Details

Autor(en) / Beteiligte

• Shen, Yi
• Yao, Yanchi
• Lu, Lun
• Zhu, Chao
• Fang, Qile
• Wang, Jun
• Song, Shuang

Titel

Insights into dual effect of missing linker-cluster domain defects for photocatalytic 2e− ORR: Radical reaction and electron behavior

Ist Teil von

• Chemosphere (Oxford), 2023-05, Vol.324, p.138220-138220, Article 138220

Ort / Verlag

England: Elsevier Ltd

Erscheinungsjahr

2023

Quelle

MEDLINE

Beschreibungen/Notizen

• Photocatalytic 2e− ORR paves a promising avenue for hydrogen peroxide (H2O2) production. However, the obscure structure-activity relationship between a specific structure and photocatalytic 2e− ORR restricts the understanding of its intrinsic mechanism. In this work, Metal-Organic Frameworks (MOFs) with missing linker-cluster domain (MLCD) defects were employed as a model to shed new light on the effect of MLCD defect on photocatalytic 2e− ORR, which mainly focused on the radical reaction and electron behavior. Experiments and theoretical calculations revealed that incorporating MLCD defects significantly lowered the contribution rate of reactive superoxide radical (·O2−). Meanwhile, the retarded interfacial charge transfer via “Ti–O″ bridge was caused by the undesirable electron dissipation and augmented orbital-limited resistance induced by electron spin polarization. Therefore, the photocatalytic 2e− ORR activity was decreased to 30% of its origin by construction MLCD defects. This study provides insights into the internal mechanism of photocatalytic 2e− ORR for designing and optimizing excellent defective nanomaterials. The successive two-step ORR pathway suffered drastic obstruction, which was due to the delayed charge transfer and negatively altered electron configuration induced by MLCD defect. Marginalized defective cluster showed undesirable electron dissipation and the augmented orbital-limited resistance induced by electron spin polarization, which was unfavorable for O2 activation. Meanwhile, the intrinsic mechanism of photocatalytic H2O2 production in defective systems was comprehensively clarified by radical contribution quantification and electron spin structure analysis. [Display omitted] •NTU-9 with MLCD defects was developed to investigate photocatalytic 2e− ORR.•Selectivity of successive two-step ORR pathway involving ·O2− was decreased.•Undesirable electron dissipation hindered O2 activation.•Orbital-limited resistance was induced by spin polarization.