BiOBr nanosheets coupling with biomass carbon derived from locust leaves for enhanced photocatalytic degradation of rhodamine B

A series of BiOBr@biomass carbon derived from locust leaves materials(BiOBr@BC)were fabricated and the photocatalytic property was investigated for photocatalytic degradation of rhodamine B(RhB)under visible light.The morphology,structure and photoelectrochemical properties of the photocatalysts were characterized by means of SEM,TEM,XRD,XPS,FT-IR,BET,PL,UV-vis/DRS,and EIS techniques.The results showed that the introduction of BC significantly enhanced the photocatalytic activity.When the content of biomass carbon(BC)in a composite is 3%(based on the mass of BiOBr),the obtained BiOBr@BC-3 exhibits excellent photocatalytic activity,degrading 99%of RhB within 20 min.The excellent degradation efficiency after the introduction of BC can be attributed to the enhanced visible light absorption,narrower band gap,and fast electron-hole pair separation rate.The photocatalytic mechanism on the degradation of RhB was illustrated based on the radicals'trapping experiments and semiconductor energy band position.The proposed material is expected to be of significant application value in the field of wastewater treatment.

Construction and photocatalytic properties toward rhodamine B of CdS/Fe_(3)O_(4) heterojunction

A simple two-step hydrothermal method synthesized four different CdS/Fe_(3)O_(4)photocatalysts with varying ratios of mass of CdS to Fe_(3)O_(4).The composition and morphology of the prepared samples were investigated using X-ray diffraction(XRD),Raman spectrum,X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),and transmission electron microscopy(TEM).Solid UV reflectance spectra testing found that CdS/Fe_(3)O_(4)nanocomposites had good light absorption throughout the spectral range,promoting their photocatalytic properties.Under visible light irradiation,CdS/Fe_(3)O_(4)(2∶5)with a mass ratio of 2∶5 exhibited excellent photocatalytic perfor-mance,with a degradation rate of 98.8%for rhodamine B.Furthermore,after five cycles of photocatalytic degrada-tion reaction,the rhodamine B degradation rate remained at 96.2%,indicating that the photocatalysts have good pho-tocatalytic stability.

重金属捕获剂EDTC协同处理EDTA-Cu/RhB的去除特性

以乙二胺(C_(2)H_(8)N_(2))和二硫化碳(CS_(2))为原料,采用共混法合成重金属捕集剂N,N-双(二硫代羧基)乙二胺(EDTC)。考察物料配比、投加顺序、溶液pH、时间和温度等因素对EDTC作为药剂协同处理废水中络合态铜(EDTA-Cu)和染料罗丹明B(Rhodamine B,RhB)双组分体系的去除特性影响,并与单组分EDTA-Cu和RhB体系的去除效果进行对比。结果表明:常温下,于180mg/L的EDTA-Cu和1800mg/L的RhB水体中投加1.3g/L EDTC时,EDTA-Cu和RhB的去除量分别高达150mg/g和850mg/g,水体pH在2~10范围内运行稳定。与EDTC处理水体中单组分EDTA-Cu和RhB的去除效果相比,EDTC可有效同时去除水体中的络合铜和RhB,且具有协同效应。因此,EDTC可作为水处理药剂应用于协同处理带有络合态金属和染料的复杂废水。

Eu掺杂ZnO多孔片状材料的制备及其降解印刷染料RhB

采用常温络合-水解法构筑Eu掺杂Zn O多孔片状材料。通过SEM、TEM、XRD、EDS等表征手段证明稀土元素Eu成功掺杂到Zn O之中,Eu-Zn O的形貌为多孔片状结构。研究了Eu-Zn O多孔片状材料对染料的光催化性能。结果表明:该材料对Rh B具有较好的降解效率,降解效率高达99.2%,循环稳定性能高达98.3%,远大于商用Zn O的76.2%的降解效率和82.3%的循环稳定性能,由以上数据说明Eu-Zn O具有很好的光催化降解效率和循环稳定性能。其优异的光催化性能归因于稀土元素Eu掺杂和多孔片状结构。

