Boosted photocharge separation in copper (II) porphyrin grafted high-entropy halide perovskite for selective CO2 photoreduction

Abstract

Photocatalytic conversion of CO₂ into fossil fuel remains a challenge due to the limited CO₂ adsorption and activation capability of catalysts. High entropy alloys are emerged as a new class of catalysts in the field of energy conversion, however, the extremely high preparation temperature requirement limits their further application. In this work, we used a low-temperature solution syntheses (75 °C) to achieve a high-entropy halide perovskite catalyst and applied it in the field of CO₂ photoreduction. The ability of Cs₂Ag{InPrCeGdTb}₁Cl₆ for CO₂ photoreduction was confirmed. To further improve its photocatalytic property, the copper (II) porphyrin ligand was directly grafted on the surface of Cs₂Ag{InPrCeGdTb}₁Cl₆. The copper (II) porphyrin ligand could serve as adsorption sites to enhance the CO₂ adsorption capacity. Moreover, the photocharge carrier separation was efficiently improved via the directional transfer of electrons from catalyst to copper (II) porphyrin ligand, thus achieving a CO yield of 83.26 µmol g^-1h⁻¹ with nearly 100 % product selectivity after photocatalysis. This work provides a practical strategy for low temperature synthesizing modified high-entropy halide perovskite catalysts applied for solar energy conversion.