石墨烯负载的钴纳米粒子催化还原4-硝基苯酚

以葡萄糖为碳源、NH4Cl为发泡剂、纳米金属Co为促进葡萄糖石墨化的催化剂,通过一步法制备了Co-石墨烯复合材料,实现了石墨烯的形成和Co纳米粒子原位生长的同步进行。通过XRD、FTIR、XPS、Raman、UV-Vis和TEM对该复合材料的结构与形貌进行了表征。将Co-石墨烯复合材料用于催化还原对硝基苯酚(4-NP)反应。在室温下,使用4 mg催化剂可于8 min内将1.39 mg 4-NP全部还原。复合材料通过简单的磁分离可循环利用,使用5次后,4-NP转化率依然高达86%。     

石墨烯负载钴纳米粒子催化还原4-硝基苯酚

以葡萄糖为碳源、NH4Cl为发泡剂、纳米金属Co为促进葡萄糖石墨化的催化剂,通过一步法制备了Co-石墨烯复合材料,实现了石墨烯的形成和Co纳米粒子原位生长的同步进行。通过XRD、FTIR、XPS、Raman、UV-Vis和TEM对该复合材料的结构与形貌进行了表征。将Co-石墨烯复合材料用于催化还原对硝基苯酚(4-NP)反应。在室温下,使用4 mg催化剂可于8 min内将1.39 mg 4-NP全部还原。复合材料通过简单的磁分离可循环利用,使用5次后,4-NP转化率依然高达86%。     

纳米纤维素负载纳米金的制备及其催化性能研究

以高碘酸钠氧化纳米纤维素(NC)制备得到双醛基纳米纤维素(DNC),并以DNC为还原剂和负载体,制备得到NC负载纳米金催化剂。并通过UV、FT-IR、XRD、XPS及TEM对催化剂合成条件、化学结构、晶型结构、纳米金在纤维素载体表面的价态及大小分布等进行了表征。结果显示金离子90℃下9 h后基本被DNC完全还原为单质金;且纳米金粒子均匀分布在NC上,粒径在40 nm左右。以硼氢化钠还原4-硝基苯酚(4-NP)反应作为模型来研究纳米纤维素负载纳米金的催化性能,研究显示55 min后4-NP转化率可达94%,其催化速率常数为0.073 min~(-1)。     

镍负载二氧化钛/PEI/石墨烯纳米复合催化剂的制备与研究

首先采用改进的Hummers法制备了氧化石墨烯(GO),再以聚乙烯亚胺(PEI)修饰的氧化石墨烯为载体,并以硫酸钛和氯化镍为前驱体,利用水热法在180 ℃下以PEI为交联剂制得镍负载的TiO2/PEI/石墨烯纳米复合催化剂。通过紫外可见分光光度计(UV-vis)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射仪(XRD)等测试手段对催化剂进行了表征。结果表明,Ni-TiO2/PEI/RGO纳米复合催化剂中镍负载TiO2纳米粒子与石墨烯能够均匀复合,并具有较小的晶粒尺寸。以对硝基苯酚(4-NP)为降解目标物,考察了该催化剂在NaBH4存在下还原4-NP的催化活性。结果表明,镍负载的TiO2/PEI/石墨烯纳米复合催化剂具有良好的重复催化活性,其降解率为98%,催化剂重复使用10次后,降解率仍能保持90%以上。     

Ag/rGO纳米粒子的合成及其催化还原对硝基苯酚

采用液相共还原法在没有表面活性剂条件下原位制备Ag/rGO纳米催化材料,并用XRD、EDX、FTIR、Raman、SEM和TEM对所得产物进行了详细表征。结果表明:氧化石墨烯和银离子同时被还原,直径约为5nm的银纳米粒子均匀负载在石墨烯片层上。所制备的Ag/rGO纳米催化剂对硼氢化钠还原对硝基苯酚(4-NP)具有明显的催化活性;当Ag负载量(质量分数)为10%时,该反应在室温下的反应速率常数可达到0.332min-1,表观活化能为34.4kJ·mol-1。该Ag/rGO纳米复合粒子有望成为还原对硝基苯酚的工业催化剂。     

