Influence of Environmentally Relevant Physicochemical Conditions on a Highly Efficient Inorganic Ice Nucleating Particle

Abstract

Ice nucleation microphysical processes are identified to be of high importance in forecasting the magnitude of the Earth’s climate change. The environmental conditions often influence the ice nucleation processes in the Earth’s atmosphere. We herein study the impact of various environmental conditions on FeHg (maghemite–Hg2Cl2 composite), a highly efficient ice nucleating particle with similar freezing point to the best inorganic ice nuclei, AgI. FeHg is formed from FeCl2·4H2O and HgCl2, which are observed in the environment, in contrast to AgI, which is rarely found. The ice nucleation efficacy remained unchanged for FeHg under ambient conditions for a long duration. To mimic the atmosphere, we performed a series of experiments using a suite of complementary techniques, at various levels of radiation intensity, temperature, and pH for FeHg. Experiments were also performed in the presence of atmospheric pollutants, such as ozone (in the presence or absence of light), as well as nine emerging metal oxides and NO2. The emerging metal oxides at various pH levels produced significant effects on the ice nucleation ability of FeHg. Elevated temperatures changed the maghemite of FeHg to β-Fe2O3, whereas other studied environmentally relevant physicochemical conditions could not alter the maghemite phase. We describe potential reaction mechanisms using our observations. To evaluate the effect of surface alterations, the passivation of clay materials, namely, kaolin and montmorillonite, was also performed on FeHg. The observed alteration in crystal structure, as found in X-ray diffraction, was attributed to the change of the extent of lattice mismatch, resulting in a significant variation of ice nucleation ability. Our insights of the ice nucleating particles may help understand real atmospheric ice nucleation processes, in association with the establishment of more in-depth understanding of ice nucleation mechanism in the Earth’s atmosphere.

Ice Nucleation of Model Nanoplastics and Microplastics: A Novel Synthetic Protocol and the Influence of Particle Capping at Diverse Atmospheric Environments

“…There are rarely any reports so far for heterogeneous ice nucleation in the immersion mode of ZnO. We reported previously that ZnO reduced INE of purely inorganic and environmentally available ice nucleating particles. In this study, we found that plastic nano- and microparticles decreased the INE of ZnO.…”

“…Electron microscopy imaging did not indicate the roughness of the plastic particles. Therefore, it is likely that a mechanism related to the low lattice mismatch between ice and plastic particles is attributed to enhancement of INE. , …”

“…Therefore, it is likely that a mechanism related to the low lattice mismatch between ice and plastic particles is attributed to enhancement of INE. (58,61) The difference of the INE of plastic particles with several contaminants was likely the outcome of the above factors. We herein investigated three types of plastic particles at various conditions to understand the tentative effect of the nano-and microplastics in the atmosphere in the context of INE.…”

Natural Kaolin: Sustainable Technology for the Instantaneous and Energy‐Neutral Recycling of Anthropogenic Mercury Emissions

“…Kaolin contaminated with CuCl 2 was a highly efficient adsorbent, able to take up gaseous elemental Hg within seconds at room temperature (16.33 mg g −1 of Cu from inductively coupled plasma mass spectrometry analysis). Previously, we synthesized Fe composite BHFe from the reduction of FeCl 2 by NaBH 4 followed by aerial oxidation. BHFe is an efficient Hg II adsorbent and produced a highly efficient ice‐nucleating particle HgBHFe (maghemite@Hg 2 Cl 2 ) after the uptake of HgCl 2 .…”

“…Microphysics of ice nucleation to obtain furtherinsightso n potential reaction mechanism(s) Kaolin contaminated with CuCl 2 was ah ighly efficient adsorbent, able to take up gaseous elemental Hg within seconds at room temperature (16.33 mg g À1 of Cu from inductively coupled plasma mass spectrometry analysis). Previously, [27,28] we synthesized Fe composite BHFe from the reductiono fF eCl 2 by NaBH 4 followed by aerial oxidation. BHFe is an efficient Hg II adsorbenta nd produced ah ighly efficient ice-nucleating particle HgBHFe (maghemite@Hg 2 Cl 2 )a fter the uptake of HgCl 2 .I th as www.chemsuschem.org thus been shown that ionic Hg (in associationw ith Cl À )e nhanced the ice nucleation efficiency of BHFe significantly.…”