Fabrication of a monoclinic/hexagonal junction in WO_3 and its enhanced photocatalytic degradation of rhodamine B

A series of WO3 samples with different crystalline phases were prepared by the thermal decomposition method from ammonium tungstate hydrate.X-ray diffraction（XRD）,scanning electron microscopy（SEM）,high-resolution transmission electron microscopy（HRTEM）,X-ray photoelectron spectroscopy,and N2 adsorption-desorption were used to characterize the crystalline phase,morphology,particle size,chemical composition,and surface area of the WO3 samples.The formation of hexagonal（h-WO3） and monoclinic（m-WO3） crystal structures of WO3 at different temperatures or different times was confirmed by XRD.m-WO3 is formed at 600 ℃,while m-WO3 starts to transform into h-WO3 at 800℃.However,h-WO3,which forms at 800℃,may transform into m-WO3 by increasing the calcination temperature to 1000℃.SEM results indicate that m-WO3 particles exhibit a bulky shape with heavy aggregates,while h-WO3 particles exhibit a rod-like shape.Moreover,m-WO3 crystals are sporadically patched on the surface of the h-WO3 rod-like particles,resulting in the exposure of both m-WO3 and h-WO3 on the surface.It is observed that the monoclinic phase（m-WO3）/hexagonal phase（h-WO3） junction was fabricated by tuning the calcination temperature and calcination time.The relative ratios between m-WO3 and h-WO3 in the phase junction can readily be tailored by control of the calcination time.The photocatalytic activities of WO3 with different crystalline phases were evaluated by the photocatalytic degradation of rhodamine B as a model pollutant.A higher photocatalytic activity was observed in the WO3 sample with the m-WO3/h-WO3junction as compared with the sample with only m-WO3.The improvement of photocatalytic activity can be attributed to the reduction of the electron-hole recombination rate owing to the formation of the phase junction,whose presence has been confirmed by HRTEM and photoluminescence spectra.

可见光下Rhodamine B在钴掺杂TiO_2薄膜上的光催化降解

采用溶胶-凝胶法和涂覆成膜技术在钛片上制备了有可见光响应的Co2+掺杂TiO2薄膜(Co-TiO2).应用该薄膜光催化剂在可见光下进行了Rhodamine B(RhB)的光降解研究.结果表明,当Co2+的掺杂摩尔分数为0.02%时,光催化剂对RhB有最佳的光降解效果,而且在降解过程中存在光催化和光敏化的协同效应;同时在酸性体系中光降解RhB比在碱性体系中有较快的速率和较小的最大吸收峰位移,这可能与不同pH下,TiO2表面的荷电状态影响光降解过程有关.Co-TiO2光催化剂的使用,成功地实现了可见光下对RhB的光催化和光敏化协同降解,提高了可见光下RhB的光降解速率.

Ce(Ⅳ)-Rhodamine B-噻枯唑体系化学发光法测定噻枯唑

在酸性介质中,Ce(Ⅳ)可以氧化噻枯唑产生较弱的化学发光,罗丹明B可以显著增强此发光,且增加的发光强度与噻枯唑的质量浓度在一定范围内呈良好的线性关系,由此建立了测定噻枯唑的流动注射化学发光新方法。该法的检出限为12μg/L(3σ),线性范围为30～1 000μg/L,对500μg/L的噻枯唑连续平行测定11次,其相对标准偏差(RSD)为2.4%。用于测定环境水样中和大米中噻枯唑含量,回收率为96.4%～104.1%。