镍负载TiO_2/聚乙烯亚胺/石墨烯纳米复合催化剂的制备及性能

首先采用改进的Hummers法制备了氧化石墨烯(GO),再以聚乙烯亚胺(PEI)修饰的氧化石墨烯为载体,并以硫酸钛和氯化镍为前驱体,利用水热法在180℃下以PEI为交联剂制得镍负载的TiO_2/PEI/石墨烯纳米复合催化剂(Ni-TiO_2/PEI/RGO)。通过紫外-可见分光光度计(UV-vis)、傅里叶变换红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)、X射线衍射(XRD)等测试手段对催化剂进行了表征。结果表明,Ni-TiO_2/PEI/RGO纳米复合催化剂中镍负载TiO_2纳米粒子与石墨烯能够均匀复合,并具有较小的晶粒尺寸,孔径分布主要在4~30 nm,比表面积为241.77 m2/g,镍的负载量为2.35%(质量分数),二氧化钛的负载量为17.46%(质量分数)。考察了该催化剂在Na BH4存在下对对硝基苯酚(4-NP)还原生成对氨基苯酚(4-AP)的催化活性。结果表明,使用Ni-TiO_2/PEI/RGO催化剂4-NP降解率为98%,且催化剂重复使用9次后,4-NP降解率仍能保持90%以上。     

基于蛋壳膜基碳点合成Ag/E-CDs/Fe3O4及其催化还原性能

采用FeCl3?6H2O、尿素、硝酸银为原料,以碳量子点为还原剂,通过水热和光催化两步法合成了Ag/E-CDs/Fe3O4复合物(ECIA).利用鸡蛋壳膜制备了碳量子点表面活性基团,先合成了E-CDs/Fe3O4,然后在光照条件下,Ag粒子进一步沉积于E-CDs/Fe3O4表面.采用XRD、FTIR、SEM、TEM和荧光光谱(PL)等对产物进行表征.以水体中的对硝基苯酚(4-NP)为模拟污染物,研究了ECIA的催化还原性能.探讨了复合物中含Ag量、催化剂用量、4-NP初始浓度对催化还原反应的影响.结果表明,E-CDs/Fe3O4与Ag粒子复合后提高了催化剂的催化活性,但复合物含Ag量过高会降低催化剂催化活性,其中,硝酸银添加量为2 mg时所得样品ECIA-2催化活性最佳,对4-NP的催化还原反应符合一级动力学方程,室温下该反应的ki为0.6441 min–1.     

纳米镍铁双金属的制备及其处理硝基苯酚废水研究

应用室温固相反应法制备了Ni Fe双金属纳米材料,利用XRD、SEM等技术对合成材料进行了表征,并考察了所合成纳米材料对废水中对硝基苯酚(4-NP)的催化还原性能。结果显示,合成的Ni50Fe50双金属对4-NP的催化还原效果最好,反应速率常数为0.417 min-1,活化能为7.514 k J/mol。Ni Fe双金属纳米材料可作为潜在的优良催化剂用于4-NP废水的处理。     

氧化石墨烯的可控还原及表征

采用Hummers修正法制备氧化石墨烯(GO),用壳聚糖(CS)作为“绿色”无毒还原剂,以反应温度和反应时间来控制氧化石墨烯的还原程度。用红外光谱、紫外可见吸收光谱、拉曼光谱和X射线衍射等多种表征手段研究不同还原程度的还原氧化石墨烯的结构与性能。结果表明,改变温度不能有效地控制氧化石墨烯的还原程度;在50℃低温环境下,控制反应时间可以得到不同还原程度的还原氧化石墨烯,为进一步研究不同还原程度还原氧化石墨烯的非线性光学性质奠定了基础。     

