Two-step polymerization nanoarchitectonics for superior thin g-C3N4 nanosheets with modulated band gap and enhanced photo- and electro-chemical performance

The photo and electro catalytic activity of graphic carbon nitride (g-C3N4) depended strongly on the component, band gap, and thickness. In this paper, superior thin g-C3N4 composition homojunctions were created via a seed growth process by controlling precursor components. The result exhibited the change of microstructure, band gap, and photo and electro chemical properties of samples. Photocatalytic H2 generation and the photodegradation of rhodamine B (Rh B) were carried out to test photocatalytic activities. gC3N4 seeds were fabricated using melamine and dicyandiamide named as MCN and DCN, respectively. The homojunctions were fabricated by the thermal polymerization of dicyandiamide using MCN as seeds. Because of a type II structure and high stability, sample 600MCN@720DCN10% revealed the best H2 generation which was-20 times of that of g-C3N4 nanosheets. The photocatalytic degradation of Rh B was completed within 15 min using this homojunction sample. In contrast, the homojunctions fabricated by the thermal polymerization of melamine using DCN as seeds revealed enhanced electrochemical performance. Sample 600DCN@720MCN exhibited the lowest overpotential and the best H2 evolution reaction performance. The result suggested the formation of homojunction improves photo and electrocatalytic activities.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

This paper demonstrates the synthesis of high-quality thin g-C3N4 homojunctions by controlling precursor components during the seed growth process. The resulting samples showed changes in microstructure, band gap, and photoelectrochemical properties. Photocatalytic activities were tested through H2 generation and the photodegradation of Rhodamine B (Rh B). The formation of homojunctions improves the photoelectrocatalytic activities.