Unravelling the Impact of Porosity on Water Stability of Porous Bi(III) Halide Semiconductors and Their Potential for Red Tide Mitigation

Hybrid metal halide semiconductors are a unique family of materials with immense potential for numerous applications. For this to materialize, environmental stability and toxicity deficiencies must be simultaneously addressed. We report here a porous, visible light semiconductor, namely, (DHS)Bi2I8 (DHS = [2.2.2] cryptand), which consists of nontoxic, earth-abundant elements, and is water-stable for more than a year. Gas- and vapor-sorption studies revealed that it can selectively and reversibly adsorb H2O and D2O at room temperature (RT) while remaining impervious to N2 and CO2. Solid-state NMR measurements and density functional theory (DFT) calculations verified the incorporation of H2O and D2O in the molecular cages, validating the porous nature. In addition to porosity, the material exhibits broad band-edge light emission centered at 600 nm with a full width at half-maximum (fwhm) of 99 nm, which is maintained after 6 months of immersion in H2O. Moreover, (DHS)Bi2I8 exhibits bacteriocidal action against three Gram-positive and three Gram-negative bacteria, including antibiotic-resistant strains. This performance, coupled with the recorded water stability and porous nature, renders it suitable for a plethora of applications, from solid-state batteries to water purification and disinfection.

Phosphonium-based (R-P(R')3+) metal halide semiconductors (MHS) emerged recently as a promising family of materials offering enhanced water and thermal stability over conventional ammonium-based (R-NH3+) MHS. Despite this performance, there is a lack of systematic studies that elucidate the origin of these features as well as the underlying optoelectronic properties. We report here the synthesis of nine new 1D materials (L)PbX3 (L = C4-P, C6-P, C6-N, P3-P, P4-P, X = I, Br), using custom-made organic ligands, namely, butyl(triethyl)phosphonium bromide (C4-P), hexyl(triethyl)phosphonium bromide (C6-P), benzyl(triethyl)phosphonium bromide (P3-P), benzyl(trimethyl)phosphonium bromide (P4-P), and hexyl(triethyl)ammonium bromide (C6-N). Some of the materials have been water-stable for 2 years so far, while the assembly of the isostructural (C6-N)PbBr3 and (C6-P)PbBr3 allowed us to directly identify the impact of a single atom (phosphorus versus nitrogen) on water stability. Notably, the C6-P analog remains water-stable for 2 years, whereas the C6-N analog dissolves in water. It was found that neither crystal packing nor the lack of hydrogen bond interactions with water is responsible for this record stability performance, challenging currently established claims on the origin of water stability in MHS. All materials feature broad light emission at RT, with (P3-P)PbBr3 exhibiting a PLQY of 22.0% ascribed to permanent traps, while electrochemical studies uncovered for the first time the redox properties and their strong potential for the sensing of per- and polyfluoroalkyl substances (PFAS) in water samples. Our work showcases the potential of these compounds for applications where thermal and water stabilities are interwoven, potentially rendering their (R-NH3+)-based counterparts obsolete.

短裸甲藻毒素(BTX-A)是由有害藻类短裸甲藻产生的次生代谢物,检测海水中的藻毒素可以预测赤潮的发生和增长。将BTX-A含量监测作为赤潮预警的因子之一可以有效提高赤潮预警的准确性,开发一种高效富集海水中BTX-A的样品前处理方法迫在眉睫。研究通过溶剂热法制备了具有较大比表面积(310.9 m2/g)、对BTX-A有较强吸附作用的微米级Zr-MOFs复合材料(SiO2@UiO-66),并将其作为固相萃取(SPE)填料,结合高效液相色谱-串联质谱(HPLC-MS/MS)技术,建立了一种检出限低(3.0 pg/mL)、线性范围宽(10.0~200.0 pg/mL)、重复性良好(RSD≤8.5%, n=6)的海水中BTX-A的高灵敏检测方法。所建立的分析方法成功用于实际海水样品中BTX-A含量的分析和监测,结合福建省海洋与渔业局所发布的赤潮监测预警信息,可作为赤潮预警因子有效提高赤潮的监测和预警。

