Self-standing CdS/TiO2 Janus nanofiberous membrane: COD removal, antibacterial activity and photocatalytic degradation of organic pollutants

• Published in: Journal of environmental chemical engineering 2024-06, Vol.12 (3), p.112521, Article 112521
• Main Authors: Pandeya, Shiva, Ding, Rui, Ma, Yufei, Han, Xuling, Gui, Meixing, Mulmi, Purnima, Panthi, Khim Prasad, Neupane, Bhanu Bhakta, Pant, Hem Raj, Li, Ziliang, Joshi, Mahesh Kumar
• Format: Article
• Language: English
• Subjects: Chemical oxygen demand; Electrospinning; Organic pollutants; Photocatalysis; Reusability
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2024.112521

The self-standing TiO2 nanofiber-based heterojunction with excellent visible-light-driven photocatalytic activity, antimicrobial activity, and reusability holds great importance in water and airborne pollutant management. Herein, a series of splendid flexible CdS/TiO2 (CdS/TZ) nanofibrous membranes (NFMs) were fabricated by facile post-electrospinning treatment. The self-standing TiO2 NFM was first prepared via the electrospinning technique followed by controlled calcination, and then the CdS nanoparticles (NPs) were grown by the successive ionic layer adsorption and reaction (SILAR) method. The careful deposition of CdS NPs preserved the self-standing properties of the TiO2 membrane. The amount of CdS NPs in the CdS/TiO2 membrane was tailored by varying the SILAR cycles. The CdS/TiO2 heterojunction demonstrated superior antimicrobial efficacy against both Gram-positive and Gram-negative bacteria. Additionally, it enhanced the photocatalytic degradation of the methyl orange and effectively removed oxidizable impurities from pharmaceutical effluent while maintaining good recycling capacity. The photocatalytic degradation of methyl orange obeyed the pseudo-first-order reaction dynamics model and showed a strong influence of the CdS amount on the degradation. The maximum degradation rate for methyl orange dye using the CdS/TiO2 Janus membrane was 0.057 min−1, which was 3.5 times that of the TiO2 membrane. The degradation efficiency of CdS/ TiO2 was found to be up to 96.8% in 60 minutes and showed excellent photocatalytic activity in five consecutive cycles. The chemical oxygen demand (COD) removal efficiency for the TiO2 membrane was 74.16, which was increased to 91.66% for the CdS/TiO2 membrane. This study provides insight into developing highly efficient Janus inorganic nanofiber with superior structural integrity for waste water treatment and environmental remediation. [Display omitted] •CdS/TiO2 heterojunction formed by a simple deposition of CdS NPs onto TiO2 nanofibers via the SILAR method.•Janus function such as COD removal, antibacterial activity, photocatalytic degradation of organic pollutants was achieved.•The CdS/TiO2 photocatalyst shows high potential for recycling.