Anisotropic and High-Mobility C₃S Monolayer as a Photocatalyst for Water Splitting

Abstract

Taking into account the high conductivity and stability of carbon materials, such as graphene, and the strong polar covalent bonding character of main-group compounds, we explore potential 2D materials in the C–S binary system through first-principles structure search calculations. Herein, a hitherto unknown semiconducting C3S monolayer is identified, consisting of well-known n-biphenyl and S atom linked benzenes, exhibiting an obvious direction-dependent atomic arrangement. Thus, it exhibits anisotropic mechanical properties and carrier mobility. Its electron mobility reaches 2.14 × 104 cm2 V–1 s–1 in the b direction, along which n-biphenyl units are arranged, and is much higher than that in the well-used MoS2 monolayer and black phosphorus. Meanwhile, the C3S monolayer has high optical absorption coefficients (105 cm–1), high thermal and dynamical stabilities, and a moderate ability to split water. All these desirable properties make the C3S monolayer a promising candidate for applications in novel optoelectronic devices.

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.…”

Wide Band Gap P3S Monolayer with Anisotropic and Ultrahigh Carrier Mobility

“…On the other hand, for 2D covalent compounds, increasing the polarity of the covalent bond generally results in an enhancement of the band gap, which can be achieved by increasing the electronegativity differences between the constituent atoms, such as in CN 2 and PC 6 N . It is well-known that sulfur (S) shows a larger electronegativity than P. S atoms also have the ability to form 2D materials with other nonmetallic elements (e.g., B, C, N, and Si), − exhibiting a high structural stability and interesting properties. Moreover, S-doped black phosphorus (BP) has an improved oxygen resistance with respect to BP …”

Photocatalytic properties of anisotropic β-PtX2 (X = S, Se) and Janus β-PtSSe monolayers

“…It can be noted that the recently reported 2D photocatalyst materials with required external potential for the OER process are b-GeSe (0.49 V), 6 C 3 N 5 (0.69 V), 10 BeN 2 (0.83 V), 7 g-CN (0.93 V), 11 Pd 3 P 2 S 8 (1.07 V), 12 GaAs (1.39 V), 8 g-C 3 N 4 (1.45 V), 91 CuCl (1.61 V), 13 Janus Pd 4 S 3 Se 3 (1.76 V), 27 and C 3 S (2.03 V). 9 3.6 Solar-to-hydrogen efficiency Further, we calculated the solar-to-hydrogen efficiency, which is the product of light absorption and carrier utilization efficiency assuming 100% efficiency of the catalytic reaction: 16…”

“…To achieve highly efficient photocatalytic water splitting together with significantly reducing environmental and energy concerns, great efforts have been made to explore novel two-dimensional (2D) materials capable of harvesting sunlight with a high solar-to-hydrogen energy conversion efficiency and ability for the separation and migration of photoexcited carriers. 1,2 A variety of novel 2D materials as photocatalysts have been proposed, including PdSe 2 , 3 PdSeO 3 , 4 SiP 2 , 5 β-GeSe, 6 β-SnSe, 6 BeN 2 , 7 GaAs, 8 C 3 S, 9 C 3 N 5 , 10 g-CN, 11 Pd 3 P 2 S 8 , 12 CuCl (1.61 V), 13 AgBiP 2 Se 6 , 14 Ga 2 SSe, 15 Ga 2 S 3 , 16 HfX 3 (X = S, Se), 17 Janus MXY (M = Mo, W; XY = S, Se, Te), 18–20 Janus CrXY (XY = S, Se, Te), 21,22 Janus PdXY(XY = S, Se, Te), 23 Janus M 2 XY (M = Ga, In; XY = S, Se, Te), 24,25 Janus PdPSeX (X = O, S, Te), 26 Janus Pd 4 S 3 Se 3 , 27 and 2D honeycomb polymers. 28,29 However, due to their low energy conversion efficiency and high kinetic overpotential, only a few such 2D materials show good photocatalytic properties for water splitting.…”