Atomic-Layer Controlled Interfacial Band Engineering at Two-Dimensional Layered PtSe2/Si Heterojunctions for Efficient Photoelectrochemical Hydrogen Production
Journal
ACS Nano
Journal Volume
15
Journal Issue
3
Pages
4627-4635
Date Issued
2021
Author(s)
Abstract
Platinum diselenide (PtSe2) is a group-10 two-dimensional (2D) transition metal dichalcogenide that exhibits the most prominent atomic-layer-dependent electronic behavior of "semiconductor-to-semimetal"transition when going from monolayer to bulk form. This work demonstrates an efficient photoelectrochemical (PEC) conversion for direct solar-to-hydrogen (H2) production based on 2D layered PtSe2/Si heterojunction photocathodes. By systematically controlling the number of atomic layers of wafer-scale 2D PtSe2 films through chemical vapor deposition (CVD), the interfacial band alignments at the 2D layered PtSe2/Si heterojunctions can be appropriately engineered. The 2D PtSe2/p-Si heterojunction photocathode consisting of a PtSe2 thin film with a thickness of 2.2 nm (or 3 atomic layers) exhibits the optimized band alignment and delivers the best PEC performance for hydrogen production with a photocurrent density of -32.4 mA cm-2 at 0 V and an onset potential of 1 mA cm-2 at 0.29 V versus a reversible hydrogen electrode (RHE) after post-treatment. The wafer-scale atomic-layer controlled band engineering of 2D PtSe2 thin-film catalysts integrated with the Si light absorber provides an effective way in the renewable energy application for direct solar-to-hydrogen production. ?
Subjects
Alignment; Atoms; Chemical vapor deposition; Entertainment industry; Field emission cathodes; Film thickness; Heterojunctions; Photocathodes; Photocurrents; Photoelectrochemical cells; Platinum compounds; Selenium compounds; Silicon wafers; Thin films; Transition metals; Chemical vapor depositions (CVD); Photocurrent density; Photoelectrochemical hydrogen production; Photoelectrochemicals; Renewable energy applications; Reversible hydrogen electrodes; Transition metal dichalcogenides; Two Dimensional (2 D); Hydrogen production
SDGs
Other Subjects
Alignment; Atoms; Chemical vapor deposition; Entertainment industry; Field emission cathodes; Film thickness; Heterojunctions; Photocathodes; Photocurrents; Photoelectrochemical cells; Platinum compounds; Selenium compounds; Silicon wafers; Thin films; Transition metals; Chemical vapor depositions (CVD); Photocurrent density; Photoelectrochemical hydrogen production; Photoelectrochemicals; Renewable energy applications; Reversible hydrogen electrodes; Transition metal dichalcogenides; Two Dimensional (2 D); Hydrogen production
Type
journal article