{"title":"Breaking the Symmetry of Sulfur Defect State via Atomic Substitution for Enhanced CO2 Photoreduction","authors":"Yingxin Ma, Haolan Tao, Xuyun Guo, Peinuo Yang, Dan Xing, Valeria Nicolosi, Yu Zhang, Cheng Lian, Bocheng Qiu","doi":"10.1039/d4ta06622g","DOIUrl":null,"url":null,"abstract":"Conventional sulfur vacancy, characterized by a symmetric coordination of metal cations (M1-SV-M1), typically serves as a catalytic site for CO2 chemisorption. However, the symmetric SV site, with a uniform charge distribution across adjacent metal sites, enables sluggish electron transfer kinetics for CO2 activation and dissociation, as well as a low defect-band center that renders photoexcited electrons less energetic. Herein, we introduced Cu dopant into SV-rich SnS2 nanosheets (Cu-SnS2-SV) to construct the asymmetric Cu-SV-Sn sites, which effectively steer CO2 photoreduction into CO with a production rate of 48.6 μmol g-1 h-1 in the absence of photosensitizer and scavenger, 18-fold higher than SnS2-SV with symmetric Sn-SV-Sn sites. The experimental investigations combined with theoretical simulations reveal that asymmetric Cu-SV-Sn structure, compared with symmetric Sn-SV-Sn structure, allows an upshift of the defect-band center, which significantly mitigates the energy loss associated with the electron relaxation from conduction band to defect band. Moreover, the advantages of the Cu-SV-Sn sites over the Sn-SV-Sn sites are demonstrated not only by the increased Sn-S covalency, which facilitates electron transfer from catalysts to adsorbates, but also by the improved ability to stabilize the COOH* intermediates, which lowers the activation energy barrier of the rate-determining step.","PeriodicalId":82,"journal":{"name":"Journal of Materials Chemistry A","volume":null,"pages":null},"PeriodicalIF":10.7000,"publicationDate":"2024-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Materials Chemistry A","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1039/d4ta06622g","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Conventional sulfur vacancy, characterized by a symmetric coordination of metal cations (M1-SV-M1), typically serves as a catalytic site for CO2 chemisorption. However, the symmetric SV site, with a uniform charge distribution across adjacent metal sites, enables sluggish electron transfer kinetics for CO2 activation and dissociation, as well as a low defect-band center that renders photoexcited electrons less energetic. Herein, we introduced Cu dopant into SV-rich SnS2 nanosheets (Cu-SnS2-SV) to construct the asymmetric Cu-SV-Sn sites, which effectively steer CO2 photoreduction into CO with a production rate of 48.6 μmol g-1 h-1 in the absence of photosensitizer and scavenger, 18-fold higher than SnS2-SV with symmetric Sn-SV-Sn sites. The experimental investigations combined with theoretical simulations reveal that asymmetric Cu-SV-Sn structure, compared with symmetric Sn-SV-Sn structure, allows an upshift of the defect-band center, which significantly mitigates the energy loss associated with the electron relaxation from conduction band to defect band. Moreover, the advantages of the Cu-SV-Sn sites over the Sn-SV-Sn sites are demonstrated not only by the increased Sn-S covalency, which facilitates electron transfer from catalysts to adsorbates, but also by the improved ability to stabilize the COOH* intermediates, which lowers the activation energy barrier of the rate-determining step.
期刊介绍:
The Journal of Materials Chemistry A, B & C covers a wide range of high-quality studies in the field of materials chemistry, with each section focusing on specific applications of the materials studied. Journal of Materials Chemistry A emphasizes applications in energy and sustainability, including topics such as artificial photosynthesis, batteries, and fuel cells. Journal of Materials Chemistry B focuses on applications in biology and medicine, while Journal of Materials Chemistry C covers applications in optical, magnetic, and electronic devices. Example topic areas within the scope of Journal of Materials Chemistry A include catalysis, green/sustainable materials, sensors, and water treatment, among others.