RESUMO
Artificial photoreduction of CO2 to chemical fuel is an intriguing and reliable strategy to tackle the issues of energy crisis and climate change simultaneously. In the present study, we rationally constructed a Ni(OH)2-modified covalent triazine-based framework (CTF-1) composites to serve as cocatalyst ensemble for superior photoreduction of CO2. In particular, the optimal Ni(OH)2-CTF-1 composites (loading ratio at 0.5 wt%) exhibited superior photocatalytic activity, which surpassed the bare CTF-1 by 33 times when irradiated by visible light. The mechanism for the enhancement was systematically investigated based on various instrumental analyses. The origin of the superior activity was attributable to the enhanced CO2 capture, more robust visible-light response, and improved charge carrier separation/transfer. This study offers an innovative pathway for the fabrication of noble-metal-free cocatalysts on CTF semiconductors and deepens the understanding of photocatalytic CO2 reduction.
RESUMO
Seeking efficient visible-light-driven photocatalysts for water splitting to produce H2 has attracted much attention. Chemical doping is an effective strategy to enhance photocatalytic performance. Herein, we reported phosphorus-doped covalent triazine-based frameworks (CTFs) for photocatalytic H2 evolution. Phosphorus-doped CTFs were fabricated by a facile thermal treatment using easily available red phosphorus as the external phosphorus species. The introduction of phosphorus atoms into the frameworks modified the optical and electronic property of CTFs, thus promoting the generation, separation, and migration of photoinduced electron-hole pairs. Consequently, the photocatalytic H2-production efficiency of phosphorus-doped CTFs was greatly improved, which was 4.5, 3.9, and 1.8 times as high as that of undoped CTFs and phosphorus-doped g-C3N4 calcined from melamine and urea, respectively.