Reticular Covalent Organic Framework Coupled With Tetragonal BiVO ₄ Hybrid for Enhanced Photoreduction of CO ₂

ABSTRACT

Photocatalytic CO ₂ conversion is a promising strategy to mitigate CO ₂ emissions and address energy sustainability challenges simultaneously. Herein, a covalent organic framework (COF)‐decorated tetragonal bismuth vanadate (t‐BiVO ₄ ) heterostructure was fabricated via a facile in situ growth strategy for efficient photocatalytic CO ₂ reduction. t‐BiVO ₄ (BV) was formed from monoclinic BiVO ₄ (m‐BiVO ₄ ) by phase transformation, triggered by the presence of tris(2‐pyridylmethyl) amine (TpMA)‐COF. Hybrid catalysts TpMA‐BV with different TpMA concentrations (0‒20 wt%) were evaluated for CO ₂ photoreduction. The catalyst containing 10 wt% TpMA exhibited a remarkable CO production rate of 4.73 mmol g _cat ⁻¹ h ⁻¹ , greatly surpassing that of pristine m‐BiVO ₄ . The enhanced photocatalytic performance could be attributed to the synergistic effect arising from the intimate interfacial contact between TpMA and t‐BiVO ₄ . The intrinsic microporosity of TpMA‐COF facilitates CO ₂ enrichment on the surface, and t‐BiVO ₄ acts as a visible‐light‐driven electron donor. The well‐defined π‐conjugated framework of TpMA‐COF serves as an electron‐accepting platform, enabling rapid interfacial charge transfer and suppressing charge recombination. Time‐resolved in situ diffuse reflectance Fourier‐transform infrared spectroscopy (in situ DRIFTS) unraveled the reaction pathway, revealing high selectivity toward CO ₂ reduction via *COOH intermediate. The work demonstrates that integrating inorganic semiconductors with reticular COFs provides an effective heterojunction design strategy for sustainable solar‐driven CO ₂ conversion.