Comparisons of visible-light driven photocatalytic CO2 conversion performances over mesoporous CdSxSe1–x with different molecular compositions. Issue 52 (October 2021)

• Record Type: Journal Article
• Authors: Jung, Han Sol; Joo, Jinwhan; Lee, Kwangyeol; Kang, Yong Tae
• Is Part Of: Journal of CO₂ utilization. Issue 52(2021)
• Publication Date: 2021-10
• Subjects: Photocatalytic CO2 conversion -- Photocatalyst -- Compound semiconductor -- Mesoporous materials -- Hard templating; Carbon dioxide -- Periodicals; Carbon dioxide -- Environmental aspects -- Periodicals; Carbon dioxide mitigation -- Periodicals; Carbon dioxide; Carbon dioxide -- Environmental aspects; Carbon dioxide mitigation; Periodicals; 628.53205
• DOI: 10.1016/j.jcou.2021.101671
• Languages: English
• ISSNs: 2212-9820

Abstract

Graphical abstract: Highlights: Synthesis method for mesoporous CdSx Se1–x with different S/Se ratios is proposed. Materials exhibit excellent physical and optical properties for CO2 photoconversion. Visible light driven photocatalytic CO2 conversion tests were conducted. CdS0.5 Se0.5 achieved highest CO yield rate while CdSe achieved highest CH4 yield rate. As sulfur composition increased, CH4 yield rate gradually decreased. Abstract: This study presents a synthesis method for nanowire arrayed mesoporous CdSx Se1-x compounds with different S/Se molar ratios. Both ternary and binary compound semiconductors are synthesized by hard-templating using SBA-15 as a silica template. The synthesized mesoporous materials have high specific surface areas of approximately 65–100 m 2 g −1 and remarkable light absorption properties in the UV to visible light region (1.7–2.4 eV), and thus they are appropriate for the photo-conversion of CO2 into CO and CH4 . The results show that the compositions of CdSx Se1-x excellently agree with the compositions of the reactants. Moreover, the band gaps of the mesoporous CdSx Se1-x samples could be directly tuned by varying the composition of the reactants. It is concluded that mesoporous CdSe achieves the highest CH4 yield rate, i.e., 0.382 μmol gcat –1 h –1, and CdS0.5 Se0.5 achieves the highest CO yield rate (among all the samples synthesized), i.e., 5.633 μmol gcat –1 h –1 . Also, it is found that the CO2 photoconversion performance on mesoporous II-VI photocatalyst are highly affected by CO2 adsorption capacities and photo-generated charge separation.