Gradient heating-induced bi-phase synthesis of carbon quantum dots (CQDs) on graphene-coated carbon cloth for efficient photoelectrocatalysis. (30th August 2022)

• Record Type: Journal Article
• Authors: Ali, Mumtaz; Anjum, Aima Sameen; Bibi, Ayesha; Wageh, S.; Sun, Kyung Chul; Jeong, Sung Hoon
• Is Part Of: Carbon. Volume 196(2022)
• Page Start: 649
• Page End: 662
• Publication Date: 2022-08-30
• Subjects: Nitrogen-doped carbon quantum dots -- Temperature effect -- Dye degradation -- Photocatalyst and electrocatalyst -- Graphene modification -- Textile substrates -- Metal free catalyst; Carbon -- Periodicals; Carbone -- Périodiques; Koolstof; Toepassingen; Electronic journals; 546.681
• DOI: 10.1016/j.carbon.2022.05.040
• Languages: English
• ISSNs: 0008-6223

Abstract

Abstract: The challenges of secondary pollution and limited stability of metallic catalysts/quantum dots that are used for water treatment must be resolved in the emerging ecofriendly environmental systems. Conversely, carbon materials, specifically, conventional carbon quantum dots (C-CQDs) have emerged as an abundant, stable, and biocompatible alternative for visible-light-driven photocatalysts, that are used for water treatment. Despite these advantages, the fast charge recombination in quantum-confined systems, complex purification, and limited optoelectronic performance are bottlenecks in the practical application of C-CQDs. To address these issues, we proposed a scalable structural design of C-CQDs with enhanced photocatalytic properties. The synthesis process of CQDs was modified to yield a highly amorphous core carbon quantum dots (AC-CQDs), which was controlled by varying the synthesis temperature. The low initial temperature during the synthesis of the AC-CQDs yields an amorphous core, which provides a high electrical resistance; hence, the indirect recombination occurring through core conductivity is significantly suppressed. To ensure scalable synthesis and stability, AC-CQDs were directly grown on reduced graphene oxide, which was coated on a carbon fabric to fabricate a textile-structured electrode. Efficient charge separation in the proposed catalyst electrode structure offers significantly improved photoelectrocatalytic activity, i.e., 100% effluent dye degradation in 25 min. Graphical abstract: Image 1 Highlights: Scalable structural design of CQDs with enhanced photocatalytic and diverse optical properties is proposed. Bi-phase (amorphous and crystalline domains) were formed by incorporating gradient heating in the synthesis process. Achieved heterogeneous growth of CQDs through a one-step process, which provides a strong interface between CQDs and rGO. AD@rGO electrode achieved 100% photoelectrocatalytic effluent dye degradation in 25 min.