Boosted insights of novel accordion-like (2D/2D) hybrid photocatalyst for the removal of cationic dyes: Mechanistic and degradation pathways

• Published in: Journal of environmental management 2020-11, Vol.273, p.111125-111125, Article 111125
• Main Authors: Vigneshwaran, Sivakumar, Karthikeyan, Perumal, Park, Chang Min, Meenakshi, Sankaran
• Format: Article
• Language: English
• Subjects: 2D/2D hybrid photocatalyst; Cationic-dyes; MXene; Oxidative pathway; Photo‒degradation
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2020.111125

In the present work, a novel (2D/2D) accordion like CS@g‒C3N4/MX hybrid composite was prepared through one-pot hydro-thermal synthesis method and utilized as a catalyst for the degradation of organic persistent dyes such as methylene blue (MB) and rhodamine B (RhB). Because the removal of such organic compounds is a major dispute in environmental aspects. In this study, the bio-assisted g‒C3N4/MX nanosheets was utilized for the removal of organic dyes from aqueous solution under visible light irradiation, respectively. The CS@g-C3N4/MX photocatalyst showed high catalytic activity based on ~99% and ~98.5% degradation of MB and RhB within 60 and 40 min using visible light irradiation. This outcome could have resulted in greater catalytic enactment towards the degradation of other persistent pollutants with enhanced light absorption property and it can efficiently suppress photo-generated charge recombination, thus improving the interfacial charge transfer rate. The OH radical was being effective oxidative species involved in the CS@g-C3N4/MX system for the degradation of organic contaminants. Furthermore, CS@g-C3N4/MX showed excellent photo-stability over five consecutive cycles for the degradation of organic dyes with negligible loss of photocatalytic activity. Finally, the purposed catalytic mechanisms and degradation pathways of MB and RhB were systematically discussed in detail based on experimental results. Thus, the organics which oxidized into ring-opened compounds such as ethoxyethane, butadiene etc., to non-toxic products like H2O, CO2 and some mineral salts. [Display omitted] •A novel accordion-like 2D/2D g-C3N4/MX promotes charge transfer and separation efficiency of photo generated e--h+ carriers.•2D/2D heterojunction at interfacial charge transfer abilities of p-n junction mode.•Insight active sites to promote photocatalytic performance of CS@g-C3N4/MX photocatalyst.•Interaction at the hetero-interfaces between 2D/2D heterojunction.•This work reveals detailed pathways and generation of active species on degradation of dyes