Heterojunction engineered MWCNT/Ag[formula omitted] via organic acid and its natural light-assisted photocatalytic efficiency

Abstract

Compositing photoactive, but unstable semiconductors with low dimensional carbon-based materials and modulating the hetero junction between them can assure more efficient and stable systems for the remediation of severe pollutants. The current study has given emphasis to understand the role of sulfonic acid in making a compact heterojunction between AP and MWCNTs, considering the effective delocalization of carriers and the direct relationship with the photoactivity. The significant reduction in the band gap of AP from 2.320 to 2.0516ev after the introduction of MWCNTs unmistakably confirmed the compatibility between the composite moieties. The intensity of the photoluminescence peak observed at an emission wavelength of 350nm for pure AP was found to be minimized in the composite, which confirms the effective charge delocalization from AP to the conductive MWCNTs. The closest bond distance was observed in the range of 2.3 to 2.5Å between an O atom of Ag3PO4 and a C atom of CNT, which explains the tight contact between the species. The photoactivity studies unambiguously confirmed the potential of the organic acid at the composite interface as it could accomplish 99% dye degradation within a span of 8min, whilst the system without the organic acid exhibited complete degradation within a span of 60min. The p-XRD analysis of the catalyst recovered from the reaction mixture revealed its high stability.