Advanced activation of persulfate by polymeric g-C3N4 based photocatalysts for environmental remediation: A review

Abstract

Photocatalytic materials for photocatalysis is recently proposed as a promising strategy to address environmental remediation. Metal-free graphitic carbon nitride (g-C 3 N 4 ), is an emerging photocatalyst in sulfate radical based advanced oxidation processes. The solar-driven electronic excitations in g-C 3 N 4 are capable of peroxo (O-O) bond dissociation in peroxymonosulfate/peroxydisulfate (PMS/PDS) and oxidants to generate reactive free radicals, namely SO 4•− and OH • in addition to O 2 •− radical. The synergistic mechanism of g-C 3 N 4 mediated PMS/ PDS photocatalytic activation, could ensure the generation of OH • radicals to overcome the low reductive potential of g-C 3 N 4 and fastens the degradation reaction rate. This article reviews recent work on heterojunction formation (type-II heterojunction and direct Z-scheme) to achieve the bandgap for extended visible light absorption and improved charge carrier separation for efficient photocatalytic efficiency. Focus is placed on the fundamental mechanistic routes followed for PMS/PDS photocatalytic activation over g-C 3 N 4 -based photocatalysts. A particular emphasis is given to the factors influencing the PMS/PDS photocatalytic activation mechanism and the contribution of SO 4 •− and OH • radicals that are not thoroughly investigated and require further studies. Concluding perspectives on the challenges and opportunities to design highly efficient persulfateactivated g-C 3 N 4 based photocatalysts toward environmental remediation are also intensively highlighted.

TiO2@MOF Photocatalyst for the Synergetic Oxidation of Microcystin-LR and Reduction of Cr(VI) in Aqueous Media

“…Therefore, it is urgent that develop a promising method to remove them more efficiently be developed. In general, methods for their removal include separation, adsorption, and photodegradation [11][12][13], in which photocatalytic detoxification is commonly identified as a sustainable strategy.…”

Ultrathin 2D/2D ZnIn2S4/g‐C3N4 Nanosheet Heterojunction with Atomic‐Level Intimate Interface for Photocatalytic Hydrogen Evolution under Visible Light

“…[22][23][24] Graphite carbon nitride (g-C 3 N 4 ) is an attractive nonmetallic conjugated polymer semiconductor, which has been extensively applied in photocatalytic water splitting because of its attractive electronic structure, excellent thermal and chemical stability, unique 2D layered structure, suitable band gap, low toxicity, etc. [25][26][27] However, the actual application of the original g-C 3 N 4 still suffers from the limitations of underutilization of visible light, lacking of catalytic active sites, hydrophobic surface, low carrier mobility, and rapid recombination of photoinduced carriers. [28,29] For addressing these challenges, various strategies have been adopted so as to improve the photocatalytic performance of the original g-C 3 N 4 , such as nanostructure design, [30][31][32] doping of metallic and nonmetallic elements, [33][34][35][36] construction of heterojunctions, [37][38][39][40] copolymerization, [41][42][43] defect engineering, and dye sensitization.…”

La2Sn2O7/g-C3N4 nanocomposites: Rapid and green sonochemical fabrication and photo-degradation performance for removal of dye contaminations

“…Graphitic carbon nitride (g-C 3 N 4 ) polymeric component was selected to the formation of La 2 Sn 2 O 7 /CN nanocomposite because of suitable energy gap (2.7 eV), high surface area and cheap synthesis route as well as finally, advanced photocatalytic activity [34] . Numerous researches illustrate that using g-C 3 N 4 has a favorable impact on photocatalytic efficiency [35] , [36] . In this work, La 2 Sn 2 O 7 / g-C 3 N 4 nanocomposites were fabricated via green and rapid ultrasonic technique in presence of broccoli extract natural surfactant.…”