Jinhae Bay, a semi-enclosed bay on the southern coast of Korea, is a major aquaculture area that forms a spawning ground and nursery for commercially important fishes. Since the late 1960s, industrial and domestic waste from adjacent cities and industrial complexes has been released into the region, resulting in chronic hypoxia and red tides. As a central site of environmental monitoring efforts for aquaculture and fisheries in southeastern Korea, Jinhae Bay was surveyed every 2 months usually, and every 2–3 weeks during the hypoxia season, with the seawater properties observed at approximately 31–34 stations. The maximum area and duration of hypoxia in Jinhae Bay occurred in 2016 (316 km2 and 26 weeks, respectively), with minima of area in 2013 (213 km2) and duration in 2011 (15 weeks). Correlation analyses of the seawater properties, weather parameters, and hypoxia indices showed that the hypoxic area was positively correlated with the surface-water temperature, air temperature, and rainfall; the minimum dissolved oxygen concentrations were negatively correlated with the air and water temperatures and bottom-water nutrient levels; and the water stability was negatively correlated with the surface-water salinity and positively correlated with both the surface- and bottom-water nitrate and silicate concentrations. These findings imply that the air temperature and precipitation may be important factors in the development and persistence of hypoxia in Jinhae Bay via the control of the stratification intensity and eutrophication of the water column. Therefore, we tested these parameters for their potential to predict hypoxia. Based on our results, we propose the following trends of hypoxia in Jinhae Bay: the initial hypoxia development generally depends on the criteria of an air temperature ≥ 19.5 °C for 1 week and total precipitation > 100 mm over 4 weeks, and it becomes more severe (≥50% coverage) under strong eutrophication, mainly due to organic matter discharge following heavy rainfall, based on the logarithmic correlation with the 4-week rainfall (R2 = 0.6). Therefore, the hypoxic area index can be predicted using its linear regression relationships with the 1-week air temperature and 4-week precipitation (R2 = 0.56). This study tested the prediction of the hypoxic area based on a simple calculation method and weather parameter criteria, and it demonstrated the potential of this method for precisely forecasting hypoxia in combination with biogeochemical models or other mathematical solutions to prevent massive fishery damage.

Records of massive fish kills and paralytic shellfish poisoning (PSP) in Europe and North America go back to the 17th century. But, it was not until the 1940s when the relationship between PSP, red tide and toxic dinoflagellateGonyaulax was established. Recent records show that PSP and related poisons caused by toxic dinoflagellates in coastal waters and estuaries, are a world-wide problem. Diarrhetic shellfish poisoning (DSP) and neurotoxic poisoning (NSP), believed earlier as bacterial or viral infections are now shown to be caused by other toxic dinoflagellates such asDinophysis. The shellfish most often involved in the poisoning are mussels and clams. Other dinoflagellates,Gyrodinium, occasionally cause massive fish kills in vast coastal areas, resulting in fishery and economic losses. Factors promoting toxic dinoflagellate bloom development and PSP/DSP outbreaks are not fully understood. In previous studies, temperature was considered as the principal factor influencing dinoflagellate blooming. Recent studies showed that other factors such as salinity, sunlight, freshwater runoff and water stability are also important. Pollution from land drainage and sewage discharge in inshore waters were also implicated. Current knowledge indicates that although chemical and biotic factors are important forin-situ growth of dinoflagellate cells, convergence by thermal and tidal fronts is essential for cell accumulation and bloom development. Advances in physical oceanographic research, modelling and remote sensing enabled the detection of fronts and bordering eddies with high precision. There is a potential for an increased use of these technological advances in predicting and monitoring the bloom development. The present paper overviews the history and distribution of toxic dinoflagellates, and the physical factors influencing bloom development and PSP/DSP outbreaks. Future research needs to improve the predictability and control of this world-wide hazard are also discussed.

This invited Team Profile was created by the Spanopoulos group, University of South Florida, Tampa (USA), the Guo group, Yale University, West Haven (USA), the Trikalitis group, University of Crete, Heraklion (Greece), the Zimbouche group, Lancaster University, Lancaster (UK), and the Reddy group, University of Lille, Lille (France). They recently published an article on the development of a new family of hybrid semiconductors, namely porous metal halide semiconductors (PMHS). The first member of this series was characterized by using a battery of techniques, shedding light on the corresponding structure-property relationships and its unparalleled water stability. This work provides a solution to address the stability deficiency of metal halide semiconductors and render them suitable for yet unexplored applications, such as solid-state batteries, photonic crystals, sensing and environmental remediation: "Porous and Water Stable 2D Hybrid Metal Halide with Broad Light Emission and Selective H2 O Vapor Sorption", A. Azmy, S. Li, G. K. Angeli, C. Welton, P. Raval, M. Li, N. Zibouche, L. Wojtas, G. N. M. Reddy, P. Guo, P. N. Trikalitis, I. Spanopoulos, Angew. Chem. Int. Ed. Engl. 2023, 62, e202218429.

