Tannic acid as an eco-friendly natural passivator for the inhibition of pyrite oxidation to prevent acid mine drainage at the source

Porous Hydrogel Photothermal Conversion Membrane to Facilitate Water Purification

“…More information about chelation was evaluated by a high-resolution Fe 2p spectroscopy (Figure b). The high-resolution Fe 2p spectrum can be deconvoluted into four Gaussian peaks at 710.28, 713.48, 723.38, and 726.88 eV, corresponding to Fe 2p 3/2 (FeII), Fe 2p 3/2 (FeIII), Fe 2p 1/2 (FeII), and Fe 2p 1/2 (FeIII). , The generation of FeII may be related to the redox balance of the catechol functional group/Fe­(III). Previous studies have confirmed that TA converts Fe 3+ into Fe 2+ under acidic conditions .…”

Investigating the oxidation mechanism of facet-dependent pyrite: implications for the environment and sulfur evolution

“…All the models were calculated under a solvation model, the distance between H 2 O molecules and FeS 2 should be kept at 7 Å to avoid their unnecessary contact. The surface energy and adsorption energy were calculated by the following equations (eqn (7) and (8)):…”

“…In eqn (7), E unrelax slab , E relax slab , E bulk , n and A represent the energy of the unrelaxed slab model, the energy of the relaxed slab model, the energy of the bulk crystal, the number of atoms in the slab model and the total area of the surface slab model, respectively. As for eqn (8), E slab+mole , E slab and E mole in this system represent the total energy of the slab model, O 2 and H 2 O molecules, the energy of the relaxed slab model, and the energy of O 2 and H 2 O molecules, respectively.…”

“…H 2 O molecules are not oxidizing agents, but they are involved in the oxidation of pyrite. 8 Oxidizing bacteria (especially acidophiles such as Thiobacillus ferrooxidans) also occupy a pivotal position in accelerating the oxidation process. [9][10][11] As a whole, the oxidation process of FeS 2 can be summarized as eqn (1)- (6).…”

A highly explicit electrochemical biosensor for catechol detection in real samples based on copper-polypyrrole

“…The greater density of active sites on the surface of the metal or metal-conducting polymer composite surface eases the reversibility of catechol oxidation/reduction at the surface. 21 These conducting polymers have excellent chemical and thermal stability, and reproducibility as electrochemical sensor materials. Incorporating metal NP particles in conducting polymers makes the flow of electrons more efficient.…”