scholarly journals Properties Analysis and Preparation of Biochar–Graphene Composites Under a One-Step Dip Coating Method in Water Treatment

2020 ◽  
Vol 10 (11) ◽  
pp. 3689
Author(s):  
Ze Yu ◽  
Wenxuan Wang ◽  
He Gao ◽  
Daxin Liang
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pyrolysis Temperature ◽  
Dip Coating ◽  
Adsorption Effect ◽  
Graphene Composite ◽  
Coating Method ◽  
One Step ◽  
Dip Coating Method

In order to improve the adsorption efficiency of biochar in water treatment, biochar–graphene (BG) composites were prepared by the one-step dip coating method and applied to remove phthalates from water. Firstly, the materials and equipment needed for the experiment are introduced. The steps of preparing graphene oxide (GO) by the improved Hummers method and BG composites by one-step dip coating are discussed. Then, the morphology characterization, adsorption performance measurement, and isothermal model of BG composites are introduced. Finally, the structure characterization, adsorption kinetics, and adsorption isotherms of BG composites are analyzed. The results show that the properties of biochar could be changed by one-step dip coating, and the biochar could form composites with graphene. Compared with biochar, biochar–graphene composites have greater surface area and porosity. When the pyrolysis temperature was 600 °C, the specific surface area of biochar was 8.4 m2g−1, and the specific surface area of the biochar–graphene composite was 221.3 m2g−1. When the temperature was 300 °C, the specific surface area of biochar was 11.01 m2g−1, and the specific surface area of biochar–graphene composite was 251.82 m2g−1. The formation of graphene on the surface of biochar can increase the stability of the composite and acts as a very high potential active site. The porous structure and surface properties of biochar–graphene composites regulate the adsorption rate of pollutant molecules, thereby improving the adsorption performance. When the adsorption equilibrium was reached, the adsorption effect of phthalate esters on the biochar/graphene composite at the pyrolysis temperature of 600 °C was the best, and the adsorption capacity of Dimethyl phthalate (DMP)was 35.2 mg/g, that of Diethyl phthalate (DEP) was 26.4 mg/g, and that of Dibutyl phthalate (DBP) was 25.1 mg/g. The adsorption effect of DMP was the best. The results of the isotherm study indicate that the adsorption of phthalates by BG composites has great potential, which provides a good theoretical basis for the application of BG composites in environmental protection in China.

scholarly journals Ionothermally synthesized hierarchical porous Schiff-base-type polymeric networks with ultrahigh specific surface area for supercapacitors

RSC Advances ◽  
2017 ◽  
Vol 7 (32) ◽  
pp. 19934-19939 ◽  
Author(s):  
Yuhang Zhao ◽  
Ping Liu ◽  
Xiaodong Zhuang ◽  
Dongqing Wu ◽  
Fan Zhang ◽  
...  
Keyword(s):  
Schiff Base ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Synthesis Method ◽  
Ionothermal Synthesis ◽  
Polymeric Network ◽  
Polymeric Networks ◽  
Hierarchical Porous ◽  
One Step

A hierarchical porous polymeric network (HPPN) with ultrahigh specific surface area up to 2870 m2 g−1 was synthesized via a one-step ionothermal synthesis method without using templates.

scholarly journals The preparation of synthetic graphite materials with hierarchical pores from lignite by one-step impregnation and their characterization as dye absorbents

RSC Advances ◽  
2019 ◽  
Vol 9 (22) ◽  
pp. 12737-12746 ◽  
Author(s):  
Tian Qiu ◽  
Jian-Guo Yang ◽  
Xue-Jie Bai ◽  
Yu-Ling Wang
Keyword(s):  
Carbon Source ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Large Specific Surface Area ◽  
Hierarchical Pores ◽  
One Step ◽  
Synthetic Graphite

Herein, synthetic graphite materials with hierarchical pores and large specific surface area were prepared by one-step impregnation with lignite as the carbon source, H2SO4 as the oxidant, and H3PO4 as the activator.

scholarly journals Photocatalytic Performance of Carbon Monolith/TiO2Composite

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Marina Maletić ◽  
Marija Vukčević ◽  
Ana Kalijadis ◽  
Zoran Laušević ◽  
Mila Laušević
Keyword(s):  
Photocatalytic Activity ◽  
Thermal Treatment ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Dip Coating ◽  
Surface Oxygen ◽  
Surface Oxygen Groups ◽  
Carbon Monolith ◽  
Oxygen Groups

