Selective photoreduction of carbon dioxide to formic acid using Cs3Bi2Cl9–Ir/IrOx hybrid materials

Abstract

Tuning the selectivity and improving the activity of photocatalysts are among the main bottlenecks for the conversion of CO₂ to value-added chemicals. Recently, lead-free halide perovskites have been extensively investigated as photocatalysts for the photoreduction of CO₂. Herein, we report a composite photocatalyst using Cs₃Bi₂Cl₉ and Ir/IrO_x for the photoreduction of CO₂. The hybrid photocatalyst Cs₃Bi₂Cl₉–Ir/IrO_x displayed a high selectivity towards HCOOH formation with a yield of 158 ± 9 μmol g⁻¹ h⁻¹, suppressing the formation of carbon monoxide. This is the highest yield of HCOOH reported for this class of materials. In this work, we discuss the effective strategy of combining halide perovskites with simple iridium-based catalysts for enhanced and selective photoreduction of CO₂ to HCOOH.