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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, CaF 2 , 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%, B 2 O 3 10 wt%, CaF 2 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., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Concrete is the main ingredient in construction, but it inevitably fractures during its service life, requiring a large amount of cement and aggregate for maintenance. Concrete healing through biomineralization can repair cracks and improve the durability of concrete, which is conducive to saving raw materials and reducing carbon emissions. This paper reviews the biodiversity of microorganisms capable of precipitating mineralization to repair the concrete and their mineralization ability under different conditions. To better understand the mass transfer process of precipitates, two biomineralization mechanisms, microbially-controlled mineralization and microbially-induced mineralization, have been briefly described. The application of microorganisms in the field of healing concrete, comprising passive healing and intrinsic healing, is discussed. The key insight on the interaction between cementitious materials and microorganisms is the main approach for developing novel self-healing concrete in the future to improve the corrosion resistance of concrete. At the same time, the limitations and challenges are also pointed out., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

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: HNO 3 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 CH 3 COOH 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 CuSO 4 with pH of 2 ∼ 3 to eliminate Pb and Sn. This article provides significant reference for the recycling of Si-based PV panels., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Inverse lithography technique (ILT) is a leading-edge method to improve the image fidelity of an advanced optical lithography system by performing pixel-wise optimization on the transmission function of photomask. However, traditional ILTs are computationally intensive, which limits their application in high volume manufacturing of integrated circuits. This paper proposes a model-driven graph convolutional network (MGCN) framework combined with the dense concentric circular sampling (DCCS) method to effectively improve computational efficiency and imaging fidelity of current ILTs. Firstly, the DCCS template is used to extract the geometric features from the layout pattern of integrated circuits, which are then input into a GCN-based encoder to predict the optimized mask pattern of the ILT. Then, a model-driven decoder based on the lithography imaging process is developed to retrieve the print image of the predicted ILT mask. By means of the cooperation between the encoder and decoder, an unsupervised training strategy is proposed to avoid the time-consuming labelling process of the training samples. With the help of the parallel computing under GPU framework, the well-trained encoder can make a fast prediction of ILT mask with high-fidelity image results. The results demonstrate the state-of-the-art performance of the proposed MGCN approach compared to some other comparative ILT methods.

Safety and efficient dispose of municipal solid waste incineration (MSWI) fly ash with high toxicity has emerged as a worldwide challenge. Vitrification provides the advantages of capacity reduction, detoxification, and solidification of heavy metals, which has the potential to dispose of hazardous waste on a large scale. Herein, co-vitrification of MSWI fly ash and bottom slag has been accomplished based on the characteristics of calcium and silicon composition. A novel approach for producing glass ceramic foams by alkaline activation-crystallization was developed to realize the disposal of the obtained glass. The effect of MSWI fly ash/bottom slag ratios on the glass network, crystallization ability of the basic glass, pore structure, and physical properties of the porous green body was investigated. The results revealed that with increasing MSWI fly ash proportion, the Si-O of [SiO 4 ] in the basic glass changed significantly and the crystallization ability steadily reduced. Si-O and Al-O in basic glass are easy to corrode under alkaline conditions, releasing Ca 2+ and forming a low solubility product, calcium silicate hydrate. When the crystallization temperature increases from 950 ℃ to 1150 ℃, it is more conducive to the precipitation of the gehlenite phase. Extending the crystallization time promotes three-dimensional growth of crystals that are coupled with each other to form a network structure and a multi-stage pore structure. The pore structure was developed with the help of NH 3 and H 2 generated by the secondary aluminum ash (SAA). Through the preparation of glass ceramic foams, the raw materials were detoxified. The toxic heavy metals showed extremely low leaching concentrations, which were smaller than the limit of TCLP. The prepared samples had 70.22-80.61% of porosity, 0.78-1.19 g/cm 3 of low bulk density, and 0.54-7.86 MPa of compressive strength., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

For nanofibrous aerogels, a three-dimensional porous structure with interwoven nanofibers as a pore wall has become an urgent demand, and it remains to be a challenge to ensure the mechanical stability and thermal insulation. Other than the reported nanofiber as raw materials to generate three-dimensional cellular nanofibrous aerogels, an alternative low-cost and facile procedure has been proposed here via tactfully utilizing polymer sponge as a template attached with reactive particles, followed by a carbothermal reduction process to realize nanowire growth and their replacement of the original framework. The resulting spongy aerogels with numerous interlaced SiC/Si 3 N 4 nanowires as a skeleton exhibit an ultrahigh porosity of 99.79%. Meanwhile, compressive elasticity after a compression at strain of 35% for 400 cycles, a low thermal conductivity of 23.19 mW/(m K), an excellent absorption capacity of 33.9-95.3 times for varied organic solvents removal, along with flexibility in shape design favored by the initial organic sponge make this nanofibrous aerogel an ideal material for heat shielding, absorption, or catalyst support.

