Rational design of a direct Z-scheme β-AsP/SiC van der Waals heterostructure as an efficient photocatalyst for overall water splitting under wide solar spectrum

Abstract

The solution to the issue of energy scarcity lies in the search for an effective photocatalyst. In this study, the monolayers β-AsP and SiC are selected to build the heterostructure...

PtS2/GeC van der Waals heterostructure: a promising direct Z-scheme photocatalyst with high solar-to-hydrogen energy conversion efficiency for overall water splitting under acidic, alkaline, and neutral conditions and in large-strain regions

“…The negative value indicates that the HER on the GeC side of the PtS 2 /GeC heterostructure is an exothermic process and thus can be carried out spontaneously. This value is also much smaller than those of the other heterostructures such as PtS 2 /g-C 3 N 4 (1.10 eV), 8 GeC/arsenene (0.058 eV), 9 β-AsP/SiC (0.281 eV), 10 β-GeSe/HfS 2 (0.80 eV), 13 and C 2 N/SiH (1.49 eV). 47 In addition, the calculated Δ G H value for HERs on the free GeC monolayer is 0.20 eV, which is larger than a Δ G H value of −0.13 eV of the PtS 2 /GeC heterostructure.…”

“…With the aim of more accurately assessing the photocatalytic performance of the PtS 2 /GeC heterostructure, we also calculated the STH efficiency η STH of the heterostructure using the following equation: 48 η STH = η abs × η cu (10) where η abs is the solar energy harvesting capacity and η cu is the efficiency with which carrier energy is used. The η abs is defined as follows: 11) in which P(ℏω) denotes the amount of solar energy received by the area ℏω under this specific photon energy and E g is the PtS 2 /GeC heterojunction's band gap.…”

“…The traditional 2D vdW heterostructure may separate electrons and holes via charge transfer; however, this migration technique frequently lacks the greatest redox ability and cannot provide enough electrochemical power for the photocatalytic hydrolysis reaction, 5 while the photogenerated carriers with the highest oxidation and reduction potential can accumulate on various materials and take part in photocatalytic processes owing to the Z-scheme heterostructure that resembles natural photosynthesis. In contrast to the conventional type-II photocatalyst, the Z-scheme photocatalyst has significant advantages, with regard to the new characteristics of the 2D heterostructure, 6,7 and a large number of heterojunctions such as PtS 2 /g-C 3 N 4 , 8 GeC/arsenene, 9 β-AsP/SiC, 10 TiO 2 /CdS, 11 arsenene/HfS 2 , 12 β-GeSe/HfS 2 , 13 and GeC/GaN 14 have been theoretically proposed in recent years. According to the study of Fu et al , 15 MoSe/Ti 2 CO 2 heterojunctions have the ability to prevent photo corrosion and have an efficiency of up to 12% when employed for photocatalytic water hydrogen resolution.…”

First-principles prediction of a direct Z-scheme WSe2/HfS2 van der Waals heterostructure for overall photocatalytic water decomposition

“…Upon the amalgamation of two single-layer materials to construct a heterostructure, charge transfer transpires at the interface, engendering a space charge region. This phenomenon is chiefly influenced by the work functions Φ of the two materials, defined as follows: 22 Φ = E v − E f where E v and E f represent the vacuum energy level and Fermi level, respectively. As depicted in Fig.…”

“…16–18 This heterostructure exhibits robust redox capabilities, and its distinctive Z-scheme carrier transport pathway facilitates the accumulation of electrons and holes on distinct monolayer surfaces, thereby enhancing the photocatalytic efficiency. 19–23 Additionally, the direct Z-scheme heterostructure photocatalyst exhibits a straightforward structure, facilitating its facile synthesis. 24…”