低温等离子体制备石墨烯及其性能研究

本文以石墨为原料采用改进的Hummers法制备GO,并采用低温等离子体对所制备的氧化石墨烯进行还原得到还原石墨烯。通过扫描电镜(SEM)、透射电镜(TEM)、傅里叶变换红外(FT-IR)、和X-射线衍射(XRD)等手段对氧化石墨烯及还原石墨烯进行了表征,结果表明GO经过N2、Ar等离子体处理后均得到了有效的还原。     

Graphene-Based Polymer Composites and Their Applications

Recently, graphene has attracted both academic and industrial interest because it can produce a dramatic improvement in properties at low filler content. The utilization of graphene-based materials in the fabrication of nanocomposities with different polymer matrixes has been explored. This review article presents and discusses the development of graphene-based polymer composites and their applications in different fields such as electronics devices, energy storage, sensors, ESD and EMI shielding and biomedical applications.     

石墨烯导电粉末涂料的制备与研究

将石墨烯邦定至粉末底粉的表面,在固化过程中,石墨烯可迁移至涂层表层,成膜后制备导电型石墨烯粉末涂料(邦定法)。作为对比,将石墨烯通过挤出机混炼后,完全分散在涂层中,制备导电型石墨烯粉末涂料(内挤法)。结果发现:石墨烯用量同样为0.3%时,内挤法涂层表面电阻为10 ¹² Ω,而邦定法可降低至10 ⁶ Ω。邦定技术可大大降低石墨烯的用量,降低成本。采用红外光谱对粉末涂料的化学结构进行表征,通过差示扫描量热仪(DSC)测定其固化过程,并探讨了石墨烯的添加量对涂层表面电阻的影响。     

石墨烯涂料专利信息分析

通过对石墨烯涂料方面的专利信息的检索,从宏观层面统计分析了石墨烯涂料相关专利申请信息,并从专利申请的发展态势、区域分布、主要申请人、技术主题等几个方面对数据进行了分析,最后,基于分析结果提出了相关建议。     

石墨烯基电磁屏蔽材料研究进展

随着信息技术和电子通信的不断发展,各种电子设备引起的电磁污染受到社会广泛关注,电磁屏蔽材料已成为研究热点.近年来,碳基电磁干扰屏蔽材料得到了很大的发展.特别是石墨烯,一种单原子层厚度的二维材料,具有导电性好、质量轻、化学性能稳定、环境友好、易加工、超高比表面积等独特性能,被认为是新型电磁干扰屏蔽材料的候选材料.对近年来...     

石墨烯基材料的组装和电化学储能应用

石墨烯作为一种新型二维碳材料,因其独特的结构和优异性质受到广泛关注,在众多领域具有广阔的应用空间。然而由于石墨烯片层间存在较强的相互作用,在实际应用过程中极易发生团聚,从而造成片层利用率低以及性能的急剧降低。因此,利用石墨烯的二维基元结构特点,通过组装实现石墨烯片层的有序性搭接以提高其片层的利用率,对石墨烯材料的实际应用具有重要意义。本文归纳了近年来不断出现的石墨烯基材料的组装体及组装方法,重点介绍了不同形态石墨烯组装体的结构特点及其在电化学储能器件中的潜在应用。     

Advances in Biologically Applicable Graphene-Based 2D Nanomaterials

Climate change and increasing contamination of the environment, due to anthropogenic activities, are accompanied with a growing negative impact on human life. Nowadays, humanity is threatened by the increasing incidence of difficult-to-treat cancer and various infectious diseases caused by resistant pathogens, but, on the other hand, ensuring sufficient safe food for balanced human nutrition is threatened by a growing infestation of agriculturally important plants, by various pathogens or by the deteriorating condition of agricultural land. One way to deal with all these undesirable facts is to try to develop technologies and sophisticated materials that could help overcome these negative effects/gloomy prospects. One possibility is to try to use nanotechnology and, within this broad field, to focus also on the study of two-dimensional carbon-based nanomaterials, which have excellent prospects to be used in various economic sectors. In this brief up-to-date overview, attention is paid to recent applications of graphene-based nanomaterials, i.e., graphene, graphene quantum dots, graphene oxide, graphene oxide quantum dots, and reduced graphene oxide. These materials and their various modifications and combinations with other compounds are discussed, regarding their biomedical and agro-ecological applications, i.e., as materials investigated for their antineoplastic and anti-invasive effects, for their effects against various plant pathogens, and as carriers of bioactive agents (drugs, pesticides, fertilizers) as well as materials suitable to be used in theranostics. The negative effects of graphene-based nanomaterials on living organisms, including their mode of action, are analyzed as well.     

