Photoredox Coupling of CO2 Reduction with Benzyl Alcohol Oxidation over Ternary Metal Chalcogenides (ZnmIn2S3+m, m = 1-5) with Regulable Products Selectivity

Zisheng Du; Kexin Gong; Zhiruo Yu; Yang Yang; Peixian Wang; Xiuzhen Zheng; Zhongliao Wang; Sujuan Zhang; Shifu Chen; Sugang Meng

doi:10.3390/molecules28186553

Photoredox Coupling of CO₂ Reduction with Benzyl Alcohol Oxidation over Ternary Metal Chalcogenides (Zn_mIn₂S_3+m, m = 1-5) with Regulable Products Selectivity

Molecules. 2023 Sep 10;28(18):6553. doi: 10.3390/molecules28186553.

Authors

Zisheng Du¹, Kexin Gong², Zhiruo Yu¹, Yang Yang^{1

2

3}, Peixian Wang⁴, Xiuzhen Zheng¹, Zhongliao Wang¹, Sujuan Zhang¹, Shifu Chen^{1

2}, Sugang Meng^{1

2

4}

Affiliations

¹ Key Laboratory of Green and Precise Synthetic Chemistry and Applications, Ministry of Education, College of Chemistry and Materials Science, Huaibei Normal University, Huaibei 235000, China.
² Key Laboratory of Pollutant Sensitive Materials and Environmental Remediation, Key Laboratory of Clean Energy and Green Circulation, Huaibei Normal University, Huaibei 235000, China.
³ Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan University, Shanghai 200438, China.
⁴ State Key Laboratory Incubation Base for Green Processing of Chemical Engineering, School of Chemistry and Chemical Engineering, Shihezi 832003, China.

Abstract

Integrating photocatalytic CO₂ reduction with selective benzyl alcohol (BA) oxidation in one photoredox reaction system is a promising way for the simultaneous utilization of photogenerated electrons and holes. Herein, Zn_mIn₂S_3+m (m = 1-5) semiconductors (ZnIn₂S₄, Zn₂In₂S₅, Zn₃In₂S₆, Zn₄In₂S₇, and Zn₅In₂S₈) with various composition faults were synthesized via a simple hydrothermal method and used for effective selective dehydrocoupling of benzyl alcohol into high-value C-C coupling products and reduction of CO₂ into syngas under visible light. The absorption edge of Zn_mIn₂S_3+m samples shifted to shorter wavelengths as the atomic ratio of Zn/In was increased. The conduction band and valence band position can be adjusted by changing the Zn/In ratio, resulting in controllable photoredox ability for selective BA oxidation and CO₂ reduction. For example, the selectivity of benzaldehyde (BAD) product was reduced from 76% (ZnIn₂S₄, ZIS1) to 27% (Zn₄In₂S₇, ZIS4), while the selectivity of hydrobenzoin (HB) was increased from 22% to 56%. Additionally, the H₂ formation rate on ZIS1 (1.6 mmol/g/h) was 1.6 times higher than that of ZIS4 (1.0 mmol/g/h), and the CO formation rate on ZIS4 (0.32 mmol/g/h) was three times higher than that of ZIS1 (0.13 mmol/g/h), demonstrating that syngas with different H₂/CO ratios can be obtained by controlling the Zn/In ratio in Zn_mIn₂S_3+m. This study provides new insights into unveiling the relationship of structure-property of Zn_mIn₂S_3+m layered crystals, which are valuable for implementation in a wide range of environment and energy applications.

Keywords: CO2 reduction; ZnIn sulfide; benzyl alcohol oxidation; photocatalytic; syngas.

Abstract

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