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

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.