This paper proposes a new method for producing nano-SrFe 12 O 19 powder by the citrate precursor route using solid waste as a source of iron. This solid iron-containing waste, which exists in the form of an oily sludge, is produced by a cold rolling mill. This sludge was first subjected to a process, including sulfuric acid leaching, oxidation, precipitation, and nitric acid leaching, to obtain an iron nitrate (Fe(NO 3 ) 3 ) solution. Next, the Fe(NO 3 ) 3 solution was mixed with a strontium nitrate (Sr(NO 3 ) 2 ) solution obtained by subjecting strontium carbonate to nitric acid leaching. Subsequently, citric acid, as chelating agent, and ammonia water, as precipitating agent, were added to the mixed solution to form a gel. The gel was dried and spontaneously combusted, then annealed at different temperatures for 2 h in flowing air. The effects of the Fe 3+ /Sr 2+ molar ratio and annealing temperature on the formation, morphology, and magnetic properties of SrFe 12 O 19 were investigated. The results showed that single-phase SrFe 12 O 19 powder was obtained by decreasing the Fe 3+ /Sr 2+ molar ratio from the stoichiometric value of 12 to 11.6 and increasing the annealing temperature to 1000 °C for 2 h. Adjustment of the Fe/Sr molar ratio to 12 and the annealing temperature to 900 °C enabled the magnetic properties to be optimized, including saturation magnetization (Ms) 80.2 emu/g, remanence magnetization (Mr) 39.8 emu/g, and coercive force (Hc) 6318 Oe.

A series of Mn-based catalysts were prepared by a wet impregnation method for the selective catalytic reduction (SCR) of NO with NH 3 . The Mn/Ti-Zr catalyst had more surface area, Lewis acid sites, and Mn 4+ on its surface, and showed excellent activity and high N 2 selectivity in a wide temperature range. NH 3 and NO oxidation was investigated to gain insight into NO reduction and N 2 O formation. The formation of N 2 O was primarily dominated by the reaction of NO with NH 3 in the presence of O 2 via the Eley-Rideal mechanism. An intimate synergistic effect existed between the Mn-based and the Ti-Zr support. It was demonstrated that the Ti-Zr support greatly promoted the catalytic performance of Mn-based catalysts., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

This paper is a comparative study of recycling rare earth elements from waste phosphor, which focuses on the leaching rate and the technical principle. The traditional and dual dissolution by hydrochloric acid (DHA) methods were compared. The method of dual dissolution by hydrochloric acid has been developed. The Red rare earth phosphor (Y0.95Eu0.05)2O3 in waste phosphor is dissolved during the first step of acid leaching, while the Green phosphor (Ce0.67Tb0.33MgAl11O19) and the Blue phosphor (Ba0.9Eu0.1MgAl10O17) mixed with caustic soda are obtained by alkali sintering. The excess caustic soda and NaAlO2 are removed by washing. The insoluble matter is leached by the hydrochloric acid, followed by solvent extraction and precipitation (the DHA method). In comparison, the total leaching rate of the rare earth elements was 94.6% by DHA, which is much higher than 42.08% achieved by the traditional method. The leaching rate of Y, Eu, Ce and Tb reached 94.6%, 99.05%, 71.45%, and 76.22%, respectively. DHA can decrease the consumption of chemicals and energy. The suggested DHA method is feasible for industrial applications., (Copyright © 2014 Elsevier B.V. All rights reserved.)

Photoelectrode made of nanocable structure of ZnO nanorods (NR) coated with TiO(2) nanosheets (NSs) was investigated for CdS/CdSe quantum dot co-sensitized solar cells. ZnO NRs prepared solution reaction at 60 °C served as the backbone for direct electron transport in view of the single crystallinity of the ZnO NRs and the high electron mobility of ZnO semiconductor. Anatase TiO(2) NSs with the thickness of ∼10 nm and the length of ∼100 nm were assembled onto the surface of ZnO NRs via a solvothermal method. It was found that the thin shell of TiO(2) might have remarkable influence on the quantum dot sensitized solar cells (QDSCs) through (a) increasing the surface area of ZnO NRs to allow for adsorbing more quantum dots (QDs), which led to high short current density, (b) forming an energy barrier that hindered the electrons in the ZnO from being back to the electrolyte and QDs, and thus, reduced the charge recombination rate, resulting in prolonged electron lifetime and enhanced open voltage. In comparison with the case of ZnO NRs, the short-circuit current density, open-circuit voltage, fill factor and charge recombination resistance of ZnO/TiO(2) nanocable photoelectrode increase by 3%, 44%, 48% and 220%, respectively. As a result, a power conversion efficiency of 2.7% of QDSCs with core-shell structural nanocable photoelectrode has been obtained, which is as much as 230% of that of 1.2% obtained for ZnO NR photoelectrode.