SrTiO3/Ti3C2Tx Schottky heterojunction as a promising high-efficiency photocatalyst for H2 evolution

Abstract

Exploring low-cost, high-efficiency, and stable photocatalysts is still a significant challenge. SrTiO3, one of the appealing photocatalysts, can meet most of the screening criteria except for its efficiency, which is restricted by its poor absorption of visible light and its prompt photogenerated carrier recombination. Recently, a two-dimensional transition metal carbide Ti3C2Tx (2D MXene) has been found to serve as a co-catalyst due to its excellent metallic conductivity, hydrophilic property, large specific surface area, abundance of active sites, and low reaction barrier to hydrogen production. In this work, SrTiO3 nanoparticles are rationally integrated with Ti3C2Tx nanosheets via a simple hydrothermal process. The hydrogen production rate can achieve up to 3.43 mmol g−1 h−1 in the hybridization of SrTiO3-3 wt. % Ti3C2Tx, which is almost six times that of SrTiO3 alone. This remarkable enhancement arises predominantly from the Schottky contact between SrTiO3 and Ti3C2Tx, which can effectively suppress the recombination of photogenerated carriers and accelerate their separation. In addition, such enhancement benefits from the hydrogen evolution capacity of Ti3C2Tx. This work opens an excellent prospect for constructing highly active, low-cost, and stable photocatalysts with 2D MXene and finding potential applications of 2D MXene in energy conversion fields.

Exploration of Photocatalytic Overall Water Splitting Mechanisms in the Z-Scheme SnS2/β-As Heterostructure

“…Furthermore, an excellent photocatalyst requires a small band gap to absorb more visible light, but sufficient redox potential requires a larger band gap instead. To our best knowledge, few 2D photocatalysts can spontaneously achieve overall water splitting, such as PdSeO 3 and B, N-codoped graphdiyne monolayers. , Fortunately, building van der Waals heterostructures with two staggered semiconductors may be a good strategy to address the above problems . The Z-scheme heterostructure is desirable compared to other types of heterostructures, which can effectively separate electron–hole pairs, extend the light-harvesting range, and maintain a strong redox potential …”

“…11,12 Fortunately, building van der Waals heterostructures with two staggered semiconductors may be a good strategy to address the above problems. 13 The Z-scheme heterostructure is desirable compared to other types of heterostructures, which can effectively separate electron−hole pairs, extend the lightharvesting range, and maintain a strong redox potential. 14 Recently, the SnS 2 nanosheet has been sought after by many researchers due to its unique properties and has also been synthesized experimentally by various methods.…”

The Isoelectronic Dopant in the Z-Scheme SnS2/β-As Heterostructure Enhancing Photocatalytic Overall Water Splitting

“…To address this issue, researchers have focused on improving the light-harvesting ability, carrier separation efficiency, and reaction barrier height of photocatalysts. Two-dimensional (2D) photocatalysts, such as phosphorene, , transition metal dichalcogenides (TMDs), − and MXenes, − have emerged as new photocatalytic platforms because of their high specific surface area, abundant active sites, and short carrier migration path. − However, few single photocatalysts can possess perfect catalytic performance due to the intrinsic conflict between the light harvesting capability and water redox potentials. Heterostructures constructed by two materials are excellent candidate photocatalysts, which can overcome individual materials’ inherent drawbacks and exhibit novel properties. ,, Z-scheme heterostructures, in particular, can significantly improve carrier separation efficiency and expand the light absorption range without sacrificing the redox potential. − In addition, OER is a bottleneck limiting the efficiency of the overall water splitting of photocatalysts due to the complex four-electron step path, slow kinetic process, and considerable oxidation potential. , Furthermore, there are generally multiple side-products accompanying target products .…”