新型泡沫镍模板Ti_(3)C_(2)T_(x)@ZnO复合材料光降解RhB应用研究

工业染料废水的净化对缓解水资源危机至关重要,但传统的金属氧化物半导体光催化降解方法存在成本高、效率低等问题。与之形成鲜明对比的是,MXenes材料因其高比表面积和优秀的导电性,尤其是经过剥离的片状MXenes材料,在光照下展示出了卓越的电荷转移能力,MXenes材料的利用开辟了光催化反应的新途径。特别是,MXenes如Ti_(3)C_(2)T_(x)与传统ZnO相比,在催化效率和稳定性上都有显著提升。本研究将ZnO与Ti_(3)C_(2)T_(x)结合,制备了一种高比表面积的光催化复合材料,既增加了活性位点,也显著提高了光催化效率。通过水热法,成功将单层Ti_(3)C_(2)T_(x)涂覆在泡沫镍上,并在其上生长ZnO纳米棒,制备出高效的光催化降解材料。实验结果表明,性能最优的材料能在100 min内将RhB的降解率提升至97.7%,同时也有效降解了四环素和对氯苯酚。这证明MXenes材料和金属氧化物复合材料在光催化染料降解领域具有巨大的应用潜力。

二维BiOX光催化去除废水中RhB的研究

目的研究二维(2D)卤氧化铋(BiOX,X=Cl,Br,I)对水中罗丹明B(RhB)的去除性能和机理。方法通过溶剂热法合成2D BiOX。借助多种表征手段对BiOX的结构、形貌、光学性质等进行分析;研究紫外-可见光照下2D BiOX对水中RhB的光催化去除性能。结果BiOCl催化作用下,光照180 min后,RhB降解率可达98.8%。过程符合拟一阶反应动力学模型,反应速率常数k为22.9×10^(-3)min^(-1)。以叔丁醇和氯仿为捕获剂时,RhB降解率无明显变化;而以乙二胺四乙酸二钠和重铬酸钾为捕获剂时,RhB降解率显著下降。结论BiOCl的光催化活性高,可归因于其较快的载流子传递速率和较强的氧化还原能力。RhB光催化降解过程中起主要作用的活性物种为h^(+)和e^(-)。

Microwave photocatalytic degradation of Rhodamine B using TiO_2 supported on activated carbon:Mechanism implication

The photocatalytic degradation of Rhodamine B （RhB） was carried out using TiO2 supported on activated carbon （TiO2-AC） under microwave irradiation. Composite catalyst TiO2-AC was prepared and characterized using X-ray diffraction （XRD）, transmission electron microscopy （TEM） and Brunauer-Emmett-Teller （BET）. In the process of microwave-enhanced photocatalysis （MPC）, RhB （30 mg/L） was almost completely decoloured in 10 min, and the mineralization efficiency was 96.0% in 20 min. The reaction rate constant of RhB in MPC using TiO2-AC by pseudo first-order reaction kinetics was 4.16 times of that using Degussa P25. Additionally, according to gas chromatography/mass spectrometry （GC/MS） and liquid chromatography/mass spectrometry （LC/MS） identification, the major intermediates of RhB in MPC included two kinds of N-de-ethylation intermediates （N,N-diethyl-N＇-ethyl-rhodamine （DER））, oxalic acid, malonic acid, snccinic acid, and phthalic acid, maleic acid, 3-nitrobenzoic acid, and so on. The degradation of RhB in MPC was mainly attributed to the destruction of the conjugated structure, and then the intermediates transformed to acid molecules which were mineralized to water and carbon dioxide.

Photocatalytic degradation of Rhodamine B under visible light with Nd-doped titanium dioxide films

Microporous titanium dioxide films were prepared by the sol-gel methods on glass substrates, using tetrabutyl titanate as source material. In order to absorb the visible light and increase the photocatalytic activities, different concentrations of neodymium ions (Nd/Ti molar ratio was 0.5%, 0.7%, 0.9%, and 1.1% respectively) were added into the sol. X-ray diffraction (XRD), X-ray photoelectron spectros-copy (XPS), and atom force microscopy (AFM) were applied to characterize the modified films. A kind of typical textile industry pollutant (Rhodamine B) was used to evaluate the photocatalytic activities of the films under visible light. The results showed that the activities of the films were improved by doping Nd ions into the sol.

