Showing papers on "Antimony published in 2021"

Atomically dispersed antimony on carbon nitride for the artificial photosynthesis of hydrogen peroxide

Abstract: Artificial photosynthesis offers a promising strategy to produce hydrogen peroxide (H2O2)—an environmentally friendly oxidant and a clean fuel. However, the low activity and selectivity of the two-electron oxygen reduction reaction (ORR) in the photocatalytic process greatly restricts the H2O2 production efficiency. Here we show a robust antimony single-atom photocatalyst (Sb-SAPC, single Sb atoms dispersed on carbon nitride) for the synthesis of H2O2 in a simple water and oxygen mixture under visible light irradiation. An apparent quantum yield of 17.6% at 420 nm together with a solar-to-chemical conversion efficiency of 0.61% for H2O2 synthesis was achieved. On the basis of time-dependent density function theory calculations, isotopic experiments and advanced spectroscopic characterizations, the photocatalytic performance is ascribed to the notably promoted two-electron ORR by forming μ-peroxide at the Sb sites and highly concentrated holes at the neighbouring N atoms. The in situ generated O2 via water oxidation is rapidly consumed by ORR, leading to boosted overall reaction kinetics. Hydrogen peroxide is an interesting target for artificial photosynthesis, although its actual production via the two-electron oxygen reduction reaction remains limited. Now, a carbon nitride-supported antimony single atom photocatalyst has been developed with a superior performance for this process.

Direct Hydrothermal Deposition of Antimony Triselenide Films for Efficient Planar Heterojunction Solar Cells

Abstract: Antimony selenide (Sb2Se3) has attracted increasing attention in photovoltaic applications due to its unique quasi-one-dimensional crystal structure, suitable optical band gap with a high extinction coefficient, and excellent stability. As a promising light-harvesting material, the available synthetic methods for the fabrication of a high-quality film have been quite limited and seriously impeded both the fundamental study and the efficiency improvement. Here, we developed a facile and low-cost hydrothermal method for in situ deposition of Sb2Se3 films for solar cell applications. In this process, we apply KSbC4H4O7 and Na2SeSO3 as the antimony and selenium sources, respectively, in which thiourea (TU) serves as an additive to suppress the formation of Sb2O3 impurities. As a result, improved phase purity and enhanced crystallinity of the Sb2Se3 film are thus obtained, along with decreased trap states. Finally, the planar heterojunction Sb2Se3 solar cell delivered a power conversion efficiency of 7.9%, which is thus far the highest reported efficiency among solution-processed Sb2Se3 solar cells. This simple procedure and efficiency achievement demonstrate the great potential of the hydrothermal deposition process for the fabrication of high-efficiency Sb2Se3 solar cells.

Active phases for high temperature Fischer-Tropsch synthesis in the silica supported iron catalysts promoted with antimony and tin

Abstract: Fischer-Tropsch synthesis provides an important opportunity for utilization of biomass and plastic waste. Iron catalysts are the catalysts of choice for light olefin synthesis using Fischer-Tropsch reaction. In this paper, we investigate strong promoting effects of antimony and tin on the catalytic performance of silica supported iron Fischer-Tropsch catalysts using a combination of advanced and in-situ techniques. The catalyst doping with these elements added via impregnation results in a major increase in the reaction rate and much better catalyst stability. No enhancement of iron dispersion was observed after the promotion, while somewhat higher extent of iron carbidization was observed in the antimony promoted catalysts. Iron-bismuth bimetallic nanoparticles are detected by several techniques. In the working catalysts, the promoters are located in close proximity to the iron nanoparticles. The promotion leads to the 7-10 times increase in the intrinsic activity of iron surface sites due to their interaction with the promoters.

A review of the environmental chemical behavior, detection and treatment of antimony

Abstract: Antimony (Sb), a toxic metalloid element, is located in the Group VA of the fifth period of the periodic table of elements. At present, with the wide use of antimony containing products in the world and the corresponding mining activities, a large number of antimony containing waste generated in these processes has also been released to the environment, resulting in antimony pollution has become a problem that cannot be ignored. People exposed to high concentrations of antimony will produce a series of health risks, which may lead to vomiting, diarrhea, rash and other diseases, and even cancer. Antimony in the environment comes from natural processes (ore weathering, volcanic activity) and human activities (mining and smelting, use of antimony containing products, fossil fuel combustion, etc.). Similar to many elements, the toxicity of antimony is closely related to its chemical form, and the toxicity of Sb(III) is much higher than Sb(V). Antimony exists in various chemical forms in the environment (mainly Sb(III) and Sb(V)), and its environmental chemical behavior is easily affected by various environmental factors. Redox conditions can change the chemical form of antimony and affect its migration and transformation in environmental media. Once the antimony minerals are oxidized in contact with the air, antimony will be released in a dissolved state, and then attached to the surface of various solid particles in the tailings in the form of adsorption. It is easy to migrate and diffuse to the surrounding environment under the leaching of surface water, and absorbed by plant roots. In addition, this review also emphasizes the detection methods of antimony, in which the development of combined technology is an increasingly attractive research field in antimony speciation analysis. Finally, we provide several commonly used Sb removal technologies, and critically analyze the remarkable characteristics and removal mechanism of these technologies, hoping to provide reference for the treatment and research of antimony pollution.

