Photothermal-boosted S-scheme heterojunction of α-Fe2O3@NiOx for high-selective reduction of CO2 to CO

• Published in: Applied surface science 2024-10, Vol.671, p.160747, Article 160747
• Main Authors: Liu, Xiao, Kaihui, Bai, Nie, Yuhang, Wang, Xusheng, Pei, Lang
• Format: Article
• Language: English
• Subjects: CO2 reduction; Photothermal catalysis; S-scheme heterojunction; α-Fe2O3
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2024.160747

[Display omitted] •A novel S-type heterojunction photothermal catalyst consisting of α-Fe2O3 and NiOx was developed.•Thermal-assisted photocatalytic mechanism CO2-to-CO was verified.•Optimal α-Fe2O3@NiOx heterojunction exhibited a CO yield rate of 199.3 μmol∙g−1·h−1 with a selectivity nearly 100 %. Self-heating photothermal catalysis, combining light promotion and thermal activation, offers unique advantages for CO2 conversion. The meticulous design of active sites and light-absorbing materials is crucial for high-performance photothermal catalysts. Herein, a S-Scheme heterostructure composed of NiOx subunits with abundant oxygen vacancies (Vo) bonded with α-Fe2O3 nanoplatelets has been fabricated for solar-driven photothermal catalytic CO2 reduction. Under continuous full-spectrum light irradiation (0.3 W·cm−2), the α-Fe2O3@NiOx hybrids exhibited a CO yield rate of 199.3 μmol∙g−1·h−1 in a gas–solid reaction models with near-unity selectivity. Additionally, the apparent quantum yield for CO production at 420 nm reaches 1.56 %. The prominent activity is attributed to three key factors: (1) The Vo-rich NiOx facilitates the accumulation of photogenerated electrons and activation of chemisorbed CO2. (2) The implemented S-Scheme heterostructures boost interfacial charge-transfer and provide spatially separated catalytic sites for efficient overall CO2 reduction. (3) The substantial photothermal effect of NiOx, which arises from nonradiative exciton recombination, induces local heating of the catalyst, thereby enhancing reaction kinetics. This work provides valuable insights into the utilization of a photothermal-photocatalytic S-Scheme heterojunction system for the photothermal catalytic CO2 reduction.