The long-term impact of coronavirus disease 2019 on environmental health: a review study of the bi-directional effect.

Background: When health systems worldwide grapple with the coronavirus disease 2019 (COVID-19) pandemic, its effect on the global environment is also a significant consideration factor. It is a two-way process where the pre-COVID climate factors influenced the landscape in which the disease proliferates globally and the consequences of the pandemic on our surroundings. The environmental health disparities will also have a long-lasting effect on public health response. Main body: The ongoing research on the novel coronavirus severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and COVID-19 must also include the role of environmental factors in the process of infection and the differential severity of the disease. Studies have shown that the virus has created positive and negative ramifications on the world environment, especially in countries most critically affected by the pandemic. Contingency measures to slow down the virus, such as self-distancing and lockdowns have shown improvements in air, water, and noise quality with a concomitant decrease in greenhouse gas emissions. On the other hand, biohazard waste management is a cause for concern that can result in negative effects on planetary health. At the peak of the infection, most attention has been diverted to the medical aspects of the pandemic. Gradually, policymakers must shift their focus to social and economic avenues, environmental development, and sustainability. Conclusion: The COVID-19 pandemic has profoundly impacted the environment, both directly and indirectly. On the one hand, the sudden halt in economic and industrial activities led to a decrease in air and water pollution, as well as a reduction in greenhouse gas emissions. On the other hand, the increased use of single-use plastics and a surge in e-commerce activities have had negative effects on the environment. As we move forward, we must consider the pandemic's long-term impacts on the environment and work toward a more sustainable future that balances economic growth and environmental protection. The study shall update the readers on the various facets of the interaction between this pandemic and environmental health with model development for long-term sustainability.

A tetra Co(II/III) complex with an open cubane Co4O4 core and square-pyramidal Co(II) and octahedral Co(III) centres: bifunctional electrocatalytic activity towards water splitting at neutral pH.

The reaction of 2,6-diformyl-4-methylphenol, 4-methoxybenzoylhydrazine and Co(OAc)2·4H2O in 1 : 2 : 2 mole ratio in methanol under aerobic conditions produced in 61% yield a tetranuclear complex having the molecular formula [CoIICoIII(µ-OAc)(µ3-OH)(µ-L)]2 where OAc- and L3- represent acetate and N',N''-(5-methyl-2-oxido-1,3-phenylene)bis(methan-1-yl-1-ylidene)bis(4-methoxybenzoylhydrazonate), respectively. The elemental analysis and the mass spectrometric data confirmed the molecular formula of the complex. It is electrically non-conducting and paramagnetic. The complex crystallized as acetonitrile solvate. The X-ray structure shows that each Co(II) centre has a distorted square-pyramidal NO4 coordination sphere, while each Co(III) centre is in a distorted octahedral NO5 environment. The four metal atoms and the four bridging O-atoms form an open cubane type Co4O4 motif. In the crystal lattice, self-assembly of the solvated complex via intermolecular O-H⋯O interaction leads to a two-dimensional network structure. The infrared and electronic spectroscopic features of the complex are consistent with its molecular structure. Cryomagnetic measurements together with theoretical calculations suggest the presence of easy-axis anisotropy for the square-pyramidal Co(II) centres. The complex is redox-active and displays metal centred oxidation and reduction responses on the anodic and cathodic sides, respectively, of the Ag/AgCl electrode. Bifunctional heterogeneous electrocatalytic activity of the complex towards O2 and H2 evolution reactions (OER and HER) in neutral aqueous medium has been explored in detail.

A Diuranyl(VI) Complex and Its Application in Electrocatalytic and Photocatalytic Hydrogen Evolution from Neutral Aqueous Medium.

The reaction of equimolar amounts of UO2(OAc)2·2H2O, 2,6-diformyl-4-methylphenol, and N-(hydroxyethyl)ethylenediamine in methanol affords a dinuclear trans-uranyl(VI) complex of the molecular formula [(UO2)2(µ-L)2] (L2- = 2-formyl-4-methyl-6-((2-(2-oxidoethylamino)ethylimino)methyl)phenolate) in 65% yield. Detailed structural elucidation of the complex was performed by using single-crystal X-ray crystallographic and spectroscopic studies. In [(UO2)2(µ-L)2], the metal centers are in edge-shared pentagonal-bipyramidal N2O5 coordination spheres assembled by the two meridional ONNO-donor bridging L2- and two pairs of mutually trans oriented oxo groups. The complex is redox active and displays two successive metal-centered one-electron reductions at Epc = -0.71 and -1.03 V in N,N-dimethylformamide solution. The redox-active complex was used as a heterogeneous catalyst for electrochemical hydrogen evolution from aqueous medium at pH 7 with a turnover frequency (TOF) of 384 h-1 and a Tafel slope of 274 mV dec-1. The Faradaic efficiency of [(UO2)2(µ-L)2] was found to be 84%. Beyond the electrocatalytic response, the [(UO2)2(µ-L)2]-TiO2-N719 composite also exhibited significant heterogeneous photocatalytic hydrogen evolution activity in neutral aqueous medium under visible light and provided a yield of 3439 µmol gcat-1 of H2 in 4 h with a TOF of 172 h-1 and apparent quantum yield (AQY) of 7.6%.