Graphene/Li-Ion battery

Density function theory calculations were carried out to clarify storage states of Lithium (Li) ions in graphene clusters. The adsorption energy, spin polarization, charge distribution, electronic gap, surface curvature and dipole momentum were calculated for each cluster. Li-ion adsorbed graphene, doped by one Li atom is spin polarized, so there would be different gaps for different spin polarization in electrons. Calculation results demonstrated that a smaller cluster between each two larger clusters is preferable, because it could improve graphene Li-ion batteries; consequently, the most proper graphene anode structure has been proposed.Comment: 19 pages, 7 figures, 1 tabl

The application of regenerable sorbents for mercury capture in gas phase

Mercury is a well-known toxic element, and flue gas streams emitted from coal-fired utilities are one of the largest anthropogenic sources of this element. This study briefly reviews the proposed technologies for reducing mercury emissions from coal combustion, focusing on an emerging process which involves the use of regenerable sorbents and especially those loaded with noble metals. Among the mercury species formed during coal combustion, elemental mercury is the most difficult to remove from the flue gases due to its low reactivity and insolubility in water. The widespread interest in using regenerable sorbents with metals is due to their ability to retain elemental mercury. With this technology, not only can efficiencies of 100 % be reached in the retention of elemental mercury but also a way to avoid the generation of new wastes loaded with mercury. This study considers the main aspects that must be taken into account when developing effective regenerable sorbents for mercury capture, with special attention to sorbents containing noble metals. The characteristics of this process are compared with those of other processes in a more advanced state of development.The financial support for this work was provided by the projects CTQ2014-58110-R and GRUPIN14-031. The authors thank PCTI Asturias for awarding N. Fernández Miranda a pre-doctoral fellowship.Peer reviewe

Advances in tailoring the porosity of tannin-based carbon xerogels

Usually, carbon xerogels are obtained from resorcinol–formaldehyde organic gels. However, more cost-effective and eco-friendly carbon xerogels can be synthesised by using tannins instead of resorcinol, provided that a suitable surfactant is added to prevent the collapse of the structure. The use of tannin, a natural phenolic compound derived from wood, allows obtaining carbon xerogels with controlled porosity, as the porous properties of these materials can be tailored by an appropriate choice of the synthesis conditions. In this work, tannin–formaldehyde xerogels containing different amounts of surfactant and formaldehyde were synthesised in order to evaluate their effect on the porous structure and chemical composition. It was found that porosity and density depend greatly on the amount of surfactant. The lowest density and highest porosity values −0.34 g/cm3 and 78%, respectively-were obtained by adding 10 wt.% of surfactant. It was also found that S-doped carbon xerogels can be easily synthesized due to the strong affinity between the carbon in the structure and the sulphur from the surfactant. Furthermore, statistical analysis showed that there is interdependence between the effect of formaldehyde and the surfactant, especially in the case of volume and pore size. Hence, the choice of the appropriate surfactant-formaldehyde concentration is essential for controlling the formation of the porous polymeric structure.Financial support from the Ministerio de Economía y Competitividad of Spain MINECO (under Projects MAT2011-23733, IPT-2012-0689-420000 and CTQ2013-49433-EXP) is greatly acknowledged. NRR is also grateful to MINECO for her predoctoral research grant. The French authors also gratefully acknowledge the financial support of the CPER 2007–2013 “Structuration du Pô le de Compé titivité Fibres Grand'Est” (Competitiveness Fibre Cluster), through local (Conseil Général des Vosges), regional (Région Lorraine), national (DRRT and FNADT) and European (FEDER) funds.Peer reviewe

バイオマスガス化におけるタールの触媒的除去及び水素の生産

筑波大学 (University of Tsukuba)201

Removing mercury from aqueous solution using sulfurized biochar and associated mechanisms

Biochar has been used to remove heavy metals from aqueous solutions. In this study, a sulfurized wood biochar (SWB) by direct impregnation with elemental sulfur was produced and evaluated along with pristine wood biochar (WB) for adsorption characteristics and mechanism of mercury. Mercury adsorption by WB and SWB was well described by Langmuir model and pseudo second order model and the maximum adsorption capacities of WB and SWB were 57.8 and 107.5 mg g−1, respectively. Intraparticle diffusion model showed that mercury adsorption was fast due to boundary layer and slow adsorption due to diffusion into biochar pores. Although, mercury adsorption by both WB and SWB was predominantly influenced by the pH, temperature, salt concentration, and biochar dosage, the SWB showed a relatively stable mercury adsorption compared to WB under different conditions, suggesting the strong affinity of SWB for mercury. The XPS analysis showed different adsorption mechanisms of mercury between WB and SWB. In particular, mercury adsorption in WB was due to Hg-Cπ bond formation and interaction with carboxyl and hydroxyl groups, whereas in SWB it is primarily due to mercury interaction with C-SOx-C and thiophenic groups in addition to Hg-Cπ bond formation and interaction with carboxyl groups. The SEM-EDS mapping also demonstrated that mercury in SWB was related to carbon, oxygen and sulfur. Overall, the sulfurized biochar was effective for removing mercury from aqueous solution, and its direct production through pyrolysis with elemental sulfur impregnation of wood chips could make it an economic option as absorbent for treating mercury-rich wastewater

Biochar production, activation, and applications: A comprehensive technical review

\ua9 2025 The Authors. Our planet has been facing critical challenges since the late 20th century, including climate change, resource shortages, environmental degradation and pollution, demanding urgent and sustainable solutions. Biochar, a carbon-rich material produced via biomass pyrolysis, has gained attention for its great potentials in environmental remediation, pollutant removals, carbon neutrality, soil amendment, building materials, and etc. The performance of biochar in these applications is closely linked to its physicochemical properties, which are influenced by the feedstock and the preparation/activation methods. This paper reviews a wide range of biochar produced from various feedstocks, and the associated performance in different applications. Advanced characterisations are discussed to unveil the fundamental mechanisms and provide insights for further improvement and optimization. The techno-economic analysis evaluates the feasibility, challenges, and opportunities for scaling up and adopting biochar in potential applications. By focusing on biochar\u27s multifunctionality and sustainability, this paper provides a reference for future research on developing biochar as a green technology with environmental and economic benefits

"Cooking carbon in a solid salt": Synthesis of porous heteroatom-doped carbon foams for enhanced organic pollutant degradation under visible light

Porous heteroatom-doped carbons are desirable for catalytic reactions due to their tunable physicochemical properties, low cost and metal-free nature. Herein, we introduce a facile general bottom-up strategy, so-called "cooking carbon in a solid salt", to prepare hierarchically porous heteroatom-doped carbon foams by using poly(ionic liquid) as precursor and common inorganic salts as structural template. The obtained carbon foams bear micro-/meso-/macropores, large specific surface area and rich nitrogen dopant. The combination of these favorable features facilitates the catalytic degradation of aqueous organic pollutants by persulfate under visible light irradiation, in which they prevail over the state-of-the-art metal-/carbon-based catalysts.Comment: 31 pages, 24 figure