ZnS/还原氧化石墨烯复合材料的制备及光催化性能

水热法一步合成ZnS/还原氧化石墨烯（ZnS/RGO）复合材料,通过XRD、FTIR、Raman、SEM分析溶剂（乙醇、水）对ZnS/RGO复合材料形貌和结构的影响。结果表明,以乙醇为溶剂制备的ZnS颗粒尺寸小、均匀分散在石墨烯片层上,在形成ZnS纳米颗粒的同时将氧化石墨烯（GO）还原成石墨烯。对亚甲基蓝（MB）的光催化结果显示,ZnS/RGO复合材料具有优异的光催化性能,其光催化速率是纯ZnS颗粒的3.7倍,石墨烯作为优良光生电子的传输通道和收集体能够降低光生电子-空穴对的重新结合率,极大提高了ZnS/RGO复合材料的光催化性能。      

二氧化钛/锑掺杂二氧化锡/还原氧化石墨烯复合材料的制备及其光阴极保护性能研究

通过原位生长制备了锑掺杂二氧化锡/还原氧化石墨烯(Sb-SnO₂/RGO)复合材料,再通过水热法生长TiO₂制备了TiO₂/Sb-SnO₂/RGO复合材料。采用X射线衍射、扫描电镜、紫外-可见光、荧光光谱和光电化学等技术对材料的晶体结构、形貌、光吸收特性和电子复合情况进行了表征。结果表明:TiO₂与Sb-SnO₂形成了异质结构,扩大了复合材料的光响应范围,RGO的引入增强了复合材料在可见光区的响应,并提高了电子迁移速率。与TiO₂相比,TiO₂/Sb-SnO₂/RGO复合材料具有更佳的光阴极保护性能。     

还原氧化石墨烯/SnS_2纳米复合物的制备与可见光光催化性能

以氧化石墨烯(GO)和SnCl_4·5H_2O为前驱体,通过水热法制备了SnS_2/还原氧化石墨烯(RGO)复合材料。用X射线衍射(XRD)、扫描电镜(SEM)、拉曼光谱和紫外-可见(UV-Vis)吸收光谱表征了所制备的样品。在可见光(λ≥420nm)光照下光催化降解甲基橙水溶液来检测SnS_2/RGO复合物的光催化活性。结果表明:所制备的SnS_2/RGO复合物表现出增强的可见光光催化活性,其中,含1%(wt,质量分数,下同)石墨烯的复合光催化剂活性最好。SnS_2/RGO复合物光催化活性的增强是由于石墨烯是优秀的电子受体和传输体,它减少了光生载流子的复合,从而提高了光催化活性。     

CdS/CeO_2/还原氧化石墨烯复合材料的制备及其光阴极保护材料性能

以水热法合成棒状CeO_2/石墨烯载体材料,成功在载体上负载CdS纳米粒子得到CdS/CeO_2/还原氧化石墨烯(CdS/CeO_2/RGO)多级结构复合材料。采用透射电镜、X射线衍射仪和拉曼光谱等手段表征材料的结构,探究了该复合材料对304SS的光致阴极保护性能。结果表明:在可见光照射下,与CdS和CdS/RGO相比,CdS/CeO_2/RGO复合材料的光生电子与空穴更易分离,有着更好的光致阴极保护效果,且CeO_2具备存储电子能力,可见光光源关闭后,CeO_2仍能向304SS注入电子,从而在黑暗中对304SS起到持续的阴极保护作用。     

介孔RGO/TiO2复合光催化材料的制备及光催化性能

采用溶胶-凝胶法, 以氧化石墨烯(GO)、钛酸四丁酯(TBT)为原料, 聚乙烯吡咯烷酮(PVP)为结构引导剂, 柠檬酸为水解抑制剂和表面活性剂原位合成不同GO含量的介孔氧化石墨烯/二氧化钛复合材料(GO/TiO₂), 再经过紫外灯辐照还原获得介孔还原氧化石墨烯/二氧化钛复合材料(RGO/TiO₂)。通过X射线衍射(XRD)、透射电镜(TEM)、比表面积(BET)、紫外-可见漫反射(UV-Vis DRS)和荧光光谱(PL)对样品进行分析表征, 研究了RGO/TiO₂的形貌、孔径分布情况, RGO的引入对光生电子-空穴对寿命、吸附性能、光催化性能的影响。分别在紫外光和太阳光条件下评价了复合材料的光催化性能, 并在紫外光条件下, 对催化剂进行了多次回收循环测试。测试结果表明: TiO₂均匀地生长于RGO表面, RGO/TiO₂为介孔材料; RGO的引入可以有效地抑制光催化剂中光生-电子空穴对的复合, 提高吸附性能和光催化性能, 7wt%RGO/TiO₂显示出对甲基橙的最佳吸附效果; 5wt%RGO/TiO₂对甲基橙具有最佳光催化效果和稳定的催化活性, 经过4次循环后, 紫外光照50 min, 对甲基橙的降解率仍能达到首次降解效率的90%以上。     

