The temperature-controlled optimization of g-C3N4 structure significantly enhances the efficiency of photothermal catalytic NO removal

Abstract

The efficiency of photocatalytic NO removal is often constrained by catalyst lifespan and secondary contamination from reaction products. Therefore, in this study, g-C₃N₄ (CN) was incorporated into a photothermal reaction system for synergistic NO removal via photothermal effects. It was observed that increasing the temperature led to a 19% enhancement in CN's photocatalytic removal efficiency, with a selectivity of 96.8% towards NO₂ generation. Additionally, the catalyst's lifespan increased by 2.85 times, while the quantum yield rose from 1.54% to 2.22%. This study also provides novel insights into the mechanism of photothermal synergy: (1) high temperatures facilitate more efficient capture of O₂ by hot electrons, promoting ˙O₂⁻ generation; (2) the catalyst structure is regulated by temperature elevation, as hot electrons promote greater n → π* transfer on CN, which is favorable for electron–hole separation and transfer. As a result, CN-based photothermal collaborative catalysis shows promising prospects for NO removal.