The growth of 2D crystalline g-C3N4 films and the control of optoelectronic properties

TL;DR

This paper reports the synthesis of high-quality 2D crystalline g-C3N4 films with controlled optoelectronic properties, achieved through chemical vapor deposition and precursor modification, enhancing its potential for photocatalytic applications.

Contribution

The study demonstrates a novel method for growing 2D crystalline g-C3N4 films with tunable properties, addressing previous synthesis challenges and providing insights for improved photocatalytic performance.

Findings

Successful growth of 2D g-C3N4 films up to 100 nm thick

Identification of optimal growth conditions via spectroscopic analysis

Band gap modulation achieved by N vacancies through precursor modification

Abstract

g-C3N4 is a novel semiconductor photocatalyst material; however, the low specific surface area and rapid carrier compliance hinder its photocatalytic performance. On the other hand, the synthesis of 2D g-C3N4 with high crystallinity remains challenging. Here, we report the growth of 2D crystalline g-C3N4 films with thicknesses up to 100 nm on the indium tin oxide substrates by chemical vapor deposition. The films show high quality, as shown by scanning electron microscopy and X-ray diffraction, and exhibit intense fluorescence at room temperature. The optimal growth conditions, such as temperature and carrier gas flow rate, were achieved by analyzing their effects on the electronic structure through X-ray absorption spectra and X-ray photoelectron spectroscopy. By adding thiourea to the melamine precursors, we introduced N vacancies to achieve band gap modulation and promote carrier separation. This work provides guidelines for the further improvement of g-C3N4 performance and for extending its application in the field of photocatalytic devices.