Gold nanoparticle-decorated reduced graphene oxide as a highly effective catalyst for the selective α,β-dehydrogenation of N-alkyl-4-piperidones

In this work, cobalt Fischer–Tropsch synthesis (FTS) catalyst supported on various carbon materials, i.e., carbon nanotube (CNT), activated carbon (AC), graphene oxide (GO), reduced graphene oxide (rGO), and carbon nanofiber (CNF), were prepared via impregnation method. Based on TGA, nitrogen physisorption, XRD, Raman spectroscopy, H2-TPR, NH3-TPD, ICP, SEM, and TEM characterization, it is confirmed that Co3O4 particles are dispersed uniformly on the supports of carbon nanotube, activated carbon and carbon nanofiber. Furthermore, the FT catalyst performance for as-prepared catalysts was evaluated in a fixed-bed reactor under the condition of H2:CO = 2:1, 5 SL·h−1·g−1, 2.5 MPa, and 210 °C. Interestingly, the defined three types of carbon materials exhibit superior performance and dispersion compared with graphene oxide and reduced graphene oxide. The thermal stability and pore structure of the five carbon materials vary markedly, and H2-TPR result shows that the metal–support interaction is in the order of Co/GO > Co/CNT > Co/AC > Co/CNF > Co/rGO. In brief, the carbon nanofiber-supported cobalt catalyst showed the best dispersion, the highest CO conversion, and the lowest gas product but the highest heavy hydrocarbons (C5+) selectivity, which can be attributed to the intrinsic property of CNF material that can affect the catalytic performance in a complicated way. This work will open up a new gateway for cobalt support catalysts on various carbon-based materials for Fischer–Tropsch Synthesis.

Polymer electrolyte membrane fuel cells (PEMFC) are one of the most efficient energy conversion systems for portable, stationary and automotive applications. In spite of the tremendous progress in PEMFC in terms of research and applications, there are still significant barriers to their commercialization mainly due to high cost of Pt catalyst and durability issues. Additionally, the sluggish oxygen reduction reaction (ORR) is another problem of PEMFC. Platinum (Pt) nanoparticles extensively used as catalyst in PEMFC have not only high cost and performance problems but also have low abundance. The electrocatalytic activities of the Pt based catalysts depend on several parameters such as catalyst support, catalyst preparation technique, accessibility of the metal on the support, and testing conditions. Catalyst support materials are of great importance in regulating the properties of catalyst nanoparticles such as shape, size, and dispersion. Carbon black, the most commonly used commercial catalyst support, has several limitations which cause the degradation of catalyst activity and performance. Graphene is an increasingly important material with distinct properties such as high electrical conductivity, high contact surface area and enormous stability. Here we aim to use of graphene and its hybrids as the catalyst support in PEMFC due to their high surface area, high conductivity and chemical stability [1]. In this regard, graphene nanoplatelets, reduced graphene oxide, functionalized graphenes and graphene based hybrids. Graphene based hybrid supports were prepared by mechanical mixing of graphene at varying ratios of other carbon materials including carbon black (CB), CNT, carbon nanopowder (CNP) and carbon nanofibers. Graphene supported Pt nanoparticles were prepared by means of impregnation-reduction, supercritical carbon dioxide deposition, electrospinning/electrospraying, electrophoresis and photodeposition. Highly dispersed and uniformly decorated Pt nanoparticles with a small particle size (1-2 nm) were obtained. Moreover, remarkably enhanced electrocatalytic activity for oxygen reduction reactions and fuel cell performances for graphene based hybrids were achieved [1-3]. Best results in terms of electrocatalytic activity towards oxygen reduction reaction, fuel cell performance and power output were obtained with Pt/GO-CNT, Pt/GO-CB and Pt/GO-CNP hybrid catalysts. It seems that carbon materials added to graphene effectively modify the array of graphene and provide synergistic effect. Acknowledgements The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 696656 (Graphene Flagship) References Quesnel et al., 2D Mater., 2017, 2, 030204.Daş, S. Alkan Gürsel, L. Işikel Şanli, A. Bayrakçeken Yurtcan, Int. J. Hydrogen Energy, 2017, 42, 19246.Işıkel Şanlı, V. Bayram, S. Ghobadi, N. Düzen, S. Alkan Gürsel, Int. J. Hydrogen Energy, 2017, 42,1085.

