted to the Langmuir‐Hinshelwood pseudo‐first order kinetics model, which indicates physisorption as the key partway that facilitates dye decomposition on the surface of a photocatalyst under UV‐A irradiation. This study provides new insights into the exploration of MILs/TiO₂ materials for the environmental remediation and pollution control.     

Core shell‐structured NiFe2O4@TiO2 nanoparticle‐anchored reduced graphene oxide for rapid degradation of rhodamine B

In this work, the NiFe₂O₄@TiO₂/reduced graphene oxide (RGO) ternary nanocomposites with high saturation magnetization and catalytic efficiency have been synthesized through the following steps. First, graphene oxide was prepared using the modified Hummer's method. Second, the NiFe₂O₄ nanoparticles were successfully prepared using the hydrothermal method. Third, the core shell‐structured NiFe₂O₄@TiO₂/RGO nanocomposite precursors were easily obtained through hydrolysis reaction. The morphology of NiFe₂O₄@TiO₂/RGO nanocomposites was characterized from scanning electron microscope (SEM) and transmission electron microscope (TEM) images. Moreover, the results of X‐ray diffraction (XRD) patterns proved that the TiO₂ coating shell consisted of anatase. The vibrating sample magnetometer (VSM) measurements showed that the saturation magnetization value of NiFe₂O₄@TiO₂/RGO ternary nanocomposites was 25 emu/g. The X‐ray photoelectron spectroscopy (XPS) analysis confirmed that only part of the graphite oxide (GO) was reduced to RGO in the ternary nanocomposite. The degradation experiments proved that NiFe₂O₄@TiO₂/RGO nanocomposite exhibited the high catalytic efficiency and outstanding recyclable performance for rhodamine B (RhB).     

Green,cost‐effective and efficient procedure for Heck and Sonogashira coupling reactions using palladium nanoparticles supported on functionalized Fe3O4@SiO2 by polyvinyl alcohol as a highly active,durable and reusable catalyst

A novel heterogenized organometallic catalyst was synthesized by coordinating palladium with polyvinyl alcohol‐functionalized Fe₃O₄@SiO₂ nanospheres. This novel catalyst was characterized using Fourier transform infrared spectroscopy, X‐ray diffraction, transmission electron microscope, field emission scanning electron microscope, dynamic light scattering, UV–vis spectroscopy, X‐ray photoelectron spectroscopy, energy dispersive X‐ray analysis, thermogravimetric analysis and inductively coupled plasma analysis. The prepared palladium nanoparticles supported on polyvinyl alcohol functionalized Fe₃O₄@SiO₂ nanoparticles were successfully applied as a magnetically recyclable catalyst in Heck and Sonogashira coupling reactions in water. They showed remarkable activity toward aryl halides (I, Br, Cl) using very low palladium loading in excellent yields and demonstrated high TONs (mmol of product per mmol of catalyst). Also, the catalyst could be magnetically separated and reused seven times without any appreciable loss of catalytic activity.     

Synthesis of Bi<Subscript>2</Subscript>O<Subscript>4</Subscript>@TiO<Subscript>2</Subscript> Heterojunction with Enhanced Visible Light Photocatalytic Activity

A novel Bi₂O₄@TiO₂ heterojunction was constructed by a simple two-step method. The charges migration between Bi₂O₄ and TiO₂ via the heterojunction improves the electron/hole separation efficiency. Furthermore, Bi₂O₄@TiO₂ heterostructures exhibit better adsorption capability for methyl orange molecular due to their higher specific surface area than pure Bi₂O₄. As a result, Bi₂O₄@TiO₂ hybrids show an improved visible light photocatalytic activity and photostability for the degradation of methyl orange.     

Preparation of novel magnetic noble metals supramolecular composite for the reduction of organic dyes and nitro aromatics

By considering the exceptional properties of supramolecular, noble metals (NM) and magnetic nanoparticles (NPs), we successfully synthesized a novel magnetic, metals and supramolecular composite. Briefly, the Fe₃O₄@SiO₂ core-shell spheres were first modified with gold (Au) and palladium (Pd) NPs and then with mono-6-thio-β-cyclodextrin (SH-β-CD). The synthesized Fe₃O₄@SiO₂-Au-Pd@SH-β-CD nanocomposite shows a good magnetic response (42.3 emu/g). The nanocomposite showed good performance for the reductive degradation of rhodamine B (RhB) and 4-nitrophenol (4-NP). The calculated rate constant (k) values for the reduction of 4-NP and RhB were 0.062± 0.02 s⁻¹ and 0.027± 0.01 s^−1, respectively. The high catalytical performance was supposed to be due to the host-guest interaction of β-CD and also due to the NM synergic effect. The nanocomposite structural and chemical morphology was investigated by various spectroscopic techniques. Furthermore, the catalyst was recycled six times and it maintains morphology, chemical nature, and high magnetic behavior, as demonstrated by FTIR and TEM analysis of the recycled catalyst. These results demonstrate a very efficient, cost-effective, and recyclable catalyst in the field of catalysis technology development.     

