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Imine-linked covalent organic frameworks (COFs) have been widely studied in the field of photocatalytic hydrogen production due to their easy synthesis, good crystallinity, tunable pore size and excellent thermal and chemical stability. However, the effect of substituent type on the photocatalytic properties of COFs has been rarely studied. Herein, six COFs with COF-TpPa as the basic skeleton were synthesized by introducing different types of substituents in the p-phenylenediamine benzene ring, among which TpPa-CN2 was prepared for the first time. The COFs showed similar structures but great differences in their photoelectric properties. TpPa-Cl2 and TpPa-CN2 demonstrated a superior hydrogen evolution performance compared to the other four COFs when ascorbic acid was used as the electron sacrificial agent and Pt as the cocatalyst. The photocatalytic hydrogen evolution (PHE) rate of TpPa-Cl2 and TpPa-CN2 was as high as 99.23 and 76.93 mmol g−1 h−1, respectively. The introduction of chlorine and cyanide improved the visible-light response, hydrophilicity and photo-carrier separation ability of TpPa COF, which contributed to the enhanced PHE efficiency of TpPa-Cl2 and TpPa-CN2. This study provides a strong basis for the systematic fine-tuning of the structural and physico-chemical properties of COFs aiming to achieve COF materials with ultra-high photocatalytic activity. [ABSTRACT FROM AUTHOR]

The decline in female fertility as age advances is intricately linked to the diminished developmental potential of oocytes. Despite this challenge, the strategies available to enhance the quality of aged oocytes remain limited. Epigallocatechin‐3‐gallate (EGCG), characterised by its anti‐inflammatory, antioxidant and tissue protective properties, holds promise as a candidate for improving the quality of maternally aged oocytes. In this study, we explored the precise impact and underlying mechanisms of EGCG on aged oocytes. EGCG exhibited the capacity to enhance the quality of aged oocytes both in vitro and in vivo. Specifically, the application of EGCG in vitro resulted in noteworthy improvements, including an increased rate of first polar body extrusion, enhanced mitochondrial function, refined spindle morphology and a reduction in oxidative stress. These beneficial effects were further validated by the improved fertility observed among aged mice. In addition, our findings propose that EGCG might augment the expression of Arf6. This augmentation, in turn, contributes to the assembly of spindle‐associated F‐actin, which can contribute to mitigate the aneuploidy induced by the disruption of spindle F‐actin within aged oocytes. This work thus contributes not only to understanding the role of EGCG in bolstering oocyte health, but also underscores its potential as a therapeutic intervention to address fertility challenges associated with advanced age. [ABSTRACT FROM AUTHOR]