2026-10-14T20:39:32Z https://www.scidb.cn/oai

10.57760/sciencedb.cjcatal.00043 2026-08-05T17:23:30Z

2026-08-05 Methyl steric–hindrance–induced twisted acridine–based conjugated porous polymers for efficient 1O2–driven photocatalytic H2O2 production doi:10.57760/sciencedb.cjcatal.00043 en The effective generation and utilization of singlet oxygen (1O2) offers a promising yet challenging route for photocatalytic hydrogen peroxide (H2O2) production. In this work, we describe a molecular engineering strategy regulated by steric hindrance to control excitonic behavior and oxygen activation pathways in conjugated porous polymers (CPPs). When methyl groups are introduced into the acridine linker (from acriflavine to acridine yellow G), a planar CPP–A converts into a twisted CPP–G which has an approximately 65° dihedral angle. This change in conformation drastically alters the photophysical properties. The planar structure of CPP–A facilitates exciton dissociation and results in the development of superoxide radical (O2•-) via charge transfer. Conversely, the twisted conformation of CPP–G assists in enhancing spin–orbit coupling and intersystem crossing efficiency. These lead to an accumulation of triplet excitons and dominant 1O2 generation through energy transfer. The electrophilic 1O2 possesses a lower adsorption energy barrier on the photocatalyst surface, favoring subsequent proton–coupled electron transfer reactions. Consequently, 1O2–dominated CPP–G exhibits a remarkable H2O2 production rate of 8.97 mmol g-1 h-1 in pure water without sacrificial agents, significantly outperforming the O2•-–dominated CPP–A (5.13 mmol g-1 h-1). Furthermore, CPP–G demonstrates high efficiency and selectivity in 1O2–mediated organic transformations. This work demonstrates that steric hindrance engineering serves as a generalizable strategy, enabling a fundamental shift in the reactive oxygen species generation pathway, from charge transfer to energy transfer, via simple structural modifications in metal–free CPP photocatalytic systems. conjugated porous polymers; twisted structure; excitonic behavior; singlet oxygen; photocatalysis H2O2 production 王聪 王永慧 谭华桥 PUBLIC https://creativecommons.org/licenses/by/4.0/ dataset Science Data Bank