The new and simple approach for deposition of catalytically active TiO2coating on carbon monolith (CM) carrier was presented. CM photocatalysts were impregnated with TiO2using titanium solution and thermal treatment, and their photocatalytic activity was investigated in the process of methylene blue (MB) photodegradation. For the purpose of comparison, CM composite photocatalysts were prepared by dip-coating method, which implies binder usage. The presence of TiO2on CM carrier was confirmed by Raman spectroscopy and scanning electron microscopy. The sorption characteristics of CM and the role of adsorption in the overall process of MB removal were evaluated through amount of surface oxygen groups obtained by temperature-programmed desorption and specific surface area determined by BET method. CM has shown good adsorption properties toward MB due to high amount of surface oxygen groups and relatively high specific surface area. It was concluded that photocatalytic activity increases with CM disc thickness due to increase of MB adsorption and amount of deposited TiO2. Good photocatalytic activity achieved for samples obtained by thermal treatment is the result of better accessibility of MB solution to the TiO2particles induced by binder absence.

scholarly journals Effects of the Pyrolysis Temperature on Adsorption of Carbamazepine and Ibuprofen by NaOH Pre-treated Pine Sawdust Biochars

2020 ◽  
Vol 42 (2) ◽  
pp. 29-39
Author(s):  
Jinwoo Kwak ◽  
Sangwoo Park ◽  
Jaegwan Shin ◽  
Kangmin Chon
Keyword(s):  
Ionic Strength ◽  
Specific Surface ◽  
Pore Size ◽  
Surface Area ◽  
Specific Surface Area ◽  
Pore Volume ◽  
Pyrolysis Temperature ◽  
Repulsive Interaction ◽  
Pine Sawdust ◽  
Adsorption Mechanisms

Objective: The main purpose of this study was to examine the impacts of the pyrolysis temperature on the removal of pharmaceuticals (i.e., ibuprofen (IBF) and carbamazepine (CBZ)) using NaOH pre-treated biochars produced from pine sawdusts.Methods:Two different types of kinetic and isotherm models were applied to investigate the adsorption mechanisms of IBF and CBZ by the NaOH pre-treated biochars produced at 600℃ (PB-600) and 800℃ (PB-800). In addition, the removal efficiencies of IBF and CBZ by PB-600 and PB-800 were compared under various conditions (adsorbent doses: 5-40 mg/L; 20-160 mg/L; temperature: 15-45℃; ionic strength: 0-0.5 M) to assess their feasibility as an alternative adsorbent for the removal of pharmaceuticals. Results and Discussion:PB-800 could more effectively remove CBZ and IBF than PB-600 because of its larger specific surface area (PB-600 = 408.70 m<sup>2</sup>/g; PB-800 = 472.92 m<sup>2</sup>/g), pore volume (PB-600 = 0.336 cm<sup>3</sup>/g; PB-800 = 0.658 cm<sup>3</sup>/g), and pore size (PB-600 = 4.63 nm; PB-800 = 6.25 nm). The Langmuir isotherm was more suitable for adsorption of IBF by PB-600 and the Freundlich isotherm was well fitted to the adsorption of CBZ by PB-600 and adsorption of CBZ and IBF by PB-800. The adsorption of CBZ by PB-600 and PB-800 was not affected by temperature while the removal efficiency of IBF was decreased with increasing the temperature due to the increased repulsive interaction between IBF and the biochars. Furthermore, the effects of the ionic strength on the adsorption of IBF were more pronounced than that of CBZ due to the differences in the surface charge properties.Conclusions:The higher pyrolysis temperature can improve the physicochemical properties of the NaOH pre-treated pine sawdust biochars associated with the removal of the pharmaceuticals (i.e., CBZ and IBF). Moreover, the adsorption mechanisms of CBZ and IBF by the biochars were strongly influenced by their specific surface area, pore volume and pore size.

scholarly journals Towards the Continuous Hydrothermal Synthesis of ZnO@Mg2Al-CO3 Core-Shell Composite Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2052
Author(s):  
Ian Clark ◽  
Jacob Smith ◽  
Rachel L. Gomes ◽  
Edward Lester
Keyword(s):  
Composite Material ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Single Phase ◽  
Core Shell ◽  
Composite Nanomaterials ◽  
One Step ◽  
Double Hydroxide ◽  
Shell Composite

