Metal-Embedded Graphene as Potential Counter Electrode for Dye-Sensitized Solar Cell

Abstract

It is very important to explore a cheap but efficient catalyst as a counter electrode in a dye-sensitized solar cell (DSSC). In the present work, density functional theory (DFT) calculations were performed to investigate the reduction of triiodide ion catalyzed by a metal atom embedded in graphene. It is shown that the binding energy of a single Pt atom embedded into the divacancy of graphene (Pt@DV) is about −11.0 eV, larger than the location of Pt at single vacancy (Pt@SV). In the Pt@DV with a Pt loading of 25 wt %, the adsorption energy of the iodine atom and the dissociation energy of the iodine anion are respectively −1.54 and 0.60 eV, indicating a potential high catalytic activity of Pt–graphene. Further investigations of diverse transition-metal-embedded graphenes ranging from Sc to Zn imply that the Co-embedded graphene (in divacancy) may be a good candidate to be utilized as counter electrode in DSSC.

Graphene-Based Nanomaterials for Catalysis

“…DFT can describe and predict the chemical and physical properties of pure and functionalized materials by investigating the electronic structure. − With DFT computations, many graphene-based nanomaterials have been explored and designed, and fantastic properties are disclosed. Two main classes of standard DFT, plane-wave DFT (such as VASP, SIESTA, CASTEP, ABINIT, and Quantum ESPRESSO) and local orbitals DFT (such as Gaussian, ADF, and TURBOMOLE), have been implemented for graphene-based catalysis. The results derived from DFT over graphene-based catalysts have been widely adopted for determining the rate-limiting step and active sites, investigating adsorption and activation mechanisms, activation energy calculations, and catalytic pathway discussions, which cover almost all catalysis related topics.…”

“…It has shown many attractive properties, such as quantum hall effect (QHE), large theoretical specific surface area (2630 m 2 g –1 ), high intrinsic electron mobility (∼200 000 cm 2 V –1 s –1 ), high Young’s modulus (∼1 TPa), good optical transparency (∼97.7%) and excellent thermal conductivity (3000–5000 W m –1 K –1 ) . The unique nanostructure and properties make it very promising for potential applications over a wide range of areas, such as separation, , environment, − memory devices, , transistors, transparent conducting electrodes, , optical modulator, surface-enhanced Raman spectroscopy, − sensor, , dye-sensitized solar cell (DSSC), − supercapacitor, , batteries, − fuel cell, , catalysis, , and even medicine. − …”

Experimental and Theoretical Exploration of In Situ Grown Fe3S4/Co3S4 Heterostructure as Efficient Catalyst for I3 − Reduction Reaction

“…Normally, the first nonelectrochemical step of I 3 − dissociation into I 2 and I − occurs rapidly at the CE/electrolyte interface. 46 As such, the latter two steps are often treated as the rate-determining step. 47 The adsorption behavior of I atom on various surfaces should be clarified since the associated adsorption energies are previously considered to be a typical descriptor for the IRR activity.…”

Bilayer CdS Structure: A Promising Candidate for Photocatalytic and Optoelectronic Applications

“…2D-materials have gained significant attention during the present decade because of their novel electronic, optical, and mechanical properties compared to those of their corresponding bulk counterparts. These 2D materials are widely used in several technological applications including nanoelectronics, ,,, optoelectronics, , spintronics, , thermoelectric devices, energy storage, , hydrogen storage devices, electrodes in batteries, gas sensing, − solar cells, catalysts, etc. because of their large surface area, high mechanical and chemical stability, and enriched electrical conductivity .…”