Green Oxygenation Degradation of Rhodamine B by Using Activated Molecule Oxygen

Iron(II) tetra-(1,4-dithin)-porphyrazine, (FePz(dtn)4) is able to activate molecule oxygen for oxygenation degradation of rhodamine B (RhB) in an extensive pH region without light excitation. Experiments indicate that the RhB can be degraded nearly 52% in alkaline aqueous solution, bubbling with dioxygen for seven hours in the presence of FePz(dtn)4 and the hydrogen peroxides as an active intermediate were determined by DPD method. The catalyst is recyclable and the catalyst activity was maintained after 10 recycles.

Detection of intermediates in the TiO_2-assisted photodegradation of Rhodamine B under visible light irradiation

The photocatalytic degradation of dye Rhodamine B （RhB） in the presence of TiO2 nanostdpe or P25 under visible light irradiation was investigated. The degradation intermediates were identified using Infrared spectra （IR spectra）, ^1H nuclear magnetic resonance （^1HNMR） spectra, and gas chromatography-mass spectroscopy （GC-MS）. The IR and the ^1HNMR results showed that the large conjugated chromophore structure of RhB was efficiently destroyed under visible light irradiation in both the photocatalytic systems （TiO2 nanostfipe or P25 and Rhodamine B systems）. GC-MS results showed that the main identified intermediates were ethanediotic acid, 1,2-benzenedicarboxylic acid, 4-hydroxy benzoic acid and benzoic acid, which were almost the same in the TiO2 nanostdpes and P25 systems. This work provides a good insight into the reaction pathway（s） for the TiO2-assisted photocatalytic degradation of dye pollutants under visible light irradiation.

Studies on the Recognition Interaction of Rhodamine B and DNA by Voltammetry

The recognition interaction of Rhodamine B(RB) with DNA was studied in a Britton-Robinson (B-R) buffer solution with pH=7.5 at a glassy carbon electrode by electrochemical techniques. RB shows an irreversible oxidation peak at +0.92 V(vs. SCE). After the addition of DNA in the RB solution, the peak current of RB decreased apparently without the shift of the peak potential. The electrochemical parameters such as the charge transfer coefficient α and the electrode reaction rate constant k s of the interaction system were carefully studied. The parameters did not change before and after the addition of DNA, which indicated that an electrochemical non-active complex had been formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly. The binding ratio of RB to DNA was 2∶1 with a binding constant of 2.66×10 9.

Electrochemical oxidation of rhodamine B by PbO_2/Sb-SnO_2/TiO_2 nanotube arrays electrode

A PbO2/Sb-SnO2/TiO2 nanotube array composite electrode was successfully synthesized and its electrochemical oxidation properties were investigated.Field-emission scanning electron microscopy(FE-SEM)and X-ray diffraction(XRD)results showed that the PbO2 coating was composed of anα-PbO2 inner layer and aβ-PbO2 outer layer.Accelerated life measurement indicated that the composite electrode had a lifetime of 815 h.Rhodamine B(RhB)was employed as a model pollutant to analyze the electrocatalytic activity of the electrode.The effects of initial RhB concentration,current density,initial pH,temperature,and chloride ion concentration on the electrochemical oxidation were investigated in detail.Inductively coupled plasma atomic emission spectroscopy(ICP-AES)results suggested that the concentration of leached Pb^2+in the electrolyte during the electrocatalytic oxidation process can be neglected.Finally,the degradation mechanism during the electrocatalytic oxidation process was proposed based on the results of solid-phase micro-extraction-gas chromatography-mass spectrometry(SPME-GC-MS).The high electrocatalytic performance of the composite electrode makes it a promising anode for the treatment of organic pollutants in aqueous solution.

Simultaneous Determination of Fluorescein, Rhodamine 6G and Rhodamine B in Turbid Solution by Polarization Variable-Angle Synchronous Fluorescence Spectrometry

Polarization variable-angle synchronous fluorescence spectrometry was proposed to determine samples in turbid solution. A mixture of fluorescein, rhodamine 6G and rhodamine B was used to evaluate the technique. The background caused by scattering light was decreased remarkably. The limits of detection were 0.6 ng/ml for fluorescein, 2.3 ng/ml for rhodamine 6G and 4.1 ng/ml for rhodamine B, respectively.