Core-shell Zinc Oxide/Layered Double Hydroxide (ZnO@LDH) composite nanomaterials have been produced by a one-step continuous hydrothermal synthesis process, in an attempt to further enhance the application potential of layered double hydroxide (LDH) nanomaterials. The synthesis involves two hydrothermal reactors in series with the first producing a ZnO core and the second producing the Mg2Al-CO3 shell. Crystal domain length of single phase ZnO and composite ZnO was 25 nm and 42 nm, respectively. The ZnO@LDH composite had a specific surface area of 76 m2 g−1, which was larger than ZnO or Mg2Al-CO3 when produced separately (53 m2 g−1 and 58 m2 g−1, respectively). The increased specific surface area is attributed to the structural arrangement of the Mg2Al-CO3 in the composite. Platelets are envisaged to nucleate on the core and grow outwards, thus reducing the face–face stacking that occurs in conventional Mg2Al-CO3 synthesis. The Mg/Al ratio in the single phase LDH was close to the theoretical ratio of 2, but the Mg/Al ratio in the composite was 1.27 due to the formation of Zn2Al-CO3 LDH from residual Zn2+ ions. NaOH concentration was also found to influence Mg/Al ratio, with lower NaOH resulting in a lower Mg/Al ratio. NaOH concentration also affected morphology and specific surface area, with reduced NaOH content in the second reaction stage causing a dramatic increase in specific surface area (> 250 m2 g−1). The formation of a core-shell composite material was achieved through continuous synthesis; however, the final product was not entirely ZnO@Mg2Al-CO3. The product contained a mixture of ZnO, Mg2Al-CO3, Zn2Al-CO3, and the composite material. Whilst further optimisation is required in order to remove other crystalline impurities from the synthesis, this research acts as a stepping stone towards the formation of composite materials via a one-step continuous synthesis.

Research on Hydrogen Sulfide Adsorption by Oil Shale and its Spent Char

2012 ◽  
Vol 610-613 ◽  
pp. 1439-1442
Author(s):  
Hong Qin ◽  
Chuang Yao ◽  
Hong Peng Liu ◽  
Qing Wang ◽  
Chun Xia Jia
Keyword(s):  
Hydrogen Sulfide ◽  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
Oil Shale ◽  
Nitrogen Adsorption ◽  
Adsorption Effect ◽  
Nitrogen Adsorption Isotherms ◽  
Adsorption Curve ◽  
Made In

Huadian oil shale and its spent char were selected to explore the adsorption properties of oil shale and oil shale char. A bench-scale adsorption system was established for capturing hydrogen sulfide in this test. What’s more, the nitrogen adsorption isotherms test was made in automatic and rapid specific surface-area-analyzer of American’s Gemini2380, which found the adsorption curve and desorption loop of the modified oil shale and oil shale char. Meanwhile, the experiment calculated and analyzed the specific surface area and pore size distribution of samples with BJH theory. The result shows that the adsorption capacity of oil shale char is greater than oil shale. The rougher the pore structure of the adsorbent samples the greater the pore volume, the larger the specific surface area, the better the adsorption effect of H2S.

A sponge-templated sandwich-like cobalt-embedded nitrogen-doped carbon polyhedron/graphene composite as a highly efficient catalyst for Zn–air batteries

Nanoscale ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 973-982 ◽  
Author(s):  
Jia-Jun Cai ◽  
Qing-Yan Zhou ◽  
Bing Liu ◽  
Xiao-Fei Gong ◽  
Yun-Long Zhang ◽  
...  
Keyword(s):  
Porous Structure ◽  
Dip Coating ◽  
Hierarchical Porous Structure ◽  
Efficient Catalyst ◽  
Nitrogen Doped ◽  
Graphene Composite ◽  
Hierarchical Porous ◽  
Coating Method ◽  
Dip Coating Method ◽  
Nitrogen Doped Carbon

Sandwich-like Co-embedded N-doped carbon polyhedron/graphene with a hierarchical porous structure was fabricated through a solution dip-coating method using sponge templates.

One-Step Process of NH3 detection Based on Nanofibrous Membranes/QCM System

2014 ◽  
Vol 530-531 ◽  
pp. 41-44
Author(s):  
Li Zhu Chen ◽  
Yong Tang Jia ◽  
Cheng Cheng Yan ◽  
Hui Yu ◽  
Feng Chun Dong
Keyword(s):  
Specific Surface ◽  
Surface Area ◽  
Specific Surface Area ◽  
High Specific Surface Area ◽  
Electrospinning Technique ◽  
Carboxyl Content ◽  
Step Process ◽  
Ammonia Sensing ◽  
Combination System ◽  
One Step

One-step process of poly(styrene-co-maleic acid)(PS-PMA) nanofibers/QCM combination system was proposed as a novel ammonia detection in this study. Nano-sized PS-PMA fibers were deposited on the QCM electrodes via electrospinning technique directly, which can retain the original high specific surface area of PS-PMA nanofibers, and simplify NH3detection process significantly. Experimental results showed that this new PS-PMA nanofibers/QCM sensor exhibited excellent ammonia sensing performances, such as rapid response and good reproducibility. Moreover, the carboxyl content on the surface of PS-PMA membranes was also determined as well as the specific surface area in order to study the structure-properties relationships.

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