Photoelectrocatalytic Utilization of CO2: A Big Show of Si‐based Photoelectrodes

• Published in: Chemistry : a European journal 2024-03, Vol.30 (14), p.e202303552-n/a
• Main Authors: Yu, Jiacheng, Hao, Xue, Mu, Lixuan, Shi, Wensheng, She, Guangwei
• Format: Article
• Language: English
• Subjects: Carbon dioxide; Carbon dioxide fixation; carbon dioxide reduction; Carrier mobility; Catalysts; Chemicals; Direct reduction; Environmental degradation; Greenhouse gases; heterogeneous catalysis; photoelectrocatalytic; silicon; Substrates; Utilization
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202303552

CO2 is a greenhouse gas that contributes to environmental deterioration; however, it can also be utilized as an abundant C1 resource for the production of valuable chemicals. Solar‐driven photoelectrocatalytic (PEC) CO2 utilization represents an advanced technology for the resourcing of CO2. The key to achieving PEC CO2 utilization lies in high‐performance semiconductor photoelectrodes. Si‐based photoelectrodes have attracted increasing attention in the field of PEC CO2 utilization due to their suitable band gap (1.1 eV), high carrier mobility, low cost, and abundance on Earth. There are two pathways to PEC CO2 utilization using Si‐based photoelectrodes: direct reduction of CO2 into small molecule fuels and chemicals, and fixation of CO2 with organic substrates to generate high‐value chemicals. The efficiency and product selectivity of PEC CO2 utilization depends on the structures of the photoelectrodes as well as the composition, morphology, and size of the catalysts. In recent years, significant and influential progress has been made in utilizing Si‐based photoelectrodes for PEC CO2 utilization. This review summarizes the latest research achievements in Si‐based PEC CO2 utilization, with a particular emphasis on the mechanistic understanding of CO2 reduction and fixation, which will inspire future developments in this field. There have been two pathways for PEC CO2 utilization to produce small molecule fuel and valuable chemicals, i. e. PEC CO2 reduction and PEC CO2 fixation. The key to achieving high efficiency, yield and selectivity of PEC CO2 utilization on Si‐based photoelectrodes lies in the rational design of the photoelectrode structure as well as the modulation of the composition, morphology, structure and size of the catalysts.