C₇N₆/Sc₂CCl₂ Weak van der Waals Heterostructure: A Promising Visible-Light-Driven Z-Scheme Water Splitting Photocatalyst with Interface Ultrafast Carrier Recombination

Abstract

Designing and characterizing high-efficiency direct Z-scheme photocatalysts both from theoretical and experimental aspects still remain a big challenge. Here, based on extensive first-principles calculations combined with excited state dynamics simulations, we report that a weak van der Waals (vdW) C7N6/Sc2CCl2 heterostructure is a mediator-free direct Z-scheme photocatalyst for solar water splitting. Theoretical results clearly reveal that this heterostructure displays a nice light-harvesting performance extending to the near-infrared region. The relatively strong interfacial non-adiabatic coupling accelerates the interlayer carrier recombination in the time scale of sub-picoseconds. The well separated electrons and holes with a strong redox capacity make the hydrogen evolution reaction spontaneously occur on the C7N6 surface and the oxygen evolution reaction on the Se-doped Sc2CCl2 surface, respectively, when the proposed heterostructure is radiated with solar light.

Hybrid density functional study on band structure engineering of ZnS(110) surface by anion–cation codoping for overall water splitting

“…In general, the OER process can be clarified by a four-step mechanism 73–75 and the corresponding elementary steps as follows:H 2 O + * → OH* + H + + e − ,OH* → O* + H + + e − ,O* + H 2 O → OOH* + H + + e − ,OOH* → * + O 2 + H + + e − .…”

Recent Progress in Computational Design of Single-Atom/Cluster Catalysts for Electrochemical and Solar-Driven N2 Fixation

“…However, the calculation of NRR activities of different mono- and bilayers (reported to be active photocatalysts through static electronic structure calculations) through NAMD simulations is yet to be performed. The rational design of direct Z-scheme photocatalysts using NAMD simulations is an active field of research for photocatalytic water splitting reactions. − However the rational design of a Z-scheme photocatalyst for the nitrogen reduction reaction using NAMD coupled with DFT is still scarce. Therefore, investigating the photophysical activities during the photocatalytic NRR is expected to be a fruitful area for future research.…”

First-Principles Calculations of Two-Dimensional CdO/HfS2 Van der Waals Heterostructure: Direct Z-Scheme Photocatalytic Water Splitting

“…Furthermore, the Z-scheme photocatalyst is popular because of its extraordinary optical carrier moving path, which can provide more efficient photocatalytic performance. For example, the 2D C 7 N 6 /Sc 2 CCl 2 heterostructure possesses ultrafast carrier recombination of about 0.74 ps, suggesting a strong redox capacity for water splitting ( Meng et al, 2022 ). Z-scheme PtS 2 /arsenene heterostructure shows a novel high solar-to-hydrogen efficiency of about 49.32% ( Ren et al, 2020b ).…”