Novel COF@Ti–MOF hybrid photocatalysts enabling enhanced photocatalytic CO2 reduction in a gas–solid system without additives

Abstract

With the increasing global energy demand and environmental problems, the photoreduction of CO₂ into valuable chemical materials is considered to be an ideal way to recycle carbon resources. Naturally, the design and synthesis of efficient photocatalysts used for the photocatalytic reduction of CO₂ still face great challenges. Herein, a series of stable hybrid photocatalysts TpPa@IEF has been produced by integrating the two-dimensional covalent organic framework TpPa-1 with the Ti-based metal–organic framework IEF-11. The photocatalytic performance of TpPa@IEF has been evaluated via gas–solid reaction mode under visible light as well as no sacrificial agents and photosensitizers. The experimental results show that TpPa@IEF exhibits excellent photocatalytic activity in pure and dilute CO₂ (10%) environments. The introduction of IEF-11 has resulted in a significant improvement in photocatalytic performance; TpPa@IEF achieved a great CO generation rate of 78.87 μmol g⁻¹ h⁻¹ in pure CO₂, notably, and obtained another excellent CO generation rate of 116.47 μmol g⁻¹ h⁻¹ in dilute CO₂ (10%), which are 3.63 and 4.93 times higher than that of TpPa-1, respectively. The excellent photocatalytic performance of TpPa@IEF hybrids stems from the high charge separation efficiency and CO₂ capture ability, as well as the abundant catalytic active sites. The preparation of TpPa@IEF hybrid materials presents a novel perspective for the design and synthesis of efficient photocatalysts.