溶剂热法制备Fe_3O_4/氧化石墨烯复合材料及其性能研究

以氧化石墨和二茂铁为原料,采用溶剂热法原位一步合成了Fe3O4/还原氧化石墨烯(Fe3O4/RGO)复合物,通过X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、透射电镜(TEM)、振动样品磁强计(VSM)、循环伏安测试等手段对复合材料的形貌、结构、磁性能和电化学性能进行了表征。结果表明,该方法具有简单、可控的优点,通过调变前驱物中氧化石墨和二茂铁的比例,可以控制复合物中Fe3O4纳米粒子的负载量。所制备Fe3O4/RGO复合材料由平均粒径约20nm的Fe3O4纳米颗粒高度分散在还原氧化石墨烯片层上组成,具有较好的超顺磁性,电化学稳定性和良好的倍率性能。     

二次掺杂制备聚苯胺/石墨烯/碳纳米管复合材料及其防腐性能EI北大核心CSCD

在高氯酸体系中通过原位聚合将苯胺(ANI)单体分别与还原氧化石墨烯(RGO)、碳纳米管(CNTs)制备了一次掺杂态产物PANI/RGO和PANI/CNTs,产物分别经氨水解掺杂后,在高氯酸体系中经二次掺杂制备得到二次掺杂态聚苯胺/石墨烯/碳纳米管(Redoped PANI/RGO/CNTs)复合材料。通过扫描电镜、透射电镜、傅里叶变换红外光谱和紫外光谱对其不同产物形貌和结构进行表征,通过电化学工作站测试了不同产物在3.5%NaCl溶液的防腐蚀性能。结果表明,在RGO与ANI质量比为1:20、CNTs与ANI质量比为1:20时,二次掺杂态产物中聚苯胺纳米纤维可分别在RGO和CNTs上均匀生长并形成网状结构,纤维长度达到850 nm,形貌均一,其防腐蚀性能最优异,缓蚀效率可达81.79%。通过二次掺杂将PANI/RGO和PANI/CNTs复合制备Redoped PANI/RGO/CNTs材料,可有效避免石墨烯和碳纳米管在制备复合材料过程中的团聚,得到结构规整、防腐性能更优异的复合材料。     

SnO2/还原氧化石墨烯/聚吡咯三元复合物的合成及其电化学电容性能

采用两步法制备出均匀分散的SnO2/还原氧化石墨烯(SnO2/RGO)二元复合物,再以二元复合物为模板,通过化学氧化法聚合吡咯(Py)单体,制备出SnO2/还原氧化石墨烯/聚吡咯(SnO2/RGO/PPy)三元复合材料。利用红外光谱(FTIR)、X射线衍射(XRD)和场发射扫描电镜(FESEM)对复合材料结构和形貌进行物性表征,利用循环伏安、恒电流充放电和交流阻抗对复合材料进行电化学性能研究,并讨论了不同含量的PPy对复合材料的结构和性能的影响。结果表明,所合成的三元复合材料的比电容随PPy含量的增加而增大,最大达到305.3F/g。三元复合物电容性能增强源于SnO2、RGO与PPy三者的相互协同作用,以及材料层状结构和大的比表面积。     

还原剂对Ni(OH)_2/还原氧化石墨烯复合材料结构及电化学性能的影响

为研究还原剂对Ni(OH)_2/还原氧化石墨烯(RGO)复合材料结构及电化学性能的影响,首先以氧化石墨烯(GO)和硝酸镍作前驱体,采用水热法制备了Ni(OH)_2/RGO复合材料;然后,利用XRD、SEM和Raman光谱仪表征了复合材料的结构和形貌,并采用循环伏安法、恒流充放电曲线和电化学阻抗谱研究了复合材料的电化学性能。结果表明:以(NH2)2CSO2作还原剂时,制备的β-Ni(OH)_2/RGO复合材料为RGO纳米片与Ni(OH)_2纳米片相互插层的结构;在电解液(6mol/L KOH溶液)中,0.2C放电倍率时β-Ni(OH)_2/RGO复合材料的比容量高达341.0mAh/g,10.0C放电倍率为时复合材料的比容量为242.2mAh/g,仍能保持β-Ni(OH)_2理论比容量的83.8%。所得结论表明制备的Ni(OH)_2/RGO复合材料显现出良好的电化学性能。     