石墨烯类复合材料电磁屏蔽研究进展

石墨烯作为新兴碳质材料,因其优异的力学性能、电学性能和热学性能,已成为材料领域研究的热点。而石墨烯本身即具有吸收电磁波的能力,所以其在电磁屏蔽领域也将成为重要的研究对象。本文主要介绍了石墨烯的来源、改性方法,以及电磁屏蔽的原理和计算方法,同时综述了近几年石墨烯类复合材料电磁屏蔽的研究进展。     

Advances in the Analysis of Pharmaceuticals by Using Graphene-Based Sensors

Safe and effective use of drugs relies on proper pharmaceutical analysis. Graphene has been extensively used to construct sensors for this purpose. Over the years, a large variety of pharmaceutical sensors have been developed from graphene or its derivatives. This article reviews the current status of sensor development from graphene and its derivatives, and discusses the use of graphene-based sensors in pharmaceutical analysis. It is hoped that this article offers not only a snapshot of recent advances in the fabrication and use of graphene-based sensors, but also provides insights into future engineering and optimization of the sensors for effective pharmaceutical analysis.     

An Update on Graphene-Based Nanomaterials for Neural Growth and Central Nervous System Regeneration

Thanks to their reduced size, great surface area, and capacity to interact with cells and tissues, nanomaterials present some attractive biological and chemical characteristics with potential uses in the field of biomedical applications. In this context, graphene and its chemical derivatives have been extensively used in many biomedical research areas from drug delivery to bioelectronics and tissue engineering. Graphene-based nanomaterials show excellent optical, mechanical, and biological properties. They can be used as a substrate in the field of tissue engineering due to their conductivity, allowing to study, and educate neural connections, and guide neural growth and differentiation; thus, graphene-based nanomaterials represent an emerging aspect in regenerative medicine. Moreover, there is now an urgent need to develop multifunctional and functionalized nanomaterials able to arrive at neuronal cells through the blood-brain barrier, to manage a specific drug delivery system. In this review, we will focus on the recent applications of graphene-based nanomaterials in vitro and in vivo, also combining graphene with other smart materials to achieve the best benefits in the fields of nervous tissue engineering and neural regenerative medicine. We will then highlight the potential use of these graphene-based materials to construct graphene 3D scaffolds able to stimulate neural growth and regeneration in vivo for clinical applications.     

Using Graphene-Based Materials for Stiff and Strong Poly(ethylene glycol) Hydrogels

Blood-contacting devices are increasingly important for the management of cardiovascular diseases. Poly(ethylene glycol) (PEG) hydrogels represent one of the most explored hydrogels to date. However, they are mechanically weak, which prevents their use in load-bearing biomedical applications (e.g., vascular grafts, cardiac valves). Graphene and its derivatives, which have outstanding mechanical properties, a very high specific surface area, and good compatibility with many polymer matrices, are promising candidates to solve this challenge. In this work, we propose the use of graphene-based materials as nanofillers for mechanical reinforcement of PEG hydrogels, and we obtain composites that are stiffer and stronger than, and as anti-adhesive as, neat PEG hydrogels. Results show that single-layer and few-layer graphene oxide can strengthen PEG hydrogels, increasing their stiffness up to 6-fold and their strength 14-fold upon incorporation of 4% w/v (40 mg/mL) graphene oxide. The composites are cytocompatible and remain anti-adhesive towards endothelial cells, human platelets and Staphylococcus aureus, similar to neat hydrogels. To the best of our knowledge, this is the first work to report such an increase of the tensile properties of PEG hydrogels using graphene-based materials as fillers. This work paves the way for the exploitation of PEG hydrogels as a backbone material for load-bearing applications.