Achieving a Simultaneous Charge- and Energy-Involved Dual-Channel Mechanism in Spirobifluorene-Based Conjugated...

Area of Science:

• Materials Science
• Photocatalysis
• Organic Chemistry

Background:

• Current photocatalysts primarily focus on charge separation for H2O2 generation, neglecting energy-involved processes.
• Integrating both charge- and energy-involved mechanisms in a single photocatalyst for dual-channel H2O2 production is challenging but promising.

Purpose of the Study:

• To develop a conjugated organic polymer (COP) with a dual-channel mechanism for efficient H2O2 photosynthesis.
• To investigate the role of spirobifluorene and microenvironment engineering in enhancing photocatalytic performance.

Main Methods:

• Synthesized conjugated organic polymers (COPs) using spirobifluorene for orthogonal carrier transport.
• Engineered the microenvironment to enhance intersystem crossing and triplet excited state formation.
• Utilized pyridine as a cross-linker in the TBSF-Py COP.

Main Results:

• The TBSF-Py COP exhibited the lowest exciton binding energy and longest exciton lifetime, promoting singlet oxygen (1O2) generation.
• Achieved a H2O2 production rate of 7.21 mmol g-1 h-1 with a solar-to-chemical conversion (SCC) efficiency of 1.88%.
• Demonstrated robust performance in various conditions, including solar light, triphasic floating, and continuous-flow systems, with significant antimicrobial activity.

Conclusions:

• TBSF-Py effectively enables dual-channel H2O2 photosynthesis via charge- and energy-involved mechanisms.
• The developed photocatalyst shows significant potential for small-scale and household applications requiring mM-level H2O2 production.
• Presents a viable design strategy for organic photocatalysts for efficient H2O2 synthesis.