石墨烯/聚苯胺/四氧化三锰纳米复合材料的制备

成功制备了石墨烯/聚苯胺/四氧化三锰(RGO/PANI/Mn_3O_4)纳米复合材料。首先,以过硫酸铵(APS)为氧化剂,在氧化石墨烯(GO)片层上氧化聚合苯胺单体,制备氧化石墨烯/聚苯胺(GO/PANI),再通过水热法将GO还原并热解Mn(Ac)_2·4H_2O从而制得RGO/PANI/Mn_3O_4复合材料。形貌和结构表征结果表明Mn_3O_4纳米颗粒均匀生长在以PANI为导电连接层的RGO片层上。     

Growth of Cu2O nanoparticle on reduced graphene sheets with high photocatalytic activity for degradation of Rhodamine B

Cu₂O–reduced graphene oxide (RGO) nanocomposite was synthesized by a simple one-pot solvothermal method. The morphology and properties of Cu₂O/RGO nanocomposites were characterized by scanning electron microscope, Raman spectroscopy, X-ray diffraction, photoluminescence spectroscopy, and X-ray photoelectron spectroscopy. The photocatalytic activities of the as-prepared nanocomposites were investigated by photodegrading Rhodamine B under visible light. Results show that Cu₂O/RGO nanocomposites exhibited a remarkably enhanced photocatalytic efficiency compared with pure Cu₂O nanoparticles and commercial P25. Moreover, we found that the content of graphene oxide introduced into composite material was a crucial factor for its improved photocatalytic performance.     

Graphene-SnO(2) composites for highly efficient photocatalytic degradation of methylene blue under sunlight

Graphene sheets decorated with SnO(2) nanoparticles (RGO-SnO(2)) were prepared via a redox reaction between graphene oxide (GO) and SnCl(2). Graphene oxide (GO) was reduced to graphene (RGO) and Sn(2+) was oxidized to SnO(2) during the redox reaction, leading to a homogeneous distribution of SnO(2) nanoparticles on RGO sheets. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show uniform distribution of the nanoparticles on the RGO surface and high-resolution transmission electron microscopy (HRTEM) shows an average particle size of 3-5?nm. The RGO-SnO(2) composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO(2) nanoparticles. This result leads us to believe that the RGO-SnO(2) composite could be used in catalytic photodegradation of other organic dyes.     

Cu/还原氧化石墨烯光催化复合材料的制备及其光催化性能

以乙酸铜和氧化石墨烯（GO）为原料,抗坏血酸为还原剂,采用液相化学法合成Cu/还原氧化石墨烯（Cu/RGO）复合材料。通过XRD、SEM、TEM、FTIR和Raman对材料结构及形貌进行表征,并考察Cu/RGO复合材料在H₂O₂辅助作用下对亚甲基蓝（MB）的光催化作用。结果表明：Cu颗粒均匀分布在RGO片层上,相比于纯Cu,Cu/RGO复合材料的光催化性能明显提高,Cu/RGO复合材料用量为0.06 g/L时,对MB显示出最佳的催化效果,200 min内脱色率达到了92.5%,经过5次循环后脱色率仍有88.0%以上。     

Facile synthesis of novel ZnO/RGO hybrid nanocomposites with enhanced catalytic performance for visible-light-driven photodegradation of metronidazole

This study reported the first-time fabrication of uniform ZnO nanoclusters through a facile carbon nanosphere template-assisted approach, where the synthesized ZnO products were further decorated with the prepared reduced graphene oxide (RGO) to form novel ZnO/RGO nanocomposites. The as-synthesized materials were well characterized with the aid of various techniques, before they were used as photocatalysts for the degradation of metronidazole in the aqueous environment. Accordingly, the photocatalytic activity of the ZnO nanoclusters could be enhanced by coupling with RGO, where a large improvement (approx. 32.4% increase compared with pure ZnO) in the visible-light-driven degradation of metronidazole was observed on the prepared ZnO/RGO hybrid nanocomposites. Such study may provide insight into the usage of the ZnO/RGO composite in addressing broader environmental issues. The synthetic route employed in this work might also be extended to a useful technique for the preparation of assemblies of other materials based on nanoscale templates via easily-manipulated solution methods.     

