A method for preparing an iron sulfide (FeS.sub.2) with selective and high purity by a simple process, a positive electrode for a lithium secondary battery including the iron sulfide (FeS.sub.2) prepared therefrom, which can adsorb the lithium polysulfide produced during the charging and discharging process of the lithium secondary battery, thereby increasing the charging and discharging efficiency of the battery and improving its lifetime characteristics; and a lithium secondary battery provided with the same.

A method for preparing an iron sulfide (FeS.sub.2) with selective and high purity by a simple process, a positive electrode for a lithium secondary battery including the iron sulfide (FeS.sub.2) prepared therefrom, which can adsorb the lithium polysulfide produced during the charging and discharging process of the lithium secondary battery, thereby increasing the charging and discharging efficiency of the battery and improving its lifetime characteristics; and a lithium secondary battery provided with the same.

A composite sulfide electrode and a manufacturing method therefor are disclosed. A method for manufacturing a composite sulfide electrode comprises the steps of: preparing a mixed solution of polyacrylonitrile (PAN) and a metallic oxide; stirring the prepared mixed solution; electrospinning the stirred mixed solution to prepare a wire-type precursor bearing a metallic oxide in PAN; drying the prepared wire-type precursor; mixing the dried wire-type precursor and a sulfur powder; and injecting a gas to the mixture of the wire-type precursor and the sulfur powder to sulfurize the wire-type precursor.

Methods and apparatus for controlling odor of wastewater are described. An example method includes dispensing a solution in wastewater. The solution comprises an iron-nitrate compound mixed in water. In some examples, the iron-nitrate compound is ferric nitrate and/or ferrous nitrate. In some examples, the solution further includes an iron ion source different from the iron-nitrate compound, such as an iron salt like ferrous sulfate, ferrous chloride, or the like. The dispensing can be by using a feeding station in a wastewater collection system.

The present disclosure relates to compositions, systems and methods for removing iron sulfide scale from a solid object, such as an oilfield component. The compositions include a carbon-carbon (CC) double bond with an electron withdrawing group bonded to at least one of the double-bonded carbons.

Systems and methods are provided for the fabrication and manufacture of efficient, low-cost p-n heterojunction pyrite solar cells. The p-n heterojunction pyrite solar cells can include a pyrite thin cell component, a window layer component, and a top surface contact component. The pyrite thin cell component can be fabricated from nanocrystal paint deposited onto metal foils or microcrystalline pyrite deposited onto foil by chemical vapor deposition. A method of synthesizing colloidal pyrite nanocrystals is provided. Methods of manufacturing the efficient, low-cost p-n heterojunction pyrite solar cells are also provided.

Systems and methods are provided for the fabrication and manufacture of efficient, low-cost p-n heterojunction pyrite solar cells. The p-n heterojunction pyrite solar cells can include a pyrite thin cell component, a window layer component, and a top surface contact component. The pyrite thin cell component can be fabricated from nanocrystal paint deposited onto metal foils or microcrystalline pyrite deposited onto foil by chemical vapor deposition. A method of synthesizing colloidal pyrite nanocrystals is provided. Methods of manufacturing the efficient, low-cost p-n heterojunction pyrite solar cells are also provided.

A liquid suspension comprised of ferrous sulfide particles and method of using the same for the removal of selenium from industrial gas. Said liquid suspension may be (1) directly injected, or (2) coated onto or into a substrate and then injected into an industrial gas containing selenium to remove said selenium from the industrial gas stream in a dry scrubber system. Said liquid suspension of ferrous sulfide particles may also be used to remove selenium contained in industrial gases in a wet scrubber system.

A sulfidic complexing agent is disclosed that includes a suspension or a solution formed by a reaction between a water-soluble metal compound and a water-soluble sulfidic compound. The sulfidic complexing agent has a pH of from about 5 to about 11 and a molar ratio of metal to sulfur of from about 0.1 to about 1,000. The sulfidic complexing agent is useful for removing elemental mercury from a hydrocarbon fluid by contacting the hydrocarbon fluid with the sulfidic complexing agent. The molar ratio of sulfur in the sulfidic complexing agent to mercury in the hydrocarbon fluid is from about 50 to about 2,500. Also disclosed is a method for concurrently transporting and removing a trace amount of volatile mercury in a CO.sub.2-containing natural gas stream extracted from a subterranean formation. The natural gas stream is transported in a pipeline into which the sulfidic complexing agent is injected. Also disclosed is a method for capturing gas phase elemental mercury from a gas stream in the overhead section of a crude oil distillation unit by contacting the gas stream with the sulfidic complexing agent in the overhead section of the distillation unit to form a treated gas stream.

Systems and methods of synthesizing nanoparticles on substrates using rapid, high temperature thermal shock. A method involves depositing micro-sized particles or salt precursors on a substrate, and applying a rapid, high temperature thermal pulse or shock to the micro-sized particles or the salt precursors and the substrate to cause the micro-sized particles or the salt precursors to become nanoparticles on the substrate. A system may include a rotatable member that receives a roll of a substrate sheet having micro-sized particles or salt precursors; a motor that rotates the rotatable member so as to unroll consecutive portions of the substrate sheet from the roll; and a thermal energy source that applies a short, high temperature thermal shock to consecutive portions of the substrate sheet that are unrolled from the roll by rotating the first rotatable member. Some systems and methods produce nanoparticles on existing substrate. The nanoparticles may be metallic, ceramic, inorganic, semiconductor, or compound nanoparticles. The substrate may be a carbon-based substrate, a conducting substrate, or a non-conducting substrate. The high temperature thermal shock process may be enabled by electrical Joule heating, microwave heating, thermal radiative heating, plasma heating, or laser heating.