Suppressing the Trapping Process by Interfacial Charge Extraction in Antimony Selenide Heterojunctions

Abstract: The efficiency of antimony selenide (Sb2Se3) solar cells has been improved from 10% within only 7 years, but fundamental properties at the heterojunction interface such as the charge carrie...

Characterization and physicochemical aspects of novel cellulose-based layered double hydroxide nanocomposite for removal of antimony and fluoride from aqueous solution.

Abstract: A series of novel adsorbents composed of cellulose (CL) with Ca/Al layered double hydroxide (CCxA; where x represent the Ca/Al molar ratio) were prepared for the adsorption of antimony (Sb(V)) and fluoride (F−) ions from aqueous solutions. The CCxA was characterized by Fourier-transform infrared spectroscopy (FTIR), Brunauer–Emmett–Teller (BET), elemental analysis (CHNS/O), thermogravimetric analysis (TGA-DTA), zeta potential, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) analysis. The effects of varying parameters such as dose, pH, contact time, temperature and initial concentration on the adsorption process were investigated. According to the obtained results, the adsorption processes were described by a pseudo-second-order kinetic model. Langmuir adsorption isotherm model provided the best fit for the experimental data and was used to describe isotherm constants. The maximum adsorption capacity was found to be 77.2 and 63.1 mg/g for Sb(V) and F−, respectively by CC3A (experimental conditions: pH 5.5, time 60 min, dose 15 mg/10 mL, temperature 298 K). The CC3A nanocomposite was able to reduce the Sb(V) and F− ions concentration in synthetic solution to lower than 6 μg/L and 1.5 mg/L, respectively, which are maximum contaminant levels of these elements in drinking water according to WHO guidelines.

Highly Efficient Light-Emitting Diodes Based on an Organic Antimony(III) Halide Hybrid

Abstract: As low-dimensional lead-free hybrids with higher stability and lower toxicity than those of three-dimensional lead perovskites, organic antimony(III) halides show great application potential in opt-electronic field owing to diverse topologies along with exceptional optical properties. We report herein an antimony(III) hybrid (MePPh3 )2 SbCl5 with a zero-dimensional (0D) structure, which exhibits brilliant orange emission peaked at 593 nm with near-unity photoluminescent quantum yield (99.4 %). The characterization of photophysical properties demonstrates that the broadband emission with a microsecond lifetime (3.24 μs) arises from self-trapped emission (STE). Electrically driven organic light-emitting diodes (OLEDs) based on neat and doped films of (MePPh3 )2 SbCl5 were fabricated. The doped devices show significant improvement in comparison to non-doped OLEDs. Owing to the much improved surface morphology and balanced carrier transport in light-emitting layers of doped devices, the peak luminance, current efficiency (CE) and external quantum efficiency (EQE) are boosted from 82 cd m-2 to 3500 cd m-2 , 1.1 cd A-1 to 6.8 cd A-1 , and 0.7 % to 3.1 % relative to non-doped devices, respectively.

Selective extraction of arsenic and antimony from gold-bearing sludge using two-stage alkaline leaching

Abstract: In gold smelting industry, coexisting of arsenic (As) and antimony (Sb) in gold-bearing sludge is a serious issue for the smelting process. This study employed a two-stage leaching methods to selective extract arsenic and antimony from gold-bearing sludge. Arsenic was firstly removed through NaOH leaching, following by Na2S-NaOH leaching to remove antimony in the atmospheric conditions. The first step results show that more than 96% of arsenic can be removed under the conditions of 2 mol/L NaOH, the ratio of liquid to solid (L/S) of 5, 60 °C, 400 rpm, 3 h. Meanwhile, the antimony dissolved in the solution is converted into the residue as the state of NaSb(OH)6 during this process. After Na2S-NaOH leaching, the antimony leaching extent is 97.2% during the condition of 2.5 mol/L Na2S, 0.125 mol/L NaOH, L/S = 5, 70 °C and 6 h. In addition, the vulcanization of copper was found in the Na2S-NaOH leaching process, and the CuS appeared in the leaching residue. The results prove that the NaOH leaching following by Na2S-NaOH leaching can selectively extract arsenic and antimony from gold-bearing sludge in the atmospheric conditions.

Three-dimensional antimony sulfide anode with carbon nanotube interphase modified for lithium-ion batteries

Abstract: Antimony sulfide (Sb2S3) is a promising anode for lithium-ion batteries due to its high capacity and vast reserves. However, the low electronic conductivity and severe volume change during cycling hinder its commercialization. Herein our work, a three-dimensional (3D) Sb2S3 thin film anode was fabricated via a simple vapor transport deposition system by using natural stibnite as raw material and stainless steel fiber-foil (SSF) as 3D current collector, and a carbon nanotube interphase was introduced onto the film surface by a simple dropping-heating process to promote the electrochemical performances. This 3D structure can greatly improve the initial coulombic efficiency to a record of 86.6% and high reversible rate capacity of 760.8 mAh·g−1 at 10 C. With carbon nanotubes interphase modified, the Sb2S3 anode cycled extremely stable with high capacity retention of 94.7% after 160 cycles. This work sheds light on the economical preparation and performance optimization of Sb2S3-based anodes.