Recent advances in the synthesis and lithium storage properties of silicon oxide-based anode materials.

Nanostructured copper sulfide synthesized with the assistance of surfactant with nanoscale particle size and high Brunauer-Emmett-Teller surface area was for the first time applied for the capture of elemental mercury (Hg) from coal combustion flue gas. The optimal operation temperature of nano-CuS for Hg adsorption is 75 °C, which indicates that injection of the sorbent between the wet flue gas desulfurization and the wet electrostatic precipitator systems is feasible. This assures that the sorbent is free of the adverse influence of nitrogen oxides. Oxygen (O) and sulfur dioxide exerted a slight influence on Hg adsorption over the nano-CuS. Water vapor was shown to moderately suppress Hg capture efficiency via competitive adsorption. The simulated adsorption capacities of nano-CuS for Hg under pure nitrogen (N), N + 4% O, and simulated flue gas reached 122.40, 112.06, and 89.43 mgHg/g nano-CuS, respectively. Compared to those of traditional commercial activated carbons and metal sulfides, the simulated adsorption capacities of Hg over the nano-CuS are at least an order of magnitude higher. Moreover, with only 5 mg loaded in a fixed-bed reactor, the Hg adsorption rate reached 11.93-13.56 μg/g min over nano-CuS. This extremely speedy rate makes nano-CuS promising for a future sorbent injection technique. The anisotropic growth of nano-CuS was confirmed by X-ray diffraction analysis and provided a fundamental aspect for nano-CuS surface reconstruction and polysulfide formation. Further X-ray photoelectron spectroscopy and Hg temperature-programmed desorption tests showed that the active polysulfide, S-S dimers, and copper-terminated sites contributed primarily to the extremely high Hg adsorption capacity and rate. With these advantages, nano-CuS appears to be a highly promising alternative to traditional sorbents for Hg capture from coal combustion flue gas.

Environmentally benign zinc sulfide (ZnS), consisting entirely of “active” sites, has shown promising efficiency for capturing mercury from flue gas in recent experimental studies. In this work, the binding mechanism of Hg0 on the ZnS(110) surface was investigated by the density functional theory (DFT) method. Meanwhile, the binding of two additional mercury forms, HgCl and HgCl2, and three essential flue gas components, H2O, SO2, and HCl, and their further effects on the strength of Hg0 binding on the ZnS(110) surface were also evaluated. The results showed that, consistent with experimental observations, Hg0 can be chemisorbed on the ZnS(110) surface with binding energies (BEs) as high as −87.80 kJ/mol. The enhanced electrostatic characteristics on the activated surface, especially the Zn sites, are beneficial to exciting the outer-shell electrons of Hg0 and thereby enhancing the binding strength of the material. HgCl and HgCl2 were found to be chemisorbed with the highest BEs of −174.33 and −132.79 kJ/mol, respectively. Moreover, H2O was found to have a positive effect on Hg0 binding, whereas SO2 and HCl have negligible effects. Our theoretical calculations demonstrate that ZnS has great potential to serve as a novel sorbent for the efficient removal of mercury from coal-combustion flue gas.

Rattle-type Fe3O4@CuS synthesized using a two-step method was applied for elemental mercury (Hg0) adsorption in coal combustion flue gas for the first time. The Fe3O4 with strong magnetization was an ideal candidate as a core to make the sorbent recyclable, while the stabilized ultrathin CuS shell assured that the Fe3O4@CuS had a higher Brunauer–Emmett–Teller (BET) surface area with more exposed active sites and stronger magnetization. The optimal operating temperature of 75 °C allowed for the injection of the sorbent between the wet desulfurization (WFGD) and wet electrostatic precipitator (WESP), which removed the detrimental influence of nitrogen oxides. Simulated flue gas (SFG) in this section showed a slight inhibitive effect on Hg0 adsorption over the Fe3O4@CuS, mainly due to the presence of water vapor (H2O). The inhibition of H2O was proven to be the result of an active site prevention effect instead of the widely recognized competitive adsorption effect. The adsorption capacity and rate of the Fe3O4@CuS for Hg0 capture reached 80.73 mg g–1 and 13.22 μg (g min)−1, which were the highest values among the magnetic sorbents currently reported for Hg0 removal from coal combustion flue gas. These properties allowed the sorbent to maintain a 100% Hg0 capture efficiency for more than 20 h with only a 50 mg dosage when no regeneration step was applied. Meanwhile, the contacting time between the sorbent and Hg0 was generally less than 5 s in a typical sorbent injection process. Polysulfides dominated the capturing process and primarily contributed to the extremely high adsorption capacity/rate. A multistep reaction mechanism was proposed to explain the Hg0 adsorption over Fe3O4@CuS. At the first stage, polysulfide participated in Hg0 adsorption as the most active component and was consumed rapidly. After that, S–S dimers, sulfides, and even copper-terminated sites functioned as the adsorption centers. The as-formed mercury–copper (Hg–Cu) amalgam was transformed into mercury sulfide (HgS), a process that was dependent on the extent of the saturation of sulfide sites. With these advantages, Fe3O4@CuS is a promising, cost-effective, highly recyclable, and efficient alternative to the traditional activated carbon for capturing Hg0 in coal combustion flue gases.

Double shell FeOOH/PPy on a diatomite ternary complex was assembled via two-step hydrothermal and in situ polymerization routes.

Porous yolk–shell structured Nb2O5 enables a Nb2O5//activated carbon lithium-ion capacitor to exhibit superior energy density and cycling stability.

A key challenge in elemental mercury (Hg 0 ) decontamination from flue gas lies in the design of a sorbent with abundant reactive adsorption sites that exhibit high affinity toward Hg 0 to simultaneously achieve rapid capture and large capacity. Herein, zeolitic imidazolate framework-8 (ZIF-8) supported copper selenide (CuSe) nanocomposites are synthesized by a newly designed two-step surfactant-assisted method. The as-prepared CuSe/ZIF-8 with CuSe to ZIF-8 mass ratio of 80% (0.8NC-ZIF) exhibits unparalleled performance toward Hg 0 adsorption with equilibrium capacity and average rate reaching 309.8 mg g −1 and 105.3 µg g −1 min −1 , respectively, surpassing all reported metal sulfides and traditional activated-carbon-based sorbents. The impressive performance of 0.8NC-ZIF for Hg 0 immobilization is primarily attributed to the adequate exposure of the Se-terminated sites with high affinity toward Hg 0 resulted from the layered structure of CuSe. The adsorbed mercury selenide exhibits even higher stability than the most stable natural mercury ore-that is, mercury sulfide-hence minimizing its environmental impact when the CuSe/ZIF-8 sorbent is dumped. This work provides a new mindset for future design of sorbents for efficient Hg 0 capture from industrial flue gas. The results also justify the candidature of CuSe/ZIF to be applicable for mercury pollution remediation in real-world conditions.

Aqueous potassium-ion batteries (AKIBs), utilizing fast diffusion kinetics of K+ and abundant electrode resources, are an emerging technology offering high power density and low cost.