Optimization of synergistic capturing platinum group metals by Fe-Sn and its mechanism.

Platinum group metals (PGMs) are strategic metals. Auto-exhaust catalysts are their main application fields. The recovery of PGMs from spent auto-exhaust catalysts has remarkable economic value and strategic significance. Aiming at the problems of ferrosilicon generation for Fe capturing and subsequent oxygen blowing to remove iron with high energy consumption and heat release, a technology of Fe-Sn synergistic capturing PGMs was proposed. Taking full the advantage of the lower melting point of Fe-Sn alloy (<1200 °C) and its unique affinity for PGMs, the PGMs were captured at approximate 1400 °C with Fe-Sn as the collector. In experiment, 500 g of spent auto-exhaust catalysts were employed to minimize error and approximate industrial production. The mechanism of Fe-Sn synergistic capturing PGMs was elucidated. The generation of Fe-Sn-PGMs alloy lowered the activity of [PGMs] in the system, accelerated the reduction of the PGMs oxides and promoted the alloying of [PGMs]. Therefore, Fe-Sn synergistic capturing PGMs was realized. The inability of Si to enter the alloy phase was confirmed by theoretical calculations, avoiding the generation of ferrosilicon. The effects of basicity, CaF2, m(Fe)/m(Sn) and the amount of collector on capturing PGMs were optimized. Under the optimized conditions (basicity R = 1.1, spent auto-exhaust catalysts 70 wt%, CaO 30 wt%, B2O3 10 wt%, CaF2 7 wt%, m(Fe)/m(Sn) = 1/1 and the collector 15 wt%), the content of PGMs in the slag phase was 2.46 g/t. It is feasible to remove Fe and Sn by oxidation to achieve the purpose of PGMs enrichment. This technology offers guidance on the safe, environmentally sound, and efficient disposal of spent auto-exhaust catalysts, promoting the sustainable development of PGMs.

Efficient and comprehensive recycling of valuable components from scrapped Si-based photovoltaic panels.

The increasing scrapped Si-based photovoltaic (PV) panels has become an urgent problem, and their disposal is essential for resources utilization and environment issues. This paper proposes a comprehensive process for recycling of discarded silicon-based PV panels economically, environmentally, and efficiently. Based on the thermal properties of ethylene vinyl acetate (EVA), they are removed from the discarded PV panels at 600 °C with heating rate of 5 °C/min and maintain for one hour. The glass, solar cells, and copper strips were separated after heat treatment. Simultaneously, the solar cells were crushed into powder. Nitric acid was used to recover silver from the solar cell powder, while most of the metal impurities such as Mg, Ti and Al, were removed as well. The leaching efficiency of silver was over 96 % under the optimized conditions: HNO3 of 4.0 mol/L, liquid-to-solid ratio of 10:1, temperature of 50 °C for 80 min. Regarding the copper strips, they were sequentially treated with 0.5 mol/L CH3COOH and NaOH solution to remove the oxides of Pb and Sn on their surface. Subsequently, they were placed into the solution of 1.0 mol/L CuSO4 with pH of 2 âˆ¼ 3 to eliminate Pb and Sn. This article provides significant reference for the recycling of Si-based PV panels.

Total Flavonoids from Camellia oleifera Alleviated Mycoplasma pneumoniae-Induced Lung Injury via Inhibition of the TLR2-Mediated NF-κB and MAPK Pathways.

Mycoplasma pneumoniae (M. pneumoniae) is an atypical bacterial pathogen responsible for community-acquired pneumonia primarily among school-aged children and young adults. Camellia oleifera (C. oleifera) has been used as a medicinal and edible plant in China for centuries, the constituents from which possessed various bioactivities. Notably, flavonoids existing in residues of C. oleifera defatted seeds exhibited significant anti-inflammatory activities. In the present study, we investigated the impact of total flavonoids from C. oleifera (TFCO) seed extract on M. pneumoniae pneumonia. TFCO was obtained using multiple column chromatography methods and identified as kaempferol glycosides via UPLC-HRESIMS. In a M. pneumoniae pneumonia mouse model, TFCO significantly reduced the lung damage, suppressed IL-1ß, IL-6, and TNF-α production, and curbed TLR2 activation triggered by M. pneumoniae. Similarly, in RAW264.7 macrophage cells stimulated by lipid-associated membrane proteins (LAMPs), TFCO suppressed the generation of proinflammatory cytokines and TLR2 expression. Moreover, TFCO diminished the phosphorylation of IκBα, JNK, ERK, p38, and p65 nuclear translocation in vitro. In conclusion, TFCO alleviated M. pneumoniae-induced lung damage via inhibition of TLR2-mediated NF-κB and MAPK pathways, suggesting its potential therapeutic application in M. pneumoniae-triggered lung inflammation.

High-Performance Uncooled Mid-Infrared Detector Based on a Polycrystalline PbSe/CdSe Heterojunction.

Developing high-performance, uncooled mid-wavelength infrared (MWIR) detectors is a challenging task due to the inherent physical properties of materials and manufacturing technologies. In this study, we designed and manufactured an uncooled polycrystalline PbSe/CdSe heterojunction photovoltaic (PV) detector through vapor physical deposition. The resulting 10 µm × 10 µm device exhibited a peak detectivity of 7.5 × 109 and 3 × 1010 cm·Hz1/2·W-1 at 298 and 220 K, respectively, under blackbody radiation. These values are comparable to those of typical PbSe photoconductive detectors fabricated through standard chemical bath deposition. Additionally, the sensitization-free process used to create these PbSe/CdSe PV detectors allows for high replicability and yield, making them promising candidates for low-cost, high-performance, uncooled MWIR focal plane array imaging in commercial applications.