Supercapacitors prevail over batteries in certain niche markets, owing mainly to its much higher power density and the fit-and-forget benefits once installed. However, for certain applications, the power performance of supercapacitors may still not be sufficient. Herein, reduced graphene oxide is incorporated with activated carbon for supercapacitor electrodes to further improve their power densities. Our preliminary results validated this idea and achieved around 50% power density increase. Graphene materials have been widely studied recently for supercapacitor applications, especially after the paper published by Ruoff et al in 2008 [1]. Various forms of graphene materials, graphene/metal compounds, graphene/polymer composites, and graphene/activated carbon hybrids have all been examined for supercapacitors, and some of them exhibited attracting performances. However, the industry is still quite reluctant to adopt graphene materials in their commercial products, and factors such as lower packing density, in-sufficient performance improvement, and higher cost, in comparison to the high-surface-area activated carbon (AC) currently in use, could be the major obstacles. Efforts have been devoted to increase the packing density of graphene materials by compression [2] or liquid-mediated approach [3]. Also, microwaved graphene oxide [2] and graphene oxide/biomass mixtures using conventional carbon activation technologies [4] have been proposed and certain performance improvements were reported. However, either using graphene materials directly as the major working medium or as carbon source for porous carbon via conventional activation technology is not desirable compared to currently used AC if only moderate performance improvement was achieved.Our approach here is to use graphene materials as additives, rather than acting as the major active material, so as to improve the capacitive charge storage ability and decrease the resistance of the cell. Compared to currently used carbon black as the additive, graphene materials are superior with much better electrochemical performance and comparable electrical conductivity. Moreover, graphene materials can be readily incorporated into the industrial electrode fabrication process without sacrificing of the packing density of the resulting electrodes. Therefore, a simple experiment was designed and conducted in this report. Briefly, the graphene oxide was first synthesized by Hummer’s method. And 200 mL of 1 mg/mL graphene oxide aqueous solution was reduced by 2 mL hydrazine hydrate at 100 °C under vigorous stirring for 24 hours. A control sample was fabricated by mixing Norit SX4 activated carbon (AC), super P carbon black (CB) and PTFE (85%:8%:7%). The active material for Samples 1 and 2 was a mixture of AC and reduced graphene oxide (RGO) at the same weight ratio of ca. 11:1. However for Sample 1, AC was blended with the graphene oxide in the solution prior to its reduction, whereas for Sample 2, both AC and RGO powder were grinded into a mortar (ACRGO). Afterwards, the same weight ratios as the Control Sample was used to fabricate electrodes, i.e., ACRGO:CB:PTFE (85%:8%:7%). Three symmetric C/C supercapacitors using different electrodes were then constructed and tested. As shown in Fig. 1, the rectangular shapes of the CV curves are observed for all samples. The specific capacitance of the Control Sample is 103 F/g, and 133 F/g for Sample 1; 124 F/g for Sample 2, indicating an increase of specific capacitance by 29% and 20%, respectively, attributable to the additional capacitive charge storage from the reduced graphene oxides. Based on EIS tests shown in Fig. 2, the equivalent series resistances (ESRs) of the cells at 1k Hz are determined to be 0.9 Ω for Control Sample, 0.8 and 0.7 Ω for Samples 1 and 2, respectively. Using the combined mass of the two electrodes, the maximum power densities of Samples 1 and 2 are calculated as 45% and 55% larger than that of the Control Sample. In summary, by adding small amount (=7.1w%) of RGO, supercapacitors with moderately increased capacitance, reduced ESR and significantly improved power density can be produced.[1] M. Stoller, S. Park, Y. Zhu, J. An, R. Ruoff, Nano Letters, 8 (2008) 3498-3502.[2] S. Murali, N. Quarles, L.L. Zhang, J.R. Potts, Z. Tan, Y. Lu, Y. Zhu, R.S. Ruoff, Nano Energy, 2 (2013) 764-768.[3] X. Yang, C. Cheng, Y. Wang, L. Qiu, D. Li, Science, 341 (2013) 534-537.[4] Y. Chen, X. Zhang, H. Zhang, X. Sun, D. Zhang, Y. Ma, RSC Advances, 2 (2012) 7747-7753. Figure 1. Cyclic voltammograms at 10 mV/s. Figure 2. Nyquist plots of the cells, with the insertion showing the high frequency regions.

