Published June 19, 2020 | Version accepted version
Journal article Open

Controllable Synthesis of Carbon Nitride Films with Type-II Heterojunction for Efficient Photoelectrochemical Cells

  • 1. Department of Chemistry and Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel

Description

A simple, straightforward growth method for polymeric carbon nitride (CN) layers on a conductive substrate, with excellent photoelectrochemical activity, owing to the formation of a type-II heterojunction by combining two distinct chemical growth methods, is reported. The first layer consists of CN prepared from the calcination of a melem–melamine (MeM) adduct; the utilization of MeM enables the preparation of a processable paste, which can be easily cast on the conductive substrate. To prepare the second layer, melamine vapor is introduced during calcination. After calcination, two well-connected CN layers with different electronic properties are formed, leading to the formation of a type-II heterojunction. The new CN films exhibit excellent photoelectrochemical properties with a photocurrent density of up to 383 μA cm–2 at 1.23 V versus reversible hydrogen electrode as well as an acceptable stability over 9 h in 10% (v/v) TEOA-containing 0.1 M KOH aqueous solution, thanks to the enhanced charge separation under illumination. Moreover, the CN films demonstrate good photoelectrochemical activity over a wide pH range, with photocurrent densities of 133, 80, and 118 μA cm–2 in 0.1 M KOH, 0.1 M Na2SO4, and 0.5 M H2SO4 aqueous solutions in the absence of any sacrificial agent, respectively.

Notes

This is the accepted version. The final version of record version on the ACS (publisher) website https://pubs.acs.org/doi/10.1021/acs.chemmater.0c01856

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Controllable Synthesis of Carbon Nitride Films with Type-II Heterojunction for Efficient Photoelectrochemical Cells with SI for publication.pdf

Additional details

Funding

MFreePEC – Controlled Growth of Lightweight Metal-Free Materials for Photoelectrochemical Cells 849068
European Commission