Insights from density functional theory calculations on heteroatom P-doped ZnIn2S4 bilayer nanosheets with atomic-level charge steering for photocatalytic water splitting

Abstract

ZnIn2S4 (ZIS) is an efficient photocatalyst for solar hydrogen (H2) generation from water splitting owing to its suitable band gap, excellent photocatalytic behaviour and high stability. Nevertheless, modifications are still necessary to further enhance the photocatalytic performance of ZIS for practical applications. This has led to our interest in exploring phosphorus doping on ZIS for photocatalytic water splitting, which has not been studied till date. Herein, phosphorus-doped ZnIn2S4 (P-ZIS) was modelled via Density Functional Theory to investigate the effects of doping phosphorus on the structural and electronics properties of ZIS as well as its performance toward photocatalytic water splitting. This work revealed that the replacement of S3 atom by substitutional phosphorus gave rise to the most stable P-ZIS structure. In addition, P-ZIS was observed to experience a reduction in band gap energy, an upshift of valence band maximum (VBM), an increase in electron density near VBM and a reduction of H* adsorption–desorption barrier, all of which are essential for the enhancement of the hydrogen evolution reaction. In overall, detailed theoretical analysis carried out in this work could provide critical insights towards the development of P-ZIS-based photocatalysts for efficient H2 generation via solar water splitting.

High-performance hierarchical O-SnS/I-ZnIn2S4 photodetectors by leveraging the synergy of optical regulation and band tailoring

“…It is evident that ZIS has a direct bandgap at the Γ point whereas SnS has an indirect bandgap, which are consistent with previous studies. 61,62 Of note, the direct bandgap nature of ZIS is beneficial to enhance the light–matter interactions while the indirect bandgap nature of SnS contributes to extend the excess carrier lifetime. The synergy of them is conducive to improving the device performance.…”

Ultra-high photoelectric conversion efficiency and obvious carrier separation in photovoltaic ZnIn2X4 (X = S, Se, and Te) van der Waals heterostructures

“…12,13 Besides, the photoelectric conversion efficiency of single-junction solar cells is limited by the Shockley–Queisser (SQ) model, 14,15 whose maximum conversion efficiency is about 33%. 3,14 ZnIn 2 S 4 (ZIS) is a kind of direct bandgap semiconductor with a bandgap of 2.34 eV, 16 with enormous potential applications in many fields such as charge storage, 17 thermoelectricity, 18 lithium batteries, 19 photocatalysis, 20–29 and solar cell. 30–33 In 2003, Lei et al first reported photocatalytic hydrogen evolution using ZIS.…”

“…20 After that Yang et al found that doping oxygen in ZIS can increase the average lifetime of the photo-induced electrons by 1.53 times, which is a strong evidence of carrier separation. 21 The non-metallic nitrogen 22 and sulfur doping 23 also can provide more reducing photo-generated electrons and lead to high photocatalytic activity. Besides, silver ion interstitial and doping in ZIS introduced acceptor state and donor state, respectively, which greatly increased the carrier density and charge transfer efficiency, thus enhancing the activity of the photocatalytic hydrogen evolution.…”

Interface and Defect Engineering of a Hollow TiO2@ZnIn2S4 Heterojunction for Highly Enhanced CO2 Photoreduction Activity

“…With a small band gap of ∼2.4 eV, the ternary sulfide ZnIn 2 S 4 is among the most promising visible-light-responsive photocatalytic materials. , However, the fast recombination of photoinduced carriers and the severe photocorrosion restrict its photocatalytic performance. To promote the charge transfer in ZnIn 2 S 4 , it is a feasible strategy to recombine it with TiO 2 with a high surface chemical activity. , Besides, it has been reported that a certain amount of sulfur vacancies can be generated in sulfides by calcination .…”