Distinctive 2-D SrTiO3/g-C3N4 heterostructure photocatalyst for efficient photocatalytic water splitting reaction
Journal
Solar Energy Materials and Solar Cells
Journal Volume
303
Start Page
114389
ISSN
09270248
Date Issued
2026-08-15
Author(s)
Abstract
The g-C3N4/SrTiO3 heterojunction is a promising composite in photocatalysis since its band position is suitable for various applications. Herein, we introduce the unique two-dimensional (2D) heterostructure SrTiO3/g-C3N4, which was synthesized using a straightforward method involving the mixing and calcination of the components. The 2D SrTiO3 nanoplatelet was obtained through a topochemical conversion from Bi4Ti3O12, while the 2D g-C3N4 nanosheet was prepared via an exfoliation technique. With 5 wt% of 2D SrTiO3, the 2D heterostructure SrTiO3/g-C3N4 with Pt nanoparticles as co-catalyst exhibited superior photocatalytic hydrogen evolution, reaching 2300 μmol/g - 10300 μmol/g after 5 h under simulated sunlight - a fourfold increase compared to the corresponding starting g-C3N4 catalysts. The photocatalytic performance of both pure g-C3N4 and the heterostructures was significantly influenced by the degree of g-C3N4 exfoliation. A threefold increase in the specific surface area resulted in a fivefold increase in H2 evolution rates. This suggests that a higher surface area of g-C3N4 facilitates better contact with 2D SrTiO3, provides more active sites for reactants, and enhances light absorption. In contrast, the heterojunction catalysts, which combine g-C3N4 with cube-like SrTiO3 particles, showed inferior activity, highlighting the advantage of the 2D morphology. The results emphasize the enhanced photocatalytic activity of 2D/2D SrTiO3/g-C3N4, where the larger interfacial contact facilitates effective charge transfer and improves the separation of photo-induced charge carriers. Additionally, the overall water splitting results further validated the noteworthy performance of the optimized photocatalysts, showcasing a significant gas evolution rate. Finally, two possible mechanisms for the photocatalytic hydrogen evolution reaction in both sacrificial solution and deionized water are proposed.
Subjects
Direct Z-scheme
g-C3N4 nanosheet
H2 production
Simulated sunlight
SrTiO3 platelet
Two-dimensional photocatalyst
Publisher
Elsevier B.V.
Type
journal article