Synthesis of branched,nano channeled,ultrafine and nano carbon tubes from PET wastes using the arc discharge method

Upcycling polymer wastes into useful, and valuable carbon based materials, is a challenging process. We report a novel catalyst-free and solvent-free technique for the formation of nano channeled ultrafine carbon tubes (NCUFCTs) and multiwalled carbon nanotubes (MWCNTs) from polyethylene terephthalate (PET) wastes, using rotating cathode arc discharge technique. The soot obtain from the anode contains ultrafine and nano-sized solid carbon spheres (SCS) with a mean diameter of 221 nm and 100 nm, respectively, formed at the lower temperature region of the anode where the temperature is approximately 1700 °C. The carbon spheres are converted into long “Y” type branched and non-branched NCUFCTs and MWCNTs at higher temperature regions where the temperature is approximately 2600 °C, with mean diameters of 364 nm and 95 nm, respectively. Soot deposited on the cathode is composed of MWCNTs with a mean diameter of 20 nm and other nanoparticles. The tubular structures present in the anode are longer, bent and often coiled with lesser graphitization compared to the nanotubes in the soot on the cathode.     

Template-free synthesis of inorganic hollow spheres at water/“water-brother”interfaces as Fenton-like reagents for water treatment

This paper reports a template-free method to synthesize a series of inorganic hollow spheres (IHSs) including Cu-1, Cu-2, Ni-1, Ni-2 based on mineralization reactions at water/“water-brother” interfaces. “Water-brother” was defined as a solvent which is miscible with water, such as ethanol and acetone. The water/“water-brother” interfaces are very different from water/oil interfaces. The “water-brother” solvent will usually form a homogenous phase with water. Interestingly, in our method, these interfaces can be formed, observed and utilized to synthesize hollow spheres. Utilizing the unique porous properties of the spheres, their potential application in water treatment was demonstrated by using Cu-1 IHSs as Fenton-like reagents for adsorption and decomposition of Congo Red from aqueous solution. The final adsorption equilibrium was achieved after 30 min with the maximum adsorption capacity of 86.1 mg/g, and 97.3% removal of the dye in 80 min after adsorption equilibrium. The IHSs can be reused as least 5 times after treatment by NaOH. This method is facile and suitable for large-scale production, and shows great potential for watertreatment.     

Photocatalytic activity of ZnO films with micro-grid structure

A layer of zinc oxide (ZnO) micro-grid was deposited on the surface of ZnO film using the DC reactive magnetron sputtering method and the micro-sphere lithography technique on glass substrates. Samples of this layer were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and ultraviolet-visible light spectroscopy. X-ray diffraction showed the high crystallinity of ZnO film and the regular arrangement of the micro-grid. The microgrid ZnO has a lower specular reflection and a higher diffuse reflection, allowing incident light to reflect two or three times to enhance the usage of light. Photocatalytic degradation experiments on methylene blue using both ZnO micro-grid and ordinary film showed that the ZnO micro-grid has better photo-catalytic properties than ordinary film. The ZnO micro-grid enhanced the photocatalytic efficiency of ZnO film by 28% with a degradation time of 300 min.     

Morphology of single inhalable particle in the air polluted city of Shijiazhuang, China

In the typical air polluted city of Shijiazhuang,single inhalable particle samples in non-heating period,heating pened,dust storm days,and snowy days were collected and detected by SEM/EDS(scanning electron microscopy and energy dispersive X-ray spectrometry).The particle morphology was characterized by the 6 shape clusters,which areirregular square,agglomerate,sphere,floccule,column or stick,and unknown,by quantitative order.The irregular square particles are common in all kinds of samples;sphere particles are more,and column or stick are less in winter samples;in the wet deposit samples,agglomerate and floccule particles are not found.The surface of most particles is coarse with fractal edge,which can provide suitable chemical reaction bed in the polluted atmospheric environment.New formed calcium crystal is found to demonstrate the existence of neutralized reaction,explaining the reason for the high SO2 emission and low acid rain frequency in Shijiazhuang.The three sorts of surface patterns of spheres are smooth,semi-smooth,and coarse,corresponding to the element of Si-dominant,Si-Al-dominant,and Fe-dominant.The soot particle is present as floccule with average size around 10 μm,considerably larger than the former reported results,but wrapped or captured with other fine particles to make its appearance unique and enhance its toxicity potentially.The new formed calcium crystal,the 3 sorts of sphere surface patterns,and the unique soot appearance represent the single inhalable particle's morphology characteristics in Shijiazhuang City.     