With the increasing contamination and depletion problems of fossil fuel, an alternative technology, the proton exchange membrane fuel cells (PEMFCs), has been considered as the most promising power source of the future in the field of the portable electrics and vehicles. The hydrogen fuel cell is expected to be the excellent choice because of its zero-carbon emission and high power density among variable fuel cells. Platinum (Pt) nanoparticles are the most widely used catalyst in the hydrogen fuel cell as it has high activity and selectivity for the hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR). However, the utilization of precious platinum catalyst also has many shortcomings such as Pt agglomeration, which decrease the life time of the PEMFC, and the high cost of this material. Decreasing the loading of Pt on electrodes, cathode and anode, is one of the most important challenges for this field. Catalyst support materials with high surface area, high electrical conductivity and good catalyst interaction may decrease the amount of catalyst needed and improve the catalytic efficiency. With this aim, many carbon materials such as carbon black, Vulcan XC-72, mesoporous carbon and carbon nanotubes have been investigated as a catalyst support in the hydrogen fuel cell [1, 2]. Graphene, a two-dimensional (2D) structure of honeycomb lattice material, exhibits excellent electrical conductivity (104.36 S·cm-1), large specific surface area (~2630 m2·g-1), good thermal and mechanical stability, has recently attracted great attention as a catalyst support [3]. Several publications have successfully developed Pt catalyst supported on reduced graphene oxide (rGO) to improve the PEMFCs performance. This process of synthesizing Pt-graphene based catalyst mostly starts from graphene oxide (GO) produced by Hummers method, which leads to environmental and safety issues (use KMnO4, strong oxidizing agents and concentrated H2SO4), takes a long time and costly [4]. This work presents an alternative to Hummer’s method to produce GO and rGO by the Electrochemical Exfoliation of Graphite. A simple two electrodes configuration, counter electrode in different electrolyte solutions (NH4NO3 or (NH4)2SO4) has been carried out to produce high quality exfoliated graphene oxide (EGO) in a fast, efficient and environmental friendly way, producing also high yield in comparison with the traditional Hummer’s method. Additionally, the functional groups of nitrogen and sulphur coming from the electrolyte solution are able to be introduced into EGO, which influence the local electronic structure as well as improve polarization of the graphene network [5, 6]. Therefore, this study presents an environmentally friendly and a cost-effective approach to prepare. Pt nanoparticles supported on EGO, which were synthesized by a modified polyol reduction method to compare with the traditional Pt supported on carbon black (Pt-CB) and rGO produced by Hummers’ method (Pt-GO) to improve the efficiency and the long time performance of a PEMFCs. Successful preliminary results can be observed in Fig 1, which shows that Pt-EGO can improve the electrochemical surface area (ECSA) over Pt-CB and Pt-GO. Meanwhile, Pt-EGO can influence the durability of the catalyst with chrono amperometry measurement. This study will discuss the characterisation of developed catalysts and their efficacy in a working fuel cell system.

Uniform, Scalable, High-Temperature Microwave Shock for Nanoparticle Synthesis through Defect Engineering

DOI: 10.1002/aenm.201301565 The increasing demand for environmentally friendly industries and effective pollution control has attracted great attention from both academic and industrial organizations for the development of new processes and novel materials. As a major air pollutant, hydrogen sulfi de (H 2 S), originating from various sources (natural gas processing, the refi ning and consumption of fossil fuel, etc.) must urgently be removed and reused due to its high toxicity towards the environment (acid rain) and living organisms. [ 1 ] Great efforts have been made to explore the effective removal of H 2 S and in most cases transitionmetal oxides and mixed oxides are used as adsorbents and/or catalysts for the oxidation of H 2 S, whereas others use zeolite, activated carbon (AC), and carbon nanotubes (CNTs) as adsorbents. [ 2,3 ] Carbon materials have appealing properties as adsorbents or catalyst supports for the removal of H 2 S. For instance, AC or CNTs have been widely used as supports of catalysts (ZnO, NiS 2 , etc.) for the catalytic oxidation of H 2 S. [ 3 ] Nevertheless, the regeneration and full utilization of the H 2 S and the development of high-performance adsorbents are still hard to realize. Thus, it is necessary to develop an appropriate approach to eliminate and recycle H 2 S to realize its regeneration and environmental protection. As a fascinating carbon material, graphene possesses excellent electrical, thermal, and mechanical properties due to its unique 2D structure, making it versatile in fundamental science and various applications, such as energy storage, sensors, adsorption, etc. [ 4 ] Due to its large and fully accessible surface and excellent conductivity, the use of graphene in the removal of H 2 S has been examined both experimentally and theoretically. [ 1a, 2, 5 ] Density functional theory (DFT) studies show that H 2 S molecules are physisorbed only on the surface of graphene, thus, in most cases, graphene has a low catalytic activity for H 2 S oxidation and also a low adsorption capacity. Graphene oxide (GO), the most important derivative of graphene, is decorated by abundant oxygen-containing groups on the graphene layer, and these help improve the reactivity and processability due to their hydrophilic nature. Although GO suffers from poor conductivity due to the destruction of the continuous sp 2

