arXiv subjects

Caique C. Oliveira

Publications and source records attributed to Caique C. Oliveira.

3 recordsLinked to original sources

arXiv2026

Transforming Discarded Thermoelectrics into High-Performance HER Catalysts

With the increase in the complexity of the materials used in various sophisticated electronic devices, recycling of E-waste is becoming challenging. In the present study, we have converted thermoelectric (TE) waste into functional HER electrocatalyst by considering circular-economy and low-carbon approach. The as received TE waste was processed through ball milling (TE waste-BM) and melting casting (TE waste-M) routes. Morphological and structural evaluations revealed that the formation of BiSbTe3/ZnTe heterostructure in TE-waste-M promote HE efficiency when compared to the presence of Bi2Te3/BiSbTe3 heterostructure (TE-waste-BM). TE waste-M exhibited lower overpotential (641 mV at 10 mA/sq.cm), smaller Tafel slope (233 mV/dec) and stable operation for 5.5 h with negligible current decay than that of TE waste-BM, attributed to the accelerated charge transfer, fast water dissociation steps and rapid hydrogen adsorption in TE waste-M, originated from the presence of BiSbTe3/ZnTe heterostructure, defect enriched interfaces. Density functional theory calculations supported the experimental findings, revealing that heterostructures strengthens the bonding states near the Fermi level, thereby enhancing the HER activity of BiSbTe3/ZnTe heterostructure. This work simultaneously integrates waste management with green hydrogen production by offering an economically viable, scalable and low-carbon approach for HER catalysts.

cond-mat.mtrl-sci↗

arXiv2025

Strain Modulated Catalytic Activity of Pt2XSe3 (X = Hg, Zn) for Hydrogen Evolution Reaction

The catalytic properties of Pt2XSe3 (X = Hg, Zn) in hydrogen-electrode- (HER-) based catalysts have been investigated based on state-of-the-art ab initio simulations. Our results show that the late transition metal sites (Hg and Zn) exhibit the best activity for HER in an acidic environment. Furthermore, lattice stretching and compression can effectively modulate the H binding energy, achieving almost thermoneutral adsorption at 3% compressive strain. The changes are attributed to the modulation in the d-band centers of late transition metal sites, as well as the depletion of charge population on bonding states, contributing to the destabilization of the H-metal bonds. Our contribution explores strain engineering as an effective strategy to tailor the activity of 2D mineral-based catalyst materials for HER, advancing our understanding of how mechanical manipulation can effectively modulate the catalytic properties of these materials.

cond-mat.mtrl-sci↗

arXiv2023

Tetra-penta-deca-hexagonal-graphene (TPDH-graphene) hydrogenation patterns: dynamics and electronic structure

The advent of graphene has renewed the interest in other 2D carbon-based materials. Bhattacharya and Jana have proposed a new carbon allotrope, composed of different polygonal carbon rings containing 4, 5, 6, and 10 atoms, named Tetra-Penta-Deca-Hexagonal-graphene (TPDH-graphene). This unusual topology created material with interesting mechanical, electronic, and optical properties and several potential applications, including UV protection. Like other 2D carbon structures, chemical functionalizations can be used to tune their TPDH-graphene properties. In this work, we investigated the hydrogenation dynamics of TPDH-graphene and its effects on its electronic structure, combining DFT and fully atomistic reactive molecular dynamics simulations. Our results show that H atoms are mainly incorporated on tetragonal ring sites (up to 80% at 300 K), leading to the appearance of well-delimited pentagonal carbon stripes. The electronic structure of the hydrogenated structures shows the formation of narrow bandgaps with the presence of Dirac cone-like structures, indicative of anisotropic transport properties.

cond-mat.mtrl-sci↗