Enhanced Photocatalytic Denitrification Rhodamine Bover In2O3/Bi24O31Br10 Nanocomposites under Visible Light Irradiation

A novel In203/Bi24O31Br10 composite photocatalyst, where In2O3 nanoparticleswith the diameter of about 5-10 nm were tightly attached on the surface of Bi24O31Br10 plates, wasprepared by using hydrolysis, impregnation method and post-thermal process. Photocatalyticactivity was evaluated by the degradation of Rhodamine B under the visible light irradiation.Effects of the contents of In203 nanoparticles on the optical property and photocatalytic activity of In203/Bi24O31Br10 composite were also investigated. Compared with neat In203 and Bi24O31Brlomaterials, 15In203/Bi24O31Br10 composite exhibits the best photocatalytic activity owing to theefficient separation of photogenerated electron and hole pairs, which is evidenced byphotoluminence spectra. More than 95% of Rhodamine B solution can be degraded by15In203/Bi24O31Brlo sample in 30 min.

Electrochemical Studies of the Recognition Interaction of Rhodamine B with DNA

The recognition interaction of rhodamine B (RB) with DNA was studied in pH 7.5 Britton-Robinson (B-R) buffer solution by electrochemical techniques. An irreversible oxidation peak at glassy carbon electrode was obtained at +0.92V (vs. SCE). After the addition of DNA into the RB solution, the peak current of RB decreased apparently without the shift of peak potential. The electrochemical parameters such as the charge transfer coefficient a and the electrode reaction standard rate constant ks of RB in the absence and presence of DNA were determined, which did not change, indicating that a non-electroactive complex was formed, so the concentration of RB in the solution decreased and the peak current decreased correspondingly.

Photocatalytic Degradation of Rhodamine B Dye in Wastewater Using Gelatin/CuS/PVA Nanocomposites under Solar Light Irradiation

The crosslinked gelatin/CuS/PVA nanocomposite catalyst prepared using gamma irradiation as initiator was extensively characterized using several techniques including transmission electron microscopy (TEM), UV-Vis spectroscopy, infrared spectroscopy (IR) and X-ray diffraction (XRD). We chose Rhodamine B (RhB) dye as a model contaminant in order to investigate its Photocatalytic activity under solar light irradiation. The effects of pH, catalyst concentration and RhB concentration on degradation reaction were also investigated. Similar to the observed trend for the photocatalytic oxidation of other organic compounds, the efficiency of photocatalytic degradation of RhB tended to decrease with increasing the concentration of RhB. The degradation efficiency of RhB is found to increase as pH is increased up to pH of 10, then starts decreasing at pH values higher than 10. The degradation efficient of RhB is found to increase as the amount of the catalyst dosage increases up to an optimum value of 0.25 g. Increasing the concentrations of photocatalyst beyond 0.25 g was found to decrease the photocatalytic activity of RhB. It was proven that the degradation process of RhB reaction rate obeyed a pseudo-first-order reaction of the catalyst concentration of gelatin/CuS/PVA nanocomposite. The degradation kinetics was found to fit well Langmuir-Hinshelwood rate law. The results obtained showed that after using the catalyst five times repeatedly, the catalyst retained its efficiency and the rate of the degradation process was still above 80%.

Determination of Rhodamine B in Food Using HPLCUV Method

[ Objective] The aim was to establish a method for the determination of Rhodamine B in food by HPLC-UV. [ Metkod] Rhodamine B was extracted with acetone/hexane from food samples. After concentrated and purified by alumina cartridge, the Rhodamine B content in the food was determined by using high performance liquid chromatography with ultraviolet visible detector. [ Result] Within tile concentration range of 0.005 - 2.000 mg/kg, the peak area of Rhodamine B presented good linear relation with the concentration, and the related coefficient was 0.999 98. With high average recovery rate, the detection limit of the method was 0.005 mg/kg[ Concision] It is a fast and accurate method with high sensitivity to detect Rhodamine B in food.