Plant-Based Phytochemicals for Synthesis of Z‑Scheme In2O3/CdS Heterostructures: DFT Analysis and Photocatalytic CO2 Reduction to HCOOH and CO

• Published in: Langmuir Vol. 40; no. 26; pp. 13538 - 13549
• Main Authors: Gawal, Pramod Madhukar, Golder, Animes Kumar
• Format: Journal Article
• Language: English
• Published: American Chemical Society 02.07.2024
• ISSN: 0743-7463; 1520-5827; 1520-5827
• DOI: 10.1021/acs.langmuir.4c01015

Photocatalytic CO2 reduction shows potential for mitigating industrial emissions. Z-scheme In2O3/CdS­(bio) heterostructures (25 nm, 217.0 m2 g–1 surface area) with a more negative conduction band synthesized using phytochemicals present in Aegle marmelos with short microwave irradiation inhibit CdS­(bio) photocorrosion forming SO4 2–. In2O3/CdS­(bio) increased the photocurrent density (0.82 μA cm–2) and CO2 adsorption (0.431 mmol g–1) significantly compared to CdS­(bio) and In2O3(bio) NPs. Heterostructures increased decay time and reduced PL intensity by 46.28 and 61.80% over those of CdS­(bio) and In2O3(bio) NPs. Density functional theory (DFT)-optimized geometry, band structure analysis, and density of states (DOS) studies indicate that the DOS of CdS is modified with In2O3 incorporation, enhancing charge separation. Optimal 0.4In2O3/CdS­(bio) heterostructures exhibit remarkable CO2 conversion to HCOOH/CO production of 514.4/162 μmol g–1 h–1 (AQY 4.44/2.45%), surpassing CdS­(bio) and In2O3(bio) by 9 and 6.5 times, and retain their morphological and structural stability. This study provides valuable insight for developing bio-based CdS heterostructures for photocatalytic CO2 reduction.