Nitrogen Source-Regulated Biomass-Based COF@CNF Aerogel: Achieving Efficient Photothermal-Photocatalytic Synergy

Abstract

The scarcity of freshwater resources and the increasing demand for high-value chemicals have positioned solar-driven energy conversion technologies that integrate efficient photothermal conversion with photocatalytic reactions as key solutions. In this context, COFs have demonstrated unique advantages in bimodal energy conversion.Based on this, a synergistic strategy of "macro-oriented structure and micro-molecular design" is proposed to construct two porous COF@CNF aerogels (TpTt@CNF and TpHt@CNF) and their corresponding evaporators TpTt@CNF@CNT and TpHt@CNF@CNT, denoted as TCE and HCE. The two COFs (TpTt and TpHt) incorporate triazine and heptazine nitrogen sources, respectively, endowing the materials with tunable water-binding capabilities and electronic structures. Coupled solar thermal-photocatalytic experiments demonstrate that oriented 25%-HCE maintains an evaporation rate of 3.27 kg m -2 h -1 and a H2O2 production rate of 16.82 mmol m -2 h -1 under one sun irradiation. Additionally, in single-performance tests, the oriented 30%-TpHt@CNF achieved the highest hydrogen peroxide generation rate (19.4 mmol•m -2 h -1 ), while the oriented 25%-HCE exhibited the highest evaporation rate (3.46 kg m -2 h -1 ). In summary, the synergistic interaction between the macrooriented pore structure and nitrogen source regulation within the COF enables efficient coupling of photothermal evaporation and photocatalytic reactions within the same system.