Synthesis and properties of magnetically separable Fe3O4/TiO2/Bi2O3 photocatalysts

The Fe₃O₄/TiO₂/Bi₂O₃ composites were synthesized by a sol–gel method and used as improved photocatalysts for the degradation of methyl orange (MO) under simulated sunlight at room temperature. The as-prepared Fe₃O₄/TiO₂/Bi₂O₃ composites were characterized by X-ray diffraction, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and diffuse reflectance spectroscopy (DRS). TEM analysis reveals that the composite has a core–shell structure and diameters of Fe₃O₄ core is about 200 nm. DRS results reveal that all composites showed red shift in optical absorption. TiO₂, Fe₃O₄, and Bi₂O₃ exist mainly as separate phases in the Fe₃O₄/TiO₂/Bi₂O₃ composites based on XPS analysis. The photocatalytic degradation of MO with the prepared photocatalysts was studied under simulated sunlight illumination. Photocatalytic reactivity test indicated that the removal efficiency of MO with the Fe₃O₄/TiO₂/Bi₂O₃ photocatalyst was higher than that of pure TiO₂ and Fe₃O₄/TiO₂. Recovery rate of Fe₃O₄/TiO₂/Bi₂O₃ photocatalysts achieved 80 % after five times reuse.     

A novel layered bismuth-based photocatalytic material LiBi3O4Cl2 with OH and h+ as the active species for efficient photodegradation applications

Developing new photocatalysts is of significant importance for their potential environmental and energetic applications. Herein, a novel layered bismuth-based photocatalytic material LiBi₃O₄Cl₂ was developed by a simple solid-state reaction. The morphology, microstructures and optical properties were investigated by XRD, SEM, TEM and DRS. The band gap of LiBi₃O₄Cl₂ has been determined to be 3.35 eV, and its E_CB and E_VB were also estimated. The photocatalytic property of LiBi₃O₄Cl₂ is surveyed by oxidative decomposition of rhodamine B (RhB), methyl orange (MO), methylene blue (MB) and phenol in aqueous solution. The results demonstrated that LiBi₃O₄Cl₂ is an efficient UV light active photocatalyst, which can destroy the contaminants with irradiation. It is also more effective in degrading pollutants than the related layered bismuth-based photocatalyst Bi₄NbO₈Br. The photocatalysis mechanism is detailedly investigated by active species trapping measurement and terephthalic acid photoluminescence probing technique (TA-PL). It revealed that powerful hydroxyl radicals (OH) and photogenerated holes (h⁺) are the two main active species and are responsible for the efficient degradation process. This study provides a new layered bismuth-based photocatalytic material for environmental and energetic applications.     

Preparation of novel palladium nanoparticles supported on magnetic iron oxide and their catalytic application in the synthesis of 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols

Novel Pd nanoparticles were prepared in five successive stages: 1) preparation of the Fe₃O₄ magnetic nanoparticles (Fe₃O₄ MNPs), 2) coating of Fe₃O₄ MNPs with SiO₂ (Fe₃O₄@SiO₂), 3) functionalization of Fe₃O₄@SiO₂ with 3‐chloropropyltrimethoxy‐ silane (CPTMS) ligand (Fe₃O₄@SiO₂@CPTMS), 4) further functionalization with 3,5‐diamino‐1,2,4‐triazole (DAT) ligand (Fe₃O₄@SiO₂@CPTMS @DAT), and 5) the complexation of Fe₃O₄@SiO₂@CPTMS@DAT with PdCl₂ (Fe₃O₄@SiO₂@CPTMS@ DAT@Pd). Then, the obtained Pd nano‐catalyst characterized by different methods such as the elemental analysis (CHN), FT‐IR, XRD, EDX, SEM, TEM, TG‐DTA and VSM. Finally, the Pd catalyst was applied for the synthesis of various 2‐imino‐3‐phenyl‐2,3‐dihydrobenzo[d]oxazol‐5‐ols.