Green Synthesis of Carbon Nitride‐Based Conjugated Copolymer for Efficient Photocatalytic Degradation of Tetracycline

Abstract

Upcycling waste plastics into advanced semiconductor photocatalysts provides a new strategy to reasonably and economically solve the huge amount of waste plastics, which remains challenging. Herein, a carbon nitride-based donor-acceptor (D-A) conjugated copolymer by copolymerization of dicyandiamide and terephthalic acid from discarded polyethylene terephthalate (PET) using Zn(OH) 2 as catalyst and template at 360-440 °C is synthesized. The morphology and structure of the conjugated copolymer are well regulated by the calcination temperature. The resultant conjugated copolymer exhibits merits of high light absorption and low electron-hole recombination probability. Consequently, it works excellently in the persulfate-based advanced oxidation process for visible light-driven photocatalytic degradation of tetracycline. The kinetic constant (3.4 × 10 −2 min −1 ) is 40.5 and 2.3 times that of the conjugated copolymer system and persulfate system, respectively. Furthermore, the reactive species (including •OH, SO 4 •− , •O 2 − , 1 O 2 , and h + ) and degradation intermediates of tetracycline are analyzed to expound its degradation process. This work not only pioneers design guidelines on upcycling of waste plastics in a sustainable manner, but also provides a facile strategy to synthesize carbon nitride-based D-A conjugated copolymers for the efficient activation of persulfate-based advanced oxidation process in wastewater treatment.

Ultratrace Aromatic Anhydride Dopant as Intermediate Island to Promote Charge Transfer of Graphitic Carbon Nitride for Enhancing the Photocatalytic Degradation of Rhodamine B

“…The broad peaks at 3000–3500 cm –1 are attributable to the amino group (–NH x ) and surface water molecule . The CO stretching vibration of the amide bond and N–H bending vibration are displayed at 1683 and 1543 cm –1 , respectively. The characteristic double peaks of the C–C stretching vibration of the pyridine ring are displayed at 1573 and 1408 cm –1 , and the CN absorption peaks at 1573 and 1408 cm –1 confirm further the presence of the pyridine ring .…”

Fabrication of a Ternary Nanocomposite g-C3N4/Cu@CdS with Superior Charge Separation for Removal of Organic Pollutants and Bacterial Disinfection from Wastewater under Sunlight Illumination

“…Graphitic carbon nitride(g-C 3 N 4 ), a polymeric compound comprised of carbon, nitrogen, graphene and a minor amount of hydrogen content, has been introduced as a metal-free photo-catalyst that exhibits solar-driven applications [19] and water purification applications [20,21]. The use of this organic semiconductor is advantageous because of its economic feasibility, ease of availability, relatively high stability, and most important intrinsic visible light response [22][23][24][25]. Tian et al reported different dimensional structures of g-C 3 N 4 photo-catalyst.…”