Two-dimensional ferroelectric MoS₂/Ga₂O₃ heterogeneous bilayers with highly tunable photocatalytic and electrical properties

Abstract

Two-dimensional van der Waals heterostructures with strong intrinsic ferroelectrics are highly promising for novel devices with designed electronic properties. The polarization reversal transition of the 2D ferroelectric Ga2O3 monolayer offers...

Monolayer Fullerene Networks as Photocatalysts for Overall Water Splitting

“…The exciton absorbance peaks in monolayer qHP C 60 networks around 2 eV can maximize the solar energy absorption for water splitting. , For an overall water splitting reaction, the energy levels of the CBM and VBM must straddle the redox potentials of water. In other words, the CBM (with respect to the vacuum level) should be higher than the hydrogen evolution potential of −4.44 + pH × 0.059 eV, while the VBM should be lower than the oxygen evolution potential of −5.67 + pH × 0.059 eV. ,, To determine the band edge positions of qTP1, qTP2, and qHP C 60 monolayers, the vacuum levels of all three phases are calculated by averaging the electrostatic potential along the c axis. Figure a summarizes the HSE band alignment of all three C 60 monolayers with μ = 0.11 Å –1 (for band alignment calculated with PBEsol, HSEsol and unscreened hybrid functional, see the Supporting Information).…”

“…In addition, the band alignment in these heterostructures can be further controlled by external strain because of the mechanical flexibility of 2D materials. − Compared to heterostructures using C 60 molecules where the low C 60 content is not periodically bounded at the edge of the other 2D material, heterostructures using monolayer polymetric fullerene has a smooth microscopic surface with uniform periodic C 60 networks, which provides higher crystallinity with higher C 60 concentrations and consequently increases the photocatalytic activity. Compared to other 2D materials, − monolayer C 60 has larger surface area with more active sites due to the quasi-0D network structures of C 60 cages. Additionally, monolayer C 60 exhibits good thermodynamic stability and high carrier mobility .…”

Evidence of direct Z-scheme triazine-based g-C3N4/BiOI (001) heterostructures: a hybrid density functional investigation

“…Due to the negative binding energy, this heterostructure is thermodynamically stable, which means it can be prepared or grown in a practical way. 70,71 Indeed, the thermostability of the heterojunction g-C 3 N 4 /BiOI (001) is verified via an AIMD simulation at 300 K, shown in Fig. 4(a) and (b).…”

Size and Composition Dependent Electronic, Structural and Optical Properties of Transition Metal Dichalcogenide Nanoflakes

“…These materials are known to show excellent quantum confinement effects, which convert it from an indirect to direct band gap semiconductor when thinned down from its bulk to monolayer form [4][5][6]. These monolayers interact strongly with light and the interactions can be regulated at the atomic length scale by modifying the electronic properties via mechanical strain, electric fields, or through van der Waals heterostructures [7].…”