One-step fabrication of unique 3D/2D S, O-doped g-C3N4 S-scheme isotype heterojunction for boosting CO2 photoreduction

Abstract

Solar irradiation-based CO2 conversion to energy-rich products is an efficient way to reduce excessive CO2 emissions and solve resource depletion. Unfortunately, achieving a cost-effective and dependable method for converting CO2 is still a significant challenge. Here, we introduce a hydrothermal approach followed by calcination to design a new-fashioned 3D S-doped g-C3N4/2D O-doped g-C3N4 (3D/2D SOCN) based step-scheme (S-scheme) heterojunction as an efficient photocatalysts for CO2 reduction. The adjusted sample demonstrated significantly greater CO2 photoreduction conversion rates compared to the blank control, including 3D S-doped g-C3N4 (3D SCN), 2D O-doped g-C3N4 (2D OCN), and bulk g-C3N4 (CN). The exceptional photocatalytic performance can be ascribed to multiple factors, including the S-Scheme isotype heterojunction that suppresses the recombination of photogenerated charge carriers, the material's high specific surface areas, which highly enhance the abundance of active sites, and the synergistic effect of the heteroatom as a dopant. The validity of the S-Scheme photogenerated charge transfer process is supported by measuring the work function and electron paramagnetic resonance (EPR). This research presents a practical method for fabricating multi non-metal-doped S-scheme isotype heterojunction photocatalysts that display remarkable efficiency for solar fuel conversion.