Janus Ga₂SSe nanotubes as efficient photocatalyst for overall water splitting

Abstract

The use of sunlight to split water into hydrogen and oxygen is one of the important means to solve the current world energy and environmental problems. In this paper, we use density functional theory to predict the photocatalytic performance of Janus Ga2SSe nanotubes (JGSSe NTs) for the first time. The results show that the small formation energy and strain energy ensure that the nanotubes are stable. The JGSSe NTs also exhibit a wider range of visible light absorption than monolayers, and large radius (>26.60 Å) nanotubes all meet the hydrolysis potential. Surprisingly, the JGSSe NT exhibit an estimated hole mobility of up to 2.89×104 cm2 V-1 S-1.All in all, the JGSSe nanotube exhibit low electron-hole recombination rate, high hole mobility, solar absorption in the visible light range and excellent oxidation ability, which is expected to become an outstanding photocatalyst. In addition, the nanotube band gap can be effectively regulated by applying strain. It is hoped that our research will provide meaningful advances in the development of novel and efficient photocatalysts. We hope that our research will provide a possible way to develop novel and efficient photocatalysts.

Dual Polarization Strategy for Boosting Electron–Hole Separation toward Overall Water Splitting within Ferroelectric β-AIBIIIO2 (BIII = P3+, As3+, Sb3+, and Bi3+ for Lone Pairs)

“…Based on the theory of deformation potential, which has been adopted in photocatalysis, − we applied uniaxial stress to the bulk polarization direction of β-A I B III O 2 and calculated the carrier migration rates in the [001] direction of four candidates using the following equation: μ = 8 π e ℏ 4 c i i 3 false( m * ) 5 / 2 false( k 0 T ) 3 / 2 E 1 2 where c ii represents the elastic constant, taking c 33 for the z -direction, m * is the effective mass (Table S7), E 1 corresponds to the deformation potential, and k 0 is the Boltzmann constant . The calculation results in Table show that the electron mobility of the four screened four candidates ranges from 10 5 to 10 6 cm 2 s –1 V –1 , which is much higher than that of H-TiO 2 (23.63 cm 2 s –1 V –1 ), ZnO (430.72 cm 2 s –1 V –1 ), Ga 2 SSe nanotubes (500 cm 2 s –1 V –1 ), and even NaIrO 2 (3138.23 cm 2 s –1 V –1 ) . The hole mobility of β-LiBiO 2 and β-TlBiO 2 reaches as high as 10 4 cm 2 s –1 V –1 , and even β-NaSbO 2 with the lowest hole mobility (838.1 cm 2 s –1 V –1 ) is higher than that of the high-mobility semiconductor Si (505 cm 2 s –1 V –1 ), highlighting that these four candidates exhibit excellent photocatalytic migration of photogenerated carriers.…”

First principles calculations of the electronic configuration and photocatalytic performance of GaSe(Ga2SSe)/MoS2(MoSSe) heterojunctions

“…In 2017, Lu et al prepared monolayers of Janus MoSSe by chemical vapor deposition and further confirmed the existence of Janus MoSSe via scanning electron microscopy and X-ray photoelectron spectroscopy. 11 At present, the polar materials that have been reported are MXY (M = Mo, W, Cr, Pt; X, Y = O, S, Se, Te; XaY), [12][13][14][15] M 2 X 3 (M = Al, Ga, In; X = S, Se, Te), [16][17][18][19] Ga 2 XY(Y = S, Se, Te; X = S, Se, Te), [20][21][22][23][24][25] etc. The destruction of structural symmetry has a crucial role in the electronic structure of 2D materials as a result of the induced dipole arising along the vertical direction of 2D materials.…”

“…29 On the other hand, Ga 2 XY (Y = S, Se, Te; X = S, Se, Te) is achieved by completely replacing one of the layers of Se atoms with S atoms on the basis of MX materials, while the other atoms remain invariant. [30][31][32] Experimentally, 2D Ga 2 SSe can be synthesized by chemical vapor deposition and mechanical exfoliation techniques. 33 Bui et al discovered the promising application of Ga 2 XY monolayers in UV detectors, 34 and Jappo et al reported the effect of biaxial strain on Ga 2 SSe monolayers, and it was found that the optical and electronic performance of monolayer Ga 2 SSe materials varied with the applied strain.…”

“…[30][31][32] Experimentally, 2D Ga 2 SSe can be synthesized by chemical vapor deposition and mechanical exfoliation techniques. 33 Bui et al discovered the promising application of Ga 2 XY monolayers in UV detectors, 34 and Jappo et al reported the effect of biaxial strain on Ga 2 SSe monolayers, and it was found that the optical and electronic performance of monolayer Ga 2 SSe materials varied with the applied strain. 35 Furthermore, in 2020, Vu et al reported the behavior of a series of Janus single molecular layers of Ga 2 SeTe, Ga 2 STe, SnSSe, and Al 2 SSe.…”