A new green method for the synthesis of reduced graphene oxide–gold nanoparticle (rGO–AuNP) hybrids in aqueous solution that exploits the ability of ascorbic acid (AA) to operate as an effective dual agent for both graphene oxide (GO) and gold ion reduction is reported. Through careful investigation of the production of rGO–AuNP hybrids stabilized with polyvinylpyrrolidone (PVP), several versatile routes were devised with the aim of controlling the size, shape and distribution of AuNPs anchored onto the graphene sheets as well as the GO reduction. Particularly, when rGO is used as a platform for Au ion nucleation, a relative sparse distribution of AuNPs of size ranging from 20 nm to 50 nm is noticed. In contrast, when gold ions are added to the solution prior to any GO reduction, the density of large AuNPs is rather low relative to the uniformly packed small sized AuNPs (3–12 nm). The progress of GO reduction is explained by considering the contribution of the catalytic activity of AuNPs, besides the reducing activity of AA. Finally, a plausible mechanism for the nucleation and distribution of AuNPs onto the graphenic surface is assumed, highlighting the significance of oxygen moieties. The green method developed here is promising for the fabrication of gold–graphene nanocomposites with tunable surface “decoration”, suitable for surface-enhanced Raman spectroscopy (SERS).

Rheological and microstructural characterization of aqueous suspensions of carbon black and reduced graphene oxide

Graphene, a two-dimensional (2D) structure of honeycomb lattice material with long-range π-conjugation, is an ideal catalyst support material due to its large surface area, excellent electrical conductivity, good mechanical and electrochemical stability [1]. It has already been reported that platinum nanoparticles (PtNPs) supported on reduced graphene oxide (rGO), is limited by van der Waals force resulting in the restacked rGO flakes during the reduction process, thereby hindering the transport of fuel gas to approach Pt active sites [2, 3].To overcome this issue, several publications have successfully developed PtNPs catalyst supported on rGO and carbon black (CB) hybrid supporting materials [4]. The synergistic effect between rGO and CB could enhance its activity for oxygen reduction reaction through controlling PtNPs size as well as improve its durability by preventing the agglomeration and corrosion of supporting materials [3]. However, Hummers GO leads to environmental and safety issues (use KMnO4, strong oxidizing agents and concentrated H2SO4) as well as a long-time preparation with high cost [2].Our previous research has already developed a novel graphene-based material prepared by electrochemical exfoliation of graphite, which is faster, more environmentally friendly and has a high yield, intercalated by CB as a bi-support and achieved 50% improvement performance compared with Pt/CB.To further improve catalyst activity, some research proposed that the introduction of nitrogen, especially graphitic N and pyridinic N, on the surface of carbon materials could improve ORR activity and electronic conductivity by changing the local electronic structure as well as polarization of the graphene network with smaller energy band gap [3, 5]. However, the effect and comparation of nitrogen doped rEGO intercalated by CB (NrEGO-CB) and nitrogen doped both EGO and CB (NrEGO-NCB) as bi-support materials to improve the performance of the hydrogen fuel cell have not been studied.In this work, EGO and EGO-CB was doped with nitrogen by hydrothermal treatment with urea as a nitrogen precursor in a Teflon-steel autoclave. Pt catalysts were synthesized by a modified polyol reduction method. Successful preliminary results can be observed in Fig 1, which shows that PtNPs supported on NrEGO-CB with ratio of 2 to 3 has a maximum power density of 1.2 W cm-2. It is more than 4 times compared with that 0.3 W cm-2 of Pt/CB.

