Two-Dimensional ZnS/SnS2 Heterojunction as a Direct Z-Scheme Photocatalyst for Overall Water Splitting: A DFT Study

Abstract

Direct Z-scheme photocatalysts have attracted extensive attention due to their strong redox ability and efficient separation of photogenerated electron-hole pairs. In this study, we constructed two types of ZnS/SnS2 heterojunctions with different stacking models of ZnS and SnS2 layers, and investigated their structures, stabilities, and electronic and optical properties. Both types of heterojunctions are stable and are direct Z-scheme photocatalysts with band gaps of 1.87 eV and 1.79 eV, respectively. Furthermore, their oxidation and reduction potentials straddle the redox potentials of water, which makes them suitable as photocatalysts for water splitting. The built-in electric field at the heterojunction interface improves the separation of photogenerated electron-hole pairs, thus enhancing their photocatalytic efficiency. In addition, ZnS/SnS2 heterojunctions have higher carrier mobilities and light absorption intensities than ZnS and SnS2 monolayers. Therefore, the ZnS/SnS2 heterojunction has a broad application prospect as a direct Z-scheme visible-light-driven photocatalyst for overall water splitting.

Interstitial/Substitutional Se Doping in Nanosheet Heterostructures for Sensing NH3: Experimental and Theoretical Study

“…The adsorption energy ( E ad ) and charge transfer ( Q ) values of undoped and Se codoped SnS/SnS 2 systems are also calculated to clarify the adsorption stability and electronic properties variation (as seen in Table ). The E ad was calculated by the Formula E ad = E sub + gas − E sub − E gas where E sub , E gas , and E sub+gas represent the total energy of heterostructure, gas molecule, and heterostructure adsorbed by the gas molecule, respectively. By definition, a more negative value of E ad indicates a stronger interaction between the gas molecule and surface.…”

“…52 The adsorption energy (E ad ) and charge transfer (Q) values of undoped and Se codoped SnS/SnS 2 systems are also calculated to clarify the adsorption stability and electronic properties variation (as seen in Table 1). The E ad was calculated by the Formula 2 53 E E E E ad sub gas sub gas…”

Evaluation of zinc sulfide heterostructures as catalysts for the transformation of CO2 into valuable chemicals and clean energy generation

“…The holes, however, can take part in the oxidation of water to form oxygen molecules and hydroxyl radicals and can also convert organic pollutants into CO 2 and H 2 O. 87,88 Furthermore, the efficiency of a photocatalytic material mainly depends on the type of material it is made up of. The energy values of the CB and VB influence the photocatalytic properties of the photocatalyst, and this in turn can affect the efficiency of the photocatalyst.…”

Materials Design and Development of Photocatalytic NOx Removal Technology

“…In Z-scheme configurations, reduction semiconductors absorb light and generate electrons, which are subsequently accepted by oxidation semiconductors, leading to sustained photocatalysis [41][42][43]. Similarly, S-schemes exploit built-in electric fields at semiconductor interfaces to facilitate efficient charge carrier migration, enhancing redox capacity [40,42].…”