Spent potlining (SPL) hazardous waste is a potentially valuable source of fluoride, which may be recovered through chemical leaching and adsorption with a selective sorbent. For this purpose, the commercially available chelating resin Purolite S950+ was loaded with lanthanum ions, to create a novel ligand-exchange sorbent. The equilibrium fluoride uptake behaviour of the resin was thoroughly investigated, using NaF solution and a simulant leachate of SPL waste. The resin exhibited a large maximum defluoridation capacity of 187 ± 15 mg g from NaF solution and 126 ± 10 mg g from the leachate, with solution pH being strongly influential to uptake performance. Isotherm and spectral data indicated that both chemisorption and unexpected physisorption processes were involved in the fluoride extraction and suggested that the major uptake mechanism differed in each matrix. The resin demonstrates significant potential in the recovery of fluoride from aqueous waste-streams.

The development of scalable deposition methods for perovskite solar cell materials is critical to enable the commercialization of this nascent technology. Herein, we investigate the use and processing of nanoparticle SnO2 films as electron transport layers in perovskite solar cells and develop deposition methods for ultrasonic spray coating and slot-die coating, leading to photovoltaic device efficiencies over 19%. The effects of postprocessing treatments (thermal annealing, UV ozone, and O2 plasma) are then probed using structural and spectroscopic techniques to characterize the nature of the np-SnO2/perovskite interface. We show that a brief “hot air flow” method can be used to replace extended thermal annealing, confirming that this approach is compatible with high-throughput processing. Our results highlight the importance of interface management to minimize nonradiative losses and provide a deeper understanding of the processing requirements for large-area deposition of nanoparticle metal oxides.

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Surface-initiated activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) is used to polymerize a cis-diol-functional methacrylic monomer (herein denoted GEO5MA) from planar silicon wafers. Ellipsometry studies indicated dry brush thicknesses ranging from 40 to 120 nm. The hydrophilic PGEO5MA brush is then selectively oxidized using sodium periodate to produce an aldehyde-functional hydrophilic PAGEO5MA brush. This post-polymerization modification strategy provides access to significantly thicker brushes compared to those obtained by surface-initiated ARGET ATRP of the corresponding aldehyde-functional methacrylic monomer (AGEO5MA). The much slower brush growth achieved in the latter case is attributed to the relatively low aqueous solubility of the AGEO5MA monomer. X-ray photoelectron spectroscopy (XPS) analysis confirmed that precursor PGEO5MA brushes were essentially fully oxidized to the corresponding PAGEO5MA brushes within 30 min of exposure to a dilute aqueous solution of sodium periodate at 22 °C. PAGEO5MA brushes were then functionalized via Schiff base chemistry using an amino acid (histidine), followed by reductive amination with sodium cyanoborohydride. Subsequent XPS analysis indicated that the mean degree of histidine functionalization achieved under optimized conditions was approximately 81%. Moreover, an XPS depth profiling experiment confirmed that the histidine groups were uniformly distributed throughout the brush layer. Surface ζ potential measurements indicated a significant change in the electrophoretic behavior of the zwitterionic histidinefunctionalized brush relative to that of the non-ionic PGEO5MA precursor brush. The former brush exhibited cationic character at low pH and anionic character at high pH, with an isoelectric point being observed at around pH 7. Finally, quartz crystal microbalance studies indicated minimal adsorption of a model globular protein (BSA) on a PGEO5MA brush-coated substrate, whereas strong protein adsorption via Schiff base chemistry occurred on a PAGEO5MA brush-coated substrate.

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Graphite-like carbon was found to be formed by leaf organics and rail steels, causing low friction between wheels and rails.

Organic-inorganic metal halide perovskites are rapidly approaching state-of-the-art silicon solar cells, with bestperforming devices now reaching power conversion efficiencies (PCEs) of 25.7%. [1] Although stability remains a challenge for perovskite solar cells (PSCs), their solution-processability represents a major advantage. Techniques such as blade coating, [2] slot-die coating, [3] and spray coating [4] are compatible with roll-to-roll (R2R) processing, which-in principleshould allow much higher throughput speeds than existing silicon solar technologies. However, the lengthy annealing times used to crystallize the perovskite active layer reduce the maximum theoretical web speeds that could be achieved in a practical manufacture process.In 2020, Rolston et al. demonstrated the highest coating speeds of any scalable PSC processing technologies, achieving production speeds of >12 m min −1 . [5] Spray coating was combined with an atmospheric plasma postprocessing route, [6] creating PSC devices and modules with a PCE of 18% and 15.5%, respectively. Critically, these were fabricated without annealing the perovskite layer. At these speeds, the module cost is expected to be fully competitive with Si. [7] In contrast, the calculated throughput rate for spin-coated PSCs incorporating a 10-min anneal is just 0.017 m min −1 ; a rate prohibitive for commercialization. Furthermore, high temperature processing steps increase device manufacturing costs through increased utility costs and reduced throughput. [8] High process temperatures are also incompatible with many sensitive flexible (polymeric) substrates that are expected to be important in "Internet of Things" applications. [9,10] This growing market is expected to reduce the initial investment and barrier to market entry for perovskites by an order of magnitude. [11] Many approaches to create "annealing-free" PSCs have been demonstrated. For example, thermal evaporation of the perovskite layer without any post-annealing treatments can be used to realize devices having reasonable PCEs of up to 15.7%. [12,13] Zhou et al. demonstrated devices with a PCE of 15.7% for MAPbI 3 (where MA is methylammonium) films grown via electrochemical fabrication. [14] The use of antisolvent High temperature post-deposition annealing of hybrid lead halide perovskite thin films-typically lasting at least 10 min-dramatically limits the maximum roll-to-roll coating speed, which determines solar module manufacturing costs. While several approaches for "annealing-free" perovskite solar cells (PSCs) have been demonstrated, many are of limited feasibility for scalable fabrication. Here, this work has solvent-engineered a high vapor pressure solvent mixture of 2-methoxy ethanol and tetrahydrofuran to deposit highly crystalline perovskite thin-films at room temperature using gas-quenching to remove the volatile solvents. Using this approach, this work demonstrates p-i-n devices with an annealing-free MAPbI 3 perovskite layer achieving stabilized power conversion efficiencies (PCEs) of up to 1...