Palladium nanocatalysts supported on reduced graphene oxide (rGO), multi walled carbon nanotubes (MWCNT), and rGO/CNT composite were synthesized by a wet impregnation method using PdCl2 as a precursor. Palladium loading was 0.3 wt %, and the catalysts were reduced at 300 °C. The catalysts were characterized by inductively coupled plasma, Brunauer−Emmett−Teller (BET) analysis, Fourier transform infrared spectroscopy, X-ray powder diffraction, transmission electron microscopy, temperatue-programmed reduction, temperatue-programmed desorption, and Raman spectroscopy. The performance of the catalysts was investigated for hydro-purification of crude terephthalic acid (CTA) containing 2100 ppm 4-carboxybenzaldehyde (4-CBA) as an impurity. The reaction products were analyzed by HPLC to determine the amounts of 4-CBA, benzoic acid, and p-toluic acid. Pd/rGO–CNT catalyst had excellent performance in terms of both selectivity and 4-CBA conversion. All catalysts exhibited more than 99% removal of 4-CBA. The most desired selectivity, however, was obtained for the catalyst with rGO–CNT as a support. Comparison with the performance of the commercial catalyst (0.5 wt % palladium on activated carbon) indicated that the Pd/rGO–CNT catalyst had a better performance.

Low-temperature direct conversion of methane to methanol over carbon materials supported Pd-Au nanoparticles

Supercapacitors (SCs) are energy storage devices with a growing interest thanks to their high-power charge and discharge process and long-cycle life. Their main drawback, when compared to more common devices such as batteries, consists in a low energy density. The performances of SCs can however be improved with the coupling of additives to the main active material, which usually is an Activated Carbon. The most common additive is instead Carbon Black (CB), while more recently also Graphene-derived materials have been successfully exploited for this purpose, as the reduced Graphene Oxide (rGO). However, besides raw materials choice, details related to the manufacturing have a leading importance in the attempt to obtain novel active materials with an industrial-ready process which also looks toward the needs of more environmental friendly and economically convenient solutions. In this work, a physical-chemical analysis is performed to show temperature effects on CB, GO and on a CB/GO water-based slurry with helpful results about GO reduction and CB/GO nanocomposite formation.

Reduced graphene oxide (RGO) based electrochemical double-layer capacitors (EDLC), have been extensively studied as good power capability can be achieved but they suffer from low capacitances (~100-150 F/g), as the reduced graphene sheets partially restack through π- π interactions limiting the resulting adsorption active surface area.[1] To avoid this restacking different paths have been followed in the literature: using graphene aerogels or expanded graphene structures.[2] In this latter case, an intercalate or pillar is used to space out the graphene layers and recover active surface area. Different nature of pillars or intercalates such as carbon nanotubes, carbon blacks, diamine, aromatic, metallic ions or big macrocyles have been described.[2,3] The results, that will be presented, depict the researches devoted to the development and study of graphene based expanded assemblies designed to be tested as electrode materials for supercapacitors. The material development involves the bridging of graphene oxide derived sheets using alkyl diamine as linkers (Fig. 1a).[3] The production of graphene galleries of height matching that of different alkyl chain length pillars was evidenced, notably with XRD (Fig. 1b). The purpose of this design was to enhance the specific capacitance by limiting graphene sheet restacking and optimizing the inter-sheet distance (d-spacing) or pore size with respect to the ion size, as was previously evidenced with other carbon materials.[4] These materials (named RPs) have been tested electrochemically with various tetraalkylammonium tetrafluoroborate salts in acetonitrile. This approach resulted in adsorption active surface area tuning, yielding clear evidence of the electrolytic ions entering the inter-layer galleries. Indeed only ions with diameter smaller than the d-spacing access the inter-layer galleries.[5a] Ex-situ solid-state NMR analysis were performed to further demonstrate the ionic species adsorption at the material surface. Further optimization dealing with pillar amount or nature and material density tuning showed the high interest of this re-aggregation limitation method, as gravimetric and volumetric capacitances 4 times higher than that of RGO (230 F/g and 210 F/cm3 respectively) have been achieved (Fig. 1c).[5b] Figure 1: a) Scheme differentiating reduced graphene oxide RGO and pillared graphene structures; b) XRD diffractograms obtained for pillared graphene prepared diamines with different chain lengths (5, 6 and 8 C atoms); c) Volumetric capacitance and power capability tests obtained on a pillared material compared to RGO.