Epitaxial CdSe/PbSe Heterojunction Growth and MWIR Photovoltaic Detector.

A novel Epitaxial Cadmium Selenide (CdSe) on Lead Selenide (PbSe) type-II heterojunction photovoltaic detector has been demonstrated by Molecular Beam Epitaxy (MBE) growth of n-type CdSe on p-type PbSe single crystalline film. The use of Reflection High-Energy Electron Diffraction (RHEED) during the nucleation and growth of CdSe indicates high-quality single-phase cubic CdSe. This is a first-time demonstration of single crystalline and single phase CdSe growth on single crystalline PbSe, to the best of our knowledge. The current-voltage characteristic indicates a p-n junction diode with a rectifying factor over 50 at room temperature. The detector structure is characterized by radiometric measurement. A 30 µm × 30 µm pixel achieved a peak responsivity of 0.06 A/W and a specific detectivity (D*) of 6.5 × 108 Jones under a zero bias photovoltaic operation. With decreasing temperature, the optical signal increased by almost an order of magnitude as it approached 230 K (with thermoelectric cooling) while maintaining a similar level of noise, achieving a responsivity of 0.441 A/W and a D* of 4.4 × 109 Jones at 230 K.

Electrocatalysis CO2 to Tunable Syngas upon Fe Clusters Catalyst Dispersed on Bamboo-like NCTs.

Herein, we report a catalyst of Fe@NBCT with a high performance in electrocatalytic CO2 to syngas with tunable H2/CO ratio. Both in situ synchrotron radiation Fourier transform infrared spectra (SR-FTIR) and density functional theory (DFT) calculation proved that the differing N-doping carbon matrix and Fe nanoclusters (NCs) play dramatic roles in tuning the ratio of syngas during the electrocatalytic carbon dioxide reduction reaction (EC-CO2RR) process.

Enhanced performance in uncooled n-CdSe/p-PbSe photovoltaic detectors by high-temperature chloride passivation.

High-temperature chloride passivation (HTCP) was proposed to improve the crystalline quality and electrical properties of PbSe epitaxial films. The PL intensity of HTCP (111) PbSe epitaxial films exhibits a 14 times higher intensity than that of as-grown films, and a threefold increase in Hall mobility has been obtained after HTCP at 300 °C for 2 h. The improvement of optical and electrical properties is attributed to the high-temperature defect passivation induced by the HTCP process. The HTCP process of PbSe films was implemented in a CdSe/PbSe heterojunction PV detector, which exhibits a room temperature peak detectivity D* of 8.5 × 108 cm Hz1/2 W-1 in the mid-wavelength infrared region under blackbody radiation (227 °C), demonstrating potential applications in the fabrication of mid-infrared detectors and emitters.

Reduction for heavy metals in pickling sludge with aluminum nitride in secondary aluminum dross by pyrometallurgy, followed by glass ceramics manufacture.

Secondary aluminum dross (SAD) from aluminum industry is classified as a hazardous solid waste due to containing aluminum nitride (AlN). In this work, AlN was first used to reduce heavy metals by pyrometallurgy. The reduction rates for iron, chromium and nickel were up to 90%, 80% and 100%, respectively. However, the reduction from AlN and oxygen oxidization of AlN occurred simultaneously. AlN which formed solid solution with alumina could reduce heavy metals, while the rest was oxidized by oxygen. In addition, the reduction rates for iron and chromium could be increased with increasing CaF2 from 6.7 to 9.0 wt%. CaF2 could decreased viscosity of molten slag, which favored the ion migration, and then increased the reduction rates. After the reduction, glass ceramics were manufactured from the molten slags. The bending strength, microhardness and alkali resistance of the glass ceramics were up to 77 MPa, 1011 HV and 98.7%, respectively. According to XRD and SEM results, glass ceramics with CaAl2SiO6 crystal phase, crosslinked network structure grains and smaller pores exhibited better bending resistance. In addition, glass ceramics with CaAl2SiO6 crystal phase possessed the highest microhardness and alkali resistance. After this process, hazardous pickling sludge and SAD were totally recycled.

Low-cost uncooled MWIR PbSe quantum dots photodiodes.

A mid-wave infrared (MWIR) uncooled PbSe-QDs/CdS p-n heterojunction photodiode has been fabricated using a wet-chemical synthesis route. This offers a low-cost alternative to traditional monocrystalline photodiodes relying on molecular beam epitaxy (MBE) technology. It was demonstrated that the post-annealing is critical to tailor the photoresponse wavelength and to improve the performance of photodiodes. After annealing at 673 K in air for 0.5 h, the ligand-free PbSe-QDs/CdS photodiode exhibits a MWIR spectral photoresponse with a cutoff wavelength of 4.2 µm at room temperature. Under zero-bias photovoltaic mode, the peak responsivity and specific detectivity at room temperature are 0.36 ± 0.04 A W-1 and (8.5 ± 1) ×108 cm Hz1/2 W-1, respectively. Temperature-dependent spectral response shows an abnormal intensity variation at temperatures lower than 200 K. This phenomenon is attributed to the band alignment transition from type II to type I, resulting from the positive temperature coefficient of PbSe. In addition, it was proved that In doped CdSe (CdSe:In) films could be used as a promising new candidate of infrared transparent conductive electrodes, paving the way for monolithic integration of uncooled low-cost MWIR photodiodes on Si readout circuitry.