Search

C@Fe 2 C/TiO photocatalytic CO 2 realizes C–C coupling to produce C2 fuel mainly due to the formation of a Z-scheme heterojunction between Fe 2 C and TiO, which changes the electron transmission path, and the CO* generated by TiO induces the production of C2. [Display omitted] • A novel C@Fe 2 C/TiO ternary composite catalyst is prepared. • The catalyst exhibits high activity under simulated sunlight with main-product of C 2 H 4. • The catalyst could be excited by NIR lights. CO 2 conversion is of great industrial importance in reducing green-house effect and reusing carbon-resource. Most studies are focused on the thermocataltic CO 2 conversion, which usually performs over noble metal catalysts at high temperature and pressure. Recently, photocatalytic CO 2 conversion has caused increasing attention owing to the energy save, low-cost and clean reaction route. The key problem is to design photocatalysts high activity and strong durability. Here, we choose to prepare a novel C@Fe 2 C/TiO ternary composite catalyst by reducing organic compounds under an ammonia atmosphere. During CO 2 reduction reaction in aqueous solution, the catalyst exhibits high activity under simulated sunlight with main-product of C 2 H 4 (35.483 μmol g-1h−1). Even irradiating with near-infrared lights, the catalytic conversion still proceeds successfully, but the main-product turns to be CH 4 (18.315 μmol g-1h−1). Based on the chanracterizations and DFT calculation, the high activity could be attributed to the cooperation between the Fe 2 C catalyst toward C 2 H 4 and the TiO 2 photocatalyst. Specially, C@Fe 2 C/TiO could be excited by NIR lights owing to the narrow-energy band gap. More importantly, the photoelectrons could be easily separated from holes owing to the presence of the Z-scheme heterojunctions, leading to the enhanced photocatalytic activity. This work provides new insights to understand the CO 2 reduction reaction mechanism to develop photocatalysts. [ABSTRACT FROM AUTHOR]

Ionic porous organic polymers with high surface area and desirable ionic density are obtained by crosslinking strategy and these polymers have shown remarkable catalytic performance for the cycloaddition reaction of CO 2 with epoxides under mild conditions. [Display omitted] • Crosslinking strategy is proposed to improve the specific surface area of IPOPs. • IPOP1-XL and IPOP2-XL are successfully synthesized by crosslinking strategy. • IPOP1-XL and IPOP2-XL both possess excellent porosity and preferable ionic density. • IPOP1-XL shows remarkable catalytic performance in CO 2 chemical fixation. Ionic porous organic polymers (IPOPs) emerge as porous networks with charged characteristics for versatile applications. However, most of the reported IPOPs have suffered from poor porosity due to the presence of electric charges in the synthesis process. Until now, it is a challenge to obtain IPOPs with both great porosity and high ionic density. Herein, we demonstrate a simple crosslinking strategy to integrate large specific surface area and abundant ionic sites in IPOPs (named as IPOPs-XL). Especially, IPOP1-XL synthesized via crosslinking strategy exhibits a large Brunauer–Emmett–Teller (BET) specific surface area of 1830 m2 g−1, which is 18 times higher than that of the pyridine-based polymer before crosslinking (IPOP-1, 96 m2 g−1). The uptake capacity for carbon dioxide (CO 2) of IPOP1-XL (11.7 wt%) is also much higher than that of IPOP-1 (4.5 wt%) at 273 K due to the enhanced porosity. Meanwhile, IPOP1-XL also possesses an improved ionic density (3.5 mmol g−1), which plays a pivotal role in CO 2 chemical fixation. This work provides a feasible method to improve the porosity of IPOPs. [ABSTRACT FROM AUTHOR]