Novel two-dimensional β-GeSe and β-SnSe semiconductors: anisotropic high carrier mobility and excellent photocatalytic water splitting

Abstract

Photocatalytic water splitting is a promising method which uses the sunlight to directly generate hydrogen from water in meeting the requirement of energy consumption. Inspired by the experimental realization of...

Revisiting the Chemical Stability of Germanium Selenide (GeSe) and the Origin of its Photocatalytic Efficiency

“…Furthermore, also in the monolayer regime, the flexibility of free-standing membrane should be carefully considered in theoretical models, as it can significantly influence energetics of the adsorption, as recently demonstrated for the case of InSe and GaSe nanosheets. [23] Other works [16,25] considered a possible catalytic efficiency of β-GeSe (i.e., an allotrope with distorted h-BN structure). The β-GeSe allotrope can be discussed as a model of (001)-oriented surface of GeSe in ground state tetrahedral phase or grain boundaries.…”

“…Based on such a supposed oxidation resistance, correspondingly, theoretical models explain the photocatalytic activity of GeSe in terms of small exciton binding energy (0.5 eV), particularly suitable for separating photogenerated carriers (holes and electrons). [16] Here, we show that this picture should be radically revisited, due to the unambiguous detection of a sub-nanometric surface oxide skin in GeSe, which plays a key role in the physicochemical mechanisms ruling catalytic reactions. Specifically, by means of surface-science tools and density functional theory, we demonstrate the existence of surface oxide phases, whose emergence was overlooked by all previous investigations, due to the insufficient surface sensitivity of spectroscopic and microscopic tools employed so far.…”

Two-dimensional β-PdX2 (X = S, Te) monolayers for efficient solar energy conversion applications

“…At pH ¼ 7, an additional external potential of 0.13 V is needed to be employed to drive the HER to occur spontaneously (Fig. 6(d)), which is similar to b-GeSe (0.13 V) 74 and much lower than b-AuS (0.16 V), 75 b-SnSe (0.16 V), 74 RhTeCl (0.30 V), 76 b-PdSe 2 (0.31 V), 77 This journal is © The Royal Society of Chemistry 2022 C 3 S (0.33 V), 78 SiP 2 (0.83 V), PE-AgBiP 2 Se 6 (1.06 V) 72 and FE-AgBiP 2 Se 6 (1.62 V). 72 As illustrated in Fig.…”

Engineering 2D Materials for Photocatalytic Water-Splitting from a Theoretical Perspective

“…Calculations based on DFT have an advantage in forecasting the trend and influence of lattice strain on the photocatalytic performance of 2D materials in water splitting [ 87 ]. A few examples include noble metals, 2D transition-metal complexes, heterostructure, and perovskite oxides, indicating that lattice strain has a lot of potential for changing the photocatalytic performance for water splitting [ 89 , 101 , 163 , 164 , 165 , 166 , 167 , 168 , 169 , 170 , 171 , 172 , 173 , 174 , 175 , 176 , 177 , 178 ].…”