This paper explores the effects of concentration of acid activation on the properties of rare earth tailings catalyst. The results show that the denitration activity of rare earth tailings catalyst is enhanced by acid activation. The best denitration activity of catalyst, activated by sulfuric acid of 8 mol/L, is 86%.
Carbon nanotubes (CNTs) are an excellent electrode material for capacitive deionization (CDI), due to their excellent electronic conductivity and outstanding chemical/physical stability. Their powder form and easy aggregation, however, have greatly limited their practical CDI performance. Aiming to address this issue, the authors report a freestanding CNT film which was fabricated by floating-catalyst chemical vapor deposition, as a binder-free electrode for CDI. By simply adjusting the pyrrole content in the precursor, the morphology of the resulting CNT film can be tuned to meet the requirements of CDI. In the presence of 2 wt.% pyrrole, the CNT film with a mesoporous structure exhibited a large specific surface area of 198 m 2 /g and an increased electric double-layer capacity (40 F/g), which is more than two times as large as that of the pristine CNT film. Due to these merits, the electrosorption capacity for sodium chloride (NaCl) of the CNT film electrode (11·39 mg/g) has been greatly improved compared with that of the pristine CNT film (4·52 mg/g), showing a good potential for large-scale practical CDI.
Y2O2S and Gd2O2S phosphor lattices activated with a range of Tb3+ concentrations have been successfully prepared as nanoparticles and their emission properties have been characterized using SEM, XRPD, photoluminescence spectroscopy and cathodoluminescence. 5D3–5D4 cross relaxation processes between Tb3+ cations were observed in both Y2O2S and Gd2O2S as a function of Tb3+ concentration. In the Y2O2S host lattice, the predominant emission colour shifts from blue to green with increased Tb3+ concentration. In contrast, green emission is always predominant in Gd2O2S at Tb3+ concentrations from 0.1 mol% to 5 mol%. This finding is explained in accordance with previous reports on the bulk materials that found the Gd2O2S lattice has a lower charge transfer state than the Y2O2S host lattice.
Recently, an sp2 hybridized planar two-dimensional graphene-based carbon allotrope composed of tetra-penta-octagonal rings has attracted considerable interest. The electronic structures and transport properties of zigzag-edged tetra-penta-octagonal-graphene nanoribbons (TPO-ZGNRs) modified via boundary passivation were investigated using density functional theory and the non-equilibrium Green's function. TPO-ZGNRs were passivated with H, 2H, O, OH, and Cl on the edge to produce TPO-ZGNRs-X (X=H, 2H, O, OH, and Cl). TPO-ZGNRs-H exhibits metallic properties regardless of the nanoribbon width and exists in the non-magnetic state. Although TPO-ZGNRs-OH and TPO-ZGNRs-Cl remain metallic, TPO-ZGNRs-2H and TPO-ZGNRs-O are semiconductors. In addition, the current–voltage curves of three TPO-ZGNRs-X (X=H, OH, and Cl) homojunction device models contain a negative differential resistance region. Notably, the heterojunction device model in which TPO-ZGNRs are passivated with H and O atoms at different edge regions has negative differential resistance and rectification characteristics. This study is expected to facilitate the development of new carbon materials.
Continuous Fe nanoparticles (NPs)/carbon nanotube (CNTs) composite films have been fabricated with the CVD gas flow reaction using ferrocene as a catalyst and ethanol as a carbon precursor.
In article number 2001265, Dong Su, Huiming Ji, Ji Liang, and co-workers fabricate a flexible film using pre-assembled graphene/SnS2 microblocks as parents bridged by graphene. The film possesses a 3D-porous graphene framework and a structure of SnS2 nanocrystals chemically bonded on graphene, which integrates fast ion/electron diffusion with robust utilization of SnS2, thus leading to high areal capacity and high rate performance as flexible SIBs anodes.
A SiOC nanolayer wrapped 3D interconnected GNS conductive framework contributed to the best ever reported high-performance for SiOC-based anode materials.
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