Biomimetic chlorophyll derivatives-based photocatalytic fabric for highly efficient O₂ production via CO₂ and H₂O photoreaction

As global warming and greenhouse gas emissions intensify, the scientific community is continuingly seeking effective solutions. One promising strategy known as artificial photosynthesis is proposed utilizing H₂O as a reducing agent to transfer CO₂ into fuel. However, low O₂ production and conversion efficiency have hindered this approach in matching with natural photosynthesis. In this work, we propose a novel biomimetic photocatalyst design approach to improve the catalytic efficiency by slow photon mechanism. Our design is mainly inspired by two factors: 1) Chlorophyll, an abundant natural photosynthetic pigment, can efficiently and selectively reduce carbon dioxide and plays a key role in photosynthesis; 2) The iridoplast with a biological photonic crystal structure can significantly improve the efficiency of photosynthesis. Specifically, we couple photonic crystals and photocatalyst of sodium copper chlorophyllin (ChlCu), and binder of PVA through microfluidic blowing-spinning (MBS) to spray a composite photocatalytic film that can convert carbon dioxide and water into carbon monoxide and oxygen. By optimizing the content of ChlCu and the slow photon effect related to the bandgap position, the final CLPPs₃₀₀-0.52% has two slow photon edges overlapping with the catalyst absorption spectrum, thus generating the maximum photon capture capability and achieving a high oxygen catalytic yield of up to 7.8 mmol g^-1h⁻¹. The spraying property of this material enable it to be coated on the external surfaces of other materials. This opens new possibilities of photocatalytic fabric preparation for CO₂ converting, providing new ideas of greenhouse gas capture and utilization to solve environmental problems.