Performance analysis of rGO-bridged g-C3N4/ZnV2O6 S-scheme heterojunction for CO2 photoreduction with H2O in an externally reflected photoreactor

• Published in: Journal of alloys and compounds Vol. 968; p. 171833
• Main Authors: Bafaqeer, Abdullah, Tahir, Muhammad, Amin, Nor Aishah Saidina, Ummer, Aniz Chennampilly, Thabit, Hammam Abdurabu, Dhamodharan, Duraisami, Ahmed, Shakeel, Kumar, Naveen
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.12.2023
• Subjects: CO2 reduction; Externally reflected photoreactor; g-C3N4/rGO/ZnV2O6 nanocomposite; Performance analysis; S-scheme heterojunction; Solar fuels; Solar fuels; Performance analysis; CO2 reduction; Externally reflected photoreactor; S-scheme heterojunction; g-C3N4/rGO/ZnV2O6 nanocomposite
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2023.171833

The photocatalytic conversion of CO2 with H2O over rGO-bridged g-C3N4/ZnV2O6 S-scheme heterojunction using an externally reflected photoreactor has been investigated. The structure and properties of photocatalysts, prepared via the one-pot solvothermal method, were characterized by XRD, RAMAN, FESEM, EDX, HRTEM, UV–vis and PL spectrophotometry. The 4 % rGO-bridged g-C3N4/ZnV2O6 (1:1) nanocomposite registered the highest CH3OH yield. The maximum yield of CH3OH over 4 % rGO-bridged g-C3N4/ZnV2O6 (1:1) nanocomposite was 6246.1 μmol/g-cat; 1.34 and 1.51 folds higher than g-C3N4/ZnV2O6 (1:1) and ZnV2O6 photocatalysts, respectively. Significant enhancement in quantum efficiency of an externally reflected photoreactor over 4 % rGO-bridged g-C3N4/ZnV2O6 (1:1) nanocomposite was observed compared to the slurry photoreactor. This is obviously because of the greater mobility of charges with hindered recombination rate and higher photonic efficiency. The stability of 4 % rGO-bridged g-C3N4/ZnV2O6 (1:1) nanocomposite was partially reduced after several cyclic runs. It is believed that the photocatalyst consisting of three components has demonstrated improved photocatalytic activity through a S-scheme mechanism, utilizing rGO as an electron mediator to enhance the overall performance of the S-scheme heterojunction. [Display omitted] •S-scheme rGO modified g-C3N4/ZnV2O6 nanocomposite fabricated for efficient photocatalytic CO2 conversion to methanol.•rGO function as solid state electron mediator to get higher yield.•Externally reflected photoreactor found efficient and selective for CO2 conversion into CH3OH.•Efficiency of g-C3N4/rGO/ZnV2O6 was 1.6 time of ZnV2O6 and 6.4-fold of g-C3N4.•rGO modified g-C3N4/ZnV2O6 nanocomposite exhibited higher stability in cyclic runs because of good interface interaction.