石墨烯/纳米TiO_2复合材料的制备及光催化还原性能

为探索超声辅助下利用紫外光及耦合热还原工艺制备RGO/纳米TiO_2复合材料的方法,并对其在缺氧水体中的光催化还原特性进行研究,首先,以鳞片石墨为原料,采用改进的Hummers法制备了氧化石墨烯(GO),进而通过超声/紫外光还原工艺制备了还原氧化石墨烯(RGO);然后,以钛酸丁脂和RGO为前驱物,采用溶胶-凝胶法并在氮气保护下高温加热制备了RGO/纳米TiO_2复合光催化材料;接着,利用FTIR、XRD、BET及紫外-可见光谱等对RGO/纳米TiO_2复合材料进行了结构性能表征;最后,以2,4-二氯苯氧乙酸(2,4-D)为探针物,研究了RGO/纳米TiO_2在缺氧水体中的光催化特性与2,4-D降解机制。结果表明:采用低温氧化Hummers法制备的GO六碳环上生成的活性基团较少,采用超声/紫外光还原工艺及耦合高温热还原工艺可使环状结构得到良好的修复;所制备的RGO/纳米TiO_2复合材料具有良好的2,4-D降解能力,在缺氧状态下,2,4-D主要发生光催化还原反应,脱除苯环上的氯,产生氯酚、邻苯三酚及间苯三酚等中间产物,部分2,4-D被氧化降解生成CO_2和H_2O。制备的RGO/纳米TiO_2复合材料具有良好的光催化还原性能。     

Titania-reduced graphene oxide nanocomposite as a promising visible light-active photocatalyst for continuous degradation of VVOC in air purification process

Titania-reduced graphene oxide nanocomposites have been prepared through facile hydrothermal method by a reaction between P25 as TiO₂ source and graphene oxide. Reduction of graphene oxide and its reaction with P25 nanoparticles were achieved simultaneously at high temperature and pressure during the hydrothermal process with the minimum organic solvents. Chemical bonds, crystalline structure, morphology, porosity and light absorption of composites along with their photocatalytic activity under UV and visible light irradiation were investigated. Transmission electron microscopy images showed that P25 nanoparticles, with diameters about 25 nm, were dispersed on the sheets of reduced graphene oxide (RGO) homogeneously. A stronger interaction between P25 and RGO provided a red shift about 20 nm in the absorption edge of the composites. To set up a continuous tubular reactor made from thin layer of the prepared material, composite films were coated on the external surface of a steel tube to make an annular reactor. The reactor was equipped with UV or visible light sources to investigate the photocatalytic activity of the prepared composites in a continuous air flow contaminated with specified amount of acetaldehyde as a VVOC (very volatile organic compound) model molecule. Degradation efficiency of P25–RGO with 0.5 wt% RGO was significantly high under visible light irradiation, and about 70% conversion was observed using an air flow at normal conditions with specific flow rate of 17 ml min^?1 and 500 ppm acetaldehyde, by 30 mg of the coated composite in the reactor. Composites with low amount of RGO would be an appropriate photosensitizer and electron acceptor to suppress the recombination of photogenerated electron–hole pairs to enhance the photocatalytic performance.     

Size-controlled BiOCl–RGO composites having enhanced photodegradative properties

Visible light-active bismuth oxychloride–reduced graphene oxide (BiOCl–RGO) composite photocatalysts were synthesised using a hydrothermal method at low temperature, and at a low cost. This approach reduced the recombination of electron–hole pairs and thereby provided more efficient photocatalysts. The size of BiOCl structure was controlled by polyvinylpyrrolidone (PVP) addition. Furthermore, formation of nanosized BiOCl sheets and BiOCl–RGO composites were confirmed by X-ray diffraction, X-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. Fabricated BiOCl–RGO composite with PVP exhibited better photocatalytic activity than pure BiOCl grown with and without PVP towards degradation of Rhodamine B (RhB). It was found that the composite photocatalyst degrades RhB completely within 310 min as compared with several hours for pure BiOCl. The improved photocatalytic performance of BiOCl–RGO composite was attributed to its high specific surface area (22.074 m² g^?1 and existence of polar surfaces, compared with 9.831 m² g^?1 for pure BiOCl). The analyses indicated that RGO helped to reduce recombination losses and improve electron transport. It also showed that presence of polar surfaces improved photocatalytic activity of BiOCl. Hence, BiOCl–RGO composite is a promising catalyst for the degradation of organic pollutants under visible light and could be used in applications such as water purification devices.     

Excellent photocatalytic performance under visible-light irradiation of ZnS/rGO nanocomposites synthesized by a green method

ZnS/graphene nanocomposites with different graphene concentrations (5, 10 and 15 wt.%) were synthesized using L-cysteine as surfactant and graphene oxide (GO) powders as graphene source. Excellent performance for nanocomposites to remove methylene blue (MB) dye and hexavalent chromium (Cr(VI)) under visible-light illumination was revealed. TEM images showed that ZnS NPs were decorated on GO sheets and the GO caused a significant decrease in the ZnS diameter size. XRD patterns, XPS and FTIR spectroscopy results indicated that GO sheets changed into reduced graphene oxide (rGO) during the synthesis process. Photocurrent measurements under a visiblelight source indicated a good chemical reaction between ZnS NPs and rGO sheets.