Chemically-reduced graphene-oxide-supported gold nanoparticles and traces of iridium are considered here together with loadings of platinum as catalytic materials for reduction of oxygen in alkaline and acid media, respectively. Comparison is made to the analogous systems based on conventional Vulcan carbon carriers. Gold nanoparticles are prepared by the chemical reduction method, in which the NaBH4-prereduced Keggin-type phosphomolybdate heteropolyblue acts as the reducing agent for the precursor (HAuCl4). Polyoxmetallate (PMo12O40 3-) capping ligands stabilize gold nanoparticle deposits, facilitate their dispersion and attachment to carbon supports. Indeed, it is apparent from the independent diagnostic voltammetric experiments (in 0.5 mol dm-3 H2SO4) that heteropolymolybdates form readily stable adsorbates on nanostructures of both gold and carbon (reduced graphene oxide and Vulcan). It is reasonable to expect that the polyoxometallate-assisted nucleation of gold has occurred in the proximity of oxygenated defects existing on carbon substrates. Under conditions of electrochemical diagnostic experiments (performed in 0.1 mol dm-3 KOH) the phosphomolybdate adsorbates are removed from the interface as they undergo dissolution in alkaline medium; and the Au nanoparticles (Au loading, 30 µg cm-2) remain well-dispersed on the carbon as evident from transmission electron microscopy. High electrocatalytic activity of the reduced-graphene oxide-supported Au nanoparticles toward reduction of oxygen in alkaline medium is demonstrated using cyclic and rotating ring-disk electrode (RDE) voltammetric experiments. Among important issues are possible activating interactions between gold and the support, as well as presence of structural defects existing on poorly organized graphitic structure of reduced graphene oxide (as evident from Raman spectroscopy). When using the silica or titania functionalized reduced graphene oxide as carriers for Au (or Ir) and Pt nanoparticles, the resulting systems have exhibited typically higher (certainly not lower) O2-reduction currents (relative to those recorded at conventional Vulcan-supported Pt at the same loading) in acid medium (0.5 M H2SO4). The RDE data are consistent with even lower formation of hydrogen peroxide. Furthermore, the durability of this family of catalysts was outstanding. Finally, by doping the reduced graphene oxide supported Pt with traces of Ir (<1 µg cm-2), decreases amounts of produced H2O2 (<1%) at potentials 0.6 V (vs RHE) or lower.

Lithium ion batteries (LIBs) with high power and energy density are desirable for use in portable electronics and electric vehicles. Silicon (Si) and tin (Sn) are among the most promising candidates for LIB anodes owing to their high theoretical specific capacity. However, both Si and Sn suffer from a dramatic volume change during lithiation/delithiation. Extensive efforts have been made using nanostructures to overcome this issue and improve the electrochemical performance of Si and Sn anodes. Carbon black (CB) is usually added to either electrode in LIBs to provide electrical conductivity. Because CB does not contribute to capacity, minimizing its use can lower the mass of battery to further increase the energy density. Due to the high aspect ratio and excellent electrical conductivity, sheet-like material reduced graphene oxide (RGO) is able to form a conducting network at much lower volume fractions than CB based on the percolation theory. In this work, Si and Sn based anodes were prepared respectively using an emulsiontemplating strategy where active material nanoparticles were confined in the oil phase of the formed emulsions. CB stabilized these emulsions and formed a conductive network. We reduced the total carbon loading of Si anode by replacing a small amount of CB with RGO. In Si anode with a lower total carbon content, the formation of a conducting network consisting of CB and RGO contributed to a good cycle performance, which is comparable to the anode with double carbon loading but no RGO. We also studied the influence of the oil on the structure and electrochemical behavior of emulsion-templated Sn based anode. Density and vapor pressure of the oils affected the creaming and drying rates of the emulsions, which in turn affected the structures of dried emulsions and anode performance. Emulsion droplet size also had an impact on the drying process. Sn anode prepared with hexadecane that had a smaller density than water and a low vapor pressure along with smaller oil droplet showed the highest capacity and capacity retention which were attributed to the smooth and dense morphology with no cracking. Aqueous suspensions of CB and mixtures of CB and RGO were also examined. It was found that the concentrations of CB and pH conditions played major roles in determining the rheological properties and microstructures of the suspensions. The combinations of optical microscopy, cryogenic and conventional scanning electron microscopy, transmission electron microscopy were used to characterize the structures of fresh