Coupling Strategy for CO₂Valorization Integrated with Organic Synthesis by Heterogeneous Photocatalysis

Abstract

Aus dem Inhalt 1. Introduction 21321 2. Fundamentals of Heterogeneous Photocatalytic CO 2 Valorization Integrated with Organic Synthesis 21322 3. Photocatalytic CO 2 Insertion into Organic Substrates 21326 4. Dual-Functional Reactions Coupling CO 2 Reduction with Oxidative Organic Synthesis 21330 5. Conclusions and Perspectives 21339

Photoswitchable Chlorine Vacancies in Ultrathin Bi4O5Cl2 for Selective CO2 Photoreduction

“…In general, the CO 2 photoreduction efficiency and product selectivity of a photocatalyst depend on the high carrier-separation efficiency during photocatalysis. − However, conventional photocatalysts have low light-harvesting capacities. Furthermore, their large particle sizes cause photogenerated carriers to readily recombine, resulting in low electron-transfer efficiency and undesirable CO 2 photoreduction performance. − Recently, researchers have determined that constructing ultrathin two-dimensional (2D) photocatalysts would be an effective approach for CO 2 photoreduction. The atomic-scale thickness can shorten the carrier diffusion length, thus reducing the bulk recombination of photocharge and improving the electron transport .…”

Efficient Photocatalytic CO2 Reduction with High Selectivity for Ethanol by Synergistically Coupled MXene-Ceria and the Charge Carrier Dynamics

“…Therefore, the activation of CO 2 molecules on the catalyst surface and tuning the product selectivity are vital in order to improve the yield of the desired (selective/single) product . The overall process of photocatalytic CO 2 reduction includes the generation of photogenerated electron/hole pairs by absorbing incident photons, activation of CO 2 on the photocatalyst surface (a rate-limiting step owing to the greater degree of rearrangement between the linear CO 2 molecule and bent radical anion of CO 2 •– ), and its subsequent reduction. − The photogenerated electrons should have a high reduction ability, which means that the conduction band minima should be more negative to thermodynamically drive the specific CO 2 reduction reaction and the better separation of photogenerated charge carriers can accelerate the rate of the multielectron reduction reaction, eventually forming higher reduced state products. It involves multiple steps with a time scale ranging from the photoinduced generation of electron and hole pairs (fs–ps scale), their transport to the photocatalyst surface (ps−μs scale), and the surface catalytic reaction.…”

Boosting Photocatalytic CO2 Reduction with H2O by Oxygen Vacancy- and Hydroxyl-Tailored SrBi2Ta2O9 Surface-Frustrated Lewis Pairs

“…Carbon dioxide (CO 2 ) released by fossil fuel combustion is considered a serious threat to humans and the environment on Earth. − Photocatalytic CO 2 conversion is regarded as a potential solution to alleviate environmental problems, utilize solar energy, and produce high-value carbon-based fuels. − Among the various candidates, semiconductor-based photocatalysts have witnessed tremendous development in the past decades owing to their economic, nontoxic, and renewable properties. − However, the photocatalytic CO 2 conversion efficiency over semiconductors is significantly limited by the stability of the linear CO 2 molecule and the significantly high CO bond energy (806 kJ mol –1 ). − In general, CO 2 photoreduction is a typical heterogeneous catalytic process, where efficient interfacial adsorption and activation on the surface is a pivotal prerequisite for CO 2 conversion. − Therefore, precise tailoring of the surface sites of catalysts at the atomic level is crucial to facilitating CO 2 activation.…”