Dual photoluminescence centers from inorganic-salt-functionalized carbon dots for ratiometric pH sensing

Abstract

A controlled and effective strategy is offered for synthesizing carbon dots (CDs) with dual photoluminescence peaks and reliable fluorescence ratiometric pH sensing.

Carbon‐Dot‐Based Heterojunction for Engineering Band‐Edge Position and Photocatalytic Performance

“…Besides the shift of main peak from PO(OH) contributions, the CP signal peak resulting from DAP modification disappears in XPS spectrum of CDs@Ag 3 PO 4 . The CD surface with CP bonds can be possibly covered by Ag 3 PO 4 , relieving their signals in XPS spectra . Accordingly, all of above results have demonstrated the heterostructure formation of Ag 3 PO 4 and CDs.…”

“…For comparision, only Ag 3 PO 4 sample was also prepared by directly reacting AgNO 3 with DAP under the same conditions. DAP‐modified CDs were from our previous work and possessed dual photoluminescence color (Figure S1, Supporting Information) . These CDs contain abundant phosphate‐related groups on their surface .…”

“…DAP‐modified CDs were from our previous work and possessed dual photoluminescence color (Figure S1, Supporting Information) . These CDs contain abundant phosphate‐related groups on their surface . Consequently, the heterogeneous nucleation of Ag 3 PO 4 nanocrystals on the CDs is remarkably promoted while the homogeneous nucleation of Ag 3 PO 4 is suppressed greatly, giving rise to the formation of CDs@Ag 3 PO 4 .…”

“…[21,22] These CDs contain abundant phosphate-related groups on their surface. [22] Consequently, the heterogeneous nucleation of Ag 3 PO 4 nanocrystals on the CDs is remarkably promoted while the homogeneous nucleation of Ag 3 PO 4 is suppressed greatly, [18] giving rise to the formation of CDs@Ag 3 PO 4 . Phenomenally, the reaction of the AgNO 3 with DAP-modified CDs is much slower than that with DAP solution.…”

“…Preparation of DAP‐Modified CDs : Preparation of DAP‐modified CDs was based on the previous work . The CD solution was first prepared from coal through a selective oxidation process as described Subsequently, 100 mg of DAP was added in 10 mL of CD solution and mixed with 10 mL absolute ethanol.…”