In this work we report a strategy for generating porosity in hybrid metal halide materials using molecular cages that serve as both structure-directing agents and counter-cations. Reaction of the [2.2.2] cryptand (DHS) linker with PbII in acidic media gave rise to the first porous and water-stable 2D metal halide semiconductor (DHS)2 Pb5 Br14 . The corresponding material is stable in water for a year, while gas and vapor-sorption studies revealed that it can selectively and reversibly adsorb H2 O and D2 O at room temperature (RT). Solid-state NMR measurements and DFT calculations verified the incorporation of H2 O and D2 O in the organic linker cavities and shed light on their molecular configuration. In addition to porosity, the material exhibits broad light emission centered at 617 nm with a full width at half-maximum (FWHM) of 284 nm (0.96 eV). The recorded water stability is unparalleled for hybrid metal halide and perovskite materials, while the generation of porosity opens new pathways towards unexplored applications (e.g. solid-state batteries) for this class of hybrid semiconductors.

This invited Team Profile was created by the Spanopoulos group, University of South Florida, Tampa (USA), the Guo group, Yale University, West Haven (USA), the Trikalitis group, University of Crete, Heraklion (Greece), the Zimbouche group, Lancaster University, Lancaster (UK), and the Reddy group, University of Lille, Lille (France). They recently published an article on the development of a new family of hybrid semiconductors, namely porous metal halide semiconductors (PMHS). The first member of this series was characterized by using a battery of techniques, shedding light on the corresponding structure–property relationships and its unparalleled water stability. This work provides a solution to address the stability deficiency of metal halide semiconductors and render them suitable for yet unexplored applications, such as solid‐state batteries, photonic crystals, sensing and environmental remediation: “Porous and Water Stable 2D Hybrid Metal Halide with Broad Light Emission and Selective H2O Vapor Sorption”, A. Azmy, S. Li, G. K. Angeli, C. Welton, P. Raval, M. Li, N. Zibouche, L. Wojtas, G. N. M. Reddy, P. Guo, P. N. Trikalitis, I. Spanopoulos, Angew. Chem. Int. Ed. Engl. 2023, 62, e202218429.

In this work we report a strategy for generating porosity in hybrid metal halide materials using molecular cages that serve as both structure‐directing agents and counter‐cations. Reaction of the [2.2.2] cryptand (DHS) linker with PbII in acidic media gave rise to the first porous and water‐stable 2D metal halide semiconductor (DHS)2Pb5Br14. The corresponding material is stable in water for a year, while gas and vapor‐sorption studies revealed that it can selectively and reversibly adsorb H2O and D2O at room temperature (RT). Solid‐state NMR measurements and DFT calculations verified the incorporation of H2O and D2O in the organic linker cavities and shed light on their molecular configuration. In addition to porosity, the material exhibits broad light emission centered at 617 nm with a full width at half‐maximum (FWHM) of 284 nm (0.96 eV). The recorded water stability is unparalleled for hybrid metal halide and perovskite materials, while the generation of porosity opens new pathways towards unexplored applications (e.g. solid‐state batteries) for this class of hybrid semiconductors.

Hybrid halide perovskite semiconductors have proven to be prominent candidates for many optoelectronics applications, spanning from solar cells and LEDs to photodetection and lasing. They exhibit a unique combination of fine-tunable traits that cannot be met by any other class of semiconductors, deriving directly from their hybrid nature. Finding a way to generate porosity in this class of materials would allow them to be utilized in currently unexplored applications such as sensing, photonic crystals, integrated waveguides, and solid-state batteries (SSB).We recently developed a general strategy for generating porosity to hybrid metal halide materials using molecular cages serving as structure-directing agents and counter-cations. [1][2] The reaction of the [2.2.2] cryptand (DHS) linker with Pb(II) in acidic media gave rise to the first porous 2D metal halide semiconductor with formula (DHS)2Pb5Br14. The corresponding material is stable in water for over a year, while gas and vapor sorption studies revealed that it can selectively and reversibly adsorb H2O and D2O at room temperature (RT). Solid-state NMR measurements and DFT calculations verified the incorporation of H2O and D2O in the organic linker cavities, and shed light on their molecular configuration. In addition to porosity, the material exhibits broad light emission centered at 617 nm with a full width at half-maximum (FWHM) of 284 nm (0.96 eV). The recorded water stability is unparalleled for hybrid metal halide and perovskite materials, while the generation of porosity opens up new pathways toward unexplored applications (e.g. SSB) for this class of hybrid semiconductors. Porous MHS loaded with alkali metal cations would offer advantages in SSB design, such as reduced local current density, uniform and better ion flux promotion, dendrite growth suppression, reduced mechanical stress (during charge and discharge), and improved charge density. This work sets the foundation for a new family of versatile hybrid semiconductors, namely porous metal halide semiconductors (PMHS), solving current stability material deficiencies, whereby means of molecular and crystal engineering, the path towards commercialization is open.

Population dynamics of Noctiluca scintillans during a bloom in a semi-enclosed bay in Hong Kong