包埋型SiO2空心球对轻烃的吸附特性

为了研究二氧化硅空心球对轻烃的吸附特性,将二氧化硅空心球置于微孔滤膜和耐油垫圈构成的固定化吸附床中,在相同实验条件下对五种轻烃（正戊烷、正己烷、正庚烷、正辛烷、正壬烷）的吸附性能进行固定床吸附实验,且将实验结果与吸附质的物性参数关联分析。结果表明：不同轻烃在二氧化硅空心球上的吸附容量及穿透时间均为：正壬烷 > 正辛烷 > 正庚烷 > 正己烷 > 正戊烷;同种轻烃在3种二氧化硅空心球（N0、N和N3）的吸附量及穿透时间均为：N3 > N1 > N0。二氧化硅空心球对轻烃的饱和吸附量与吸附质的分子量、沸点、密度呈正线性关系,与饱和蒸汽压成反比关系;轻烃在3种二氧化硅空心球上的吸附能大小均为：正壬烷 > 正辛烷 > 正庚烷 > 正己烷 > 正戊烷。     

Environmental economic,political and ethical integration in a common decision-making framework

This article develops a decision-making framework for environmental management that integrates technical, economic, political and legal, and ethical decision levels. It attempts to show how these decision levels can be ordained, integrated and interconnected and postulates a hierarchic concentric sphere system that proposes an environmental management model for long-term solutions. This model can be used as a check list for environmental management decision-making and also as a guide for environmental conflict resolution where environmental problems necessitate several levels of decision making. It integrates various environmental ethical positions and evaluates political decisions into a comprehensive, broadly applicable multidisciplinary approach. The objective of this decision-making model is to interconnect into a simplified sequence different levels of environmental management processes in order to account for sustainability, efficacy, efficiency and the acceptability of environmental management processes in the long term. This is done by observing when an environmental problem needs to be solved within a certain sphere of solutions and when it requires wider frameworks, how these can be established and how this process proves that solidarity is the widest and most reasonable sphere.     

Synthesis and enhanced visible-light responsive of C,N,S-tridoped TiO2 hollow spheres

C,N,S-tridoped TiO2 hollow spheres （labeled as C,N,S-THs） were synthesized using carbon spheres as template and C,N,S-tridoped TiO2 nanoparticles as building blocks. The structure and physicochemical properties of the catalysts were characterized by X- ray diffraction （XRD）, scanning electron microscopy （SEM）, UV-Vis diffuse reflectance spectrum （DRS）, N2 adsorption-desorption isotherms, X-ray photoelectron spectroscopy （XPS） and Photoluminescence emission spectroscopy （PL）. The results showed that the hollow spheres had average diameter of about 200 nm and the shell thickness was about 20 nm. The tridoped TiO2 hollow spheres exhibited strong absorption in the visible-light region. C,N,S-tridoped could narrow the band gap of the THs by mixing the orbit O 2p with C 2p, N 2p and S 3p orbits and shift its optical response from ultraviolet （UV） to the visible-light region. PL analysis indicated that the electron-hole recombination rate of TiO2 hollow spheres had been effectively inhibited when doped with C, N and S elements. The photocatalytic activities of the samples were evaluated for the degradation of X-3B （Reactive Brilliant Red dye, C.I. Reactive Red 2） aqueous solution under visible-light （λ 〉 420 nm） irradiation. It was found that the C,N,S-tridoped TiO2 hollow spheres indicated higher photocatalytic activity than commercial P25 and the undoped counterpart photocatalyst.     

纳米TiO2花式分层微球的合成及其对Pb（Ⅱ）的吸附性能

利用仿生合成的方法,以甘氨酸为模板剂、钛酸正四丁酯作钛源,水热合成一种新型纳米TiO2花式微球,并对其进行了表征。通过考察pH值、温度和Pb（Ⅱ）溶液的初始浓度对吸附效果的影响,研究了TiO2花式微球对水溶液中Pb（Ⅱ）的吸附性能及其吸附动力学特性。结果表明,纳米TiO2花式微球直径约2Ixm,平均孔径约56nm,比表面积约是270．3m。／g;当pH值为4．0时TiO2花式微球对溶液中Pb（Ⅱ）吸附率达到最高,210min时基本达到吸附平衡,20、30和40qE的最大吸附量分别为75．64、76．34和77．52mg／g。吸附过程遵循准二级速率方程,与Langmuir等温式拟合更好。     

高锰酸钾改性球形中孔炭的甲醛吸附性能

采用球形中孔炭为载体,通过浸渍法担载高锰酸钾（KMnO4）制备高容量甲醛吸附剂。通过低温氮气吸附法、扫描电镜(SEM)、X射线光电子能谱(XPS)表征了球形中孔炭的孔结构及表面化学,并采用固定床测试了相应的球形中孔炭的动态甲醛吸附性能。实验结果表明：经过KMnO4浸渍改性后,球形中孔炭保持良好的球形度,并保留一定的比表面积和孔容,有利于甲醛的扩散以及甲醛与吸附活性位的接触;同时,表面C—O、C=O等含氧官能团数量增加,有效提高了甲醛的吸附性能。在KMnO4浓度为30%时性能最佳,吸附穿透容量和饱和容量分别为30.55 mg·g-1和66.04 mg·g-1,是未改性球形中孔炭的5.2倍和3.4倍。因此,KMnO4改性是提升球形中孔炭甲醛吸附性能的有效手段。