Dual Functional S-Doped g-C3N4 Pinhole Porous Nanosheets for Selective Fluorescence Sensing of Ag+ and Visible-Light Photocatalysis of Dyes

Abstract

This study explores the facile, template-free synthesis of S-doped g-C3N4 pinhole nanosheets (SCNPNS) with porous structure for fluorescence sensing of Ag+ ions and visible-light photocatalysis of dyes. As-synthesized SCNPNS samples were characterized by various analytical tools such as XRD, FT-IR, TEM, BET, XPS, and UV–vis spectroscopy. At optimal conditions, the detection linear range for Ag+ was found to be from 0 to 1000 nM, showing the limit of detection (LOD) of 57 nM. The SCNPNS exhibited highly sensitive and selective detection of Ag+ due to a significant fluorescence quenching via photo-induced electron transfer through Ag+–SCNPNS complex. Moreover, the SCNPNS exhibited 90% degradation for cationic methylene blue (MB) dye within 180 min under visible light. The enhanced photocatalytic activity of the SCNPNS was attributed to its negative zeta potential for electrostatic interaction with cationic dyes, and the pinhole porous structure can provide more active sites which can induce faster transport of the charge carrier over the surface. Our SCNPNS is proposed as an environmental safety tool due to several advantages, such as low cost, facile preparation, selective recognition of Ag+ ions, and efficient photocatalytic degradation of cationic dyes under visible light.

Conjugated Electron Donor–Acceptor Hybrid Polymeric Carbon Nitride as a Photocatalyst for CO2 Reduction

“…Numerous negative properties, such as a small surface area, high charge recombination rate, and small light absorption capability hinder further exploitation of the parental PCN and predict a negative photocatalytic performance [18,19]. Therefore, many scientists have explored a variety of fundamental approaches to modifying PCN networks, e.g., heterojunctions [20], noble metal deposition [21], doping [22,23], and morphological control [24,25], that have significantly improved its photocatalytic activity. Inspired by these developments, co-polymerization has come forth as a new prominent technique to accomplish this by using new energized organic conjugated co-monomers embedded within the framework of PCN to enhance its photocatalytic properties.…”

A review on recent advances in selective and sensitive detection of heavy toxic metal ions in water using g-C3N4-based heterostructured composites

“…27 shows the fluorescent features of SCNPNS for 15 different biologically and environmentally-relevant metal ions (including Co 2+ , In 3+ , Ca 2+ , Cd 2+ , Fe 3+ , Cu 2+ , Fe 2+ , Blank, Ag + , K + , La 3+ , Mn 2+ , Na + , Hg 2+ , Pb 2+ , and Zn 2+ ) at pH 7. 266 After the addition of these heavy metal ions (20 mM), the pictorial image of the SCNPNS solution was recorded under UV light (365 nm). An aqueous solution of SCNPNS with Ag + displayed significant fluorescence quenching, but there is no prominent fluorescence quenching observed for other metal ions (Fig.…”

“…27(a)). 266 The relative PL responses of blank SCNPNS and the SCNPNS after quenching with metal ions are shown in Fig. 27(b).…”

An Integrative Approach to Study Bacterial Enzymatic Degradation of Toxic Dyes

“…Removal and decolorization of brilliant red X-3B have been successfully done by combining photocatalytic and biocatalysis (Zhang et al, 2017). It was reported that nanosheets complex with silver cations led to the 90% decolorization of methyl blue via photocatalytic activity (Kadam et al, 2019). Using nanocomposites as photocatalysts also have shown positive results in decolorizing titan yellow and methyl orange dyes (Kumar et al, 2020).…”