P and C co-modified g-C3N4/SiO2/ZnO Z-scheme based heterogeneous nanocomposite as a highly boosted visible-light-driven photocatalytic system

• Published in: Journal of alloys and compounds 2022-11, Vol.923, p.166392, Article 166392
• Main Authors: Tarighati Sareshkeh, Abdolreza, Bagheri Some-Saraee, Rahman, Rasoulifard, Mohammad Hossein, Seyed-Dorraji, Mir-Saeed, Hosseini, Seyyedeh Fatemeh
• Format: Article
• Language: English
• Subjects: Carbon; Carbon nitride; Catalytic activity; Chemical energy; Decontamination; Duckweed; Ecotoxicity level; Heterogeneous nanocomposite; Heterojunctions; Light irradiation; Methylene blue; Nanocomposites; Organic carbon; Oxidation; Photocatalysis; Photocatalytic activity; Pollutants; Silicon dioxide; White-LED light irradiation; Z-scheme heterojunction; Zinc oxide
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2022.166392

Catalytic-oriented applications of graphitic carbon nitride (g-C3N4 (GCN)) are excessively restricted by some intrinsic photoelectronic shortcomings. To address these issues, the amorphous phase of ZnO and SiO2, the electron-trapping role of SiO2, the high light-activity of pc-GCN, and the integrated Z-scheme heterojunction between ZnO and Phosphorous- and Carbon- co-modified GCN (pc-GCN) synergistically provided prominent features; these included the prolonged lifetime of photo-induced charges, the faster charge transportation, and the ultrafast transformation of light-to-chemical energy over the heterogeneous nanocomposite of pc-GCN/15 wt%-SiO2/5 wt%-ZnO (pc-GCN/15-SiO2/5-ZnO) that immensely outperformed pristine GCN under white-LED light irradiation (WLLI (λ ≥ 420 nm)). Therefore, Methylene Blue (MB) oxidation yield and Total Organic Carbon (TOC) removal were dramatically increased to 100 % and 96.8 % through the pseudo-second-order mechanism within 90 min under the optimum conditions, respectively. In addition to the expeditious eradication of organic pollutants, the photocatalytic activity of pc-GCN/15-SiO2/5-ZnO was about 10 times higher than that of GCN; the enhanced photocatalytic performances were facially resuscitated for long-lasting photocatalytic decontamination. More importantly, assessing Lemna minor's life corroborated the ecotoxicity level of the MB-depolluted effluent that was regulated by performing a post-treatment step. Overall, it is anticipated that these authentic accomplishments could highlight promising prospective for developing effectual two-step environmental remediation. [Display omitted] •The expeditious charge migration between amorphous and crystalline photocatalysts established.•Catalytic activity of pc-GCN enhanced by electron-trapping on SiO2 and Z-scheme mechanism by ZnO.•Photocatalytic eradication of MB barely improved by increasing generation of HO• at pH = 11.•The large enhanced catalytic performances of pc-GCN/15-SiO2/5-ZnO sustained after even 6th runs.•Two-step eco-remediation process led to close the toxicity of MB-depolluted effluent to water.