Work

Photocatalytic and surface consequences of thermal treatments on Pt nanoparticles onto carbon nitrides during CO2-to-CO conversion

Year: 2025

Type: article

Abstract: Photocatalysis is an emerging alternative to convert CO 2 into relevant products, but it faces technological challenges related to charge recombination and low efficiency. Thermally coupled gas phase photocatalysis can address these issues by lowering reaction temperatures and improving process efficiency. This work demonstrates that defect engineering, combined with Pt impregnation at various metal dispersion and sizes, can enhance photocatalytic properties in g-C 3 N 4 materials. Structural changes in g-C 3 N 4 and Pt oxidation state modification, significantly impact CO productivity from CO 2 . This study investigates how thermal treatments in H 2 affect defect and thus vacancy formation in g-C 3 N 4 . Materials with 2 wt% Pt 2 + species generate C–N 3 vacancies, while Pt 0 species with the same content lead to both C–N 3 and N–C 3 vacancies– within g-C 3 N 4 . These differences exhibit distinct reaction trends under dark conditions or upon light irradiation. To further understand these effects, detailed XPS analyses clarify the impact of reaction conditions on the material after pretreatment and catalysis. The findings show that g-C 3 N 4 materials can reform their C–Nbonds after electron excitation through light exposure, enhancing and stabilizing the reaction's productivity. As a result, CO productivities up to 1.1 mmol·g cat −1 ·h −1 are achieved. This work is expected to contribute to understanding the effect of thermal treatment on carbon nitrides, particularly regarding defect engineering, and more broadly, the effects of temperature in photocatalysis. • Thermal treatment enhances the photocatalytic properties of g-C 3 N 4 . • CO 2 photoreduction with g-C 3 N 4 doped with Pt achieved 100 % selectivity. • Smaller Pt NPs and metallic Pt boost photocatalysis over the Pt +2 state. • Temperature improves charge transfer and enhances photocatalytic performance. • Continuous gas-phase photocatalysis g-C 3 N 4 2 % Pt 0 reached 1.1 mmol·g −1 ·h −1 of CO.

Source: Journal of CO2 Utilization

DOI: 10.1016/j.jcou.2025.103068

Authors: S. Vaquero-Vílchez, P. Nimax, E. Valtierra-Martinez, I. Ayesta, I. Agirrezabal-Telleria

Institution: University of the Basque Country

Language: English

Topic: Advanced Photocatalysis Techniques

Subfield: Renewable Energy, Sustainability and the Environment

Field: Energy

Domain: Physical Sciences

SDGs: Affordable and clean energy, Climate action

Open Access status: gold

Estimated APC paid: $3,360