Critical roles of Co‐doped g‐C₃N₄/Bi₂WO₆ in photocatalytic removal of organic pollutants and treating oil field wastewater in electrocatalysis‐microbial fuel cells

Abstract

BACKGROUNDPhotocatalysts with Z‐type heterojunction structures for organic pollutant removal are prospective in environmental advanced oxidation processes. Introducing single metal atom to the heterojunction can further improve the synergistic activity of photocatalysts, so we doped Co single metal atom in g‐C3N4/Bi2WO6 Z‐type heterojunction.RESULTSFor this aim, a simple calcination and hydrothermal method was used to dope single atom Co on top of the Z‐type 10 wt% g‐C3N4/Bi2WO6 heterojunctions which we had tested previously. The optimal Co doping was determined at 0.2 wt% Co/10 wt% g‐C3N4‐Bi2WO6, that it most efficiently degraded (100 mg/L) RhB under visible light irradiation (99.7% in 30 min, kinetic rate constant 0.182 min −1). This single‐atom doped catalysts (Co/g‐C3N4/Bi2WO6) should be most favorably used in treating practical wastewater in EC (electro‐chemical)‐MFC (microbial fuel cell) system. Its remarkable performance was recorded (96% COD removal and 92.8% TOC removal).CONCLUSIONThe reactive oxidizing species include h+, 1O2, ·O2−, e−, and OH, they act together leading to the rapid degradation of pollutants. The developed Co‐doped ternary catalyst has promising application prospects in pollution control in real world wastewater treatment. © 2023 Society of Chemical Industry.

Rational optimization of 2D Bi2MoO6 nanopiece@2D g‐C3N4 nanoflake composite for boosting photocatalytic performance of hydrogen evolution rate and organic dye removal

“…However, when 1, 4‐benzoquinone, 1 mmol L −1 (BQ) was added, the degradation rate of RhB was significantly reduced to only 53%, and the degradation rate constant was only 0.007 min −1 , indicating that O 2 − played an important role in the oxidation process of RhB. Therefore, the active species capture experiments indicated that O 2 − and • OH were the two main active species in the RhB degradation process 62‐73 …”

“…Therefore, the active species capture experiments indicated that O 2 − and • OH were the two main active species in the RhB degradation process. [62][63][64][65][66][67][68][69][70][71][72][73] Based on the above results, a schematic diagram of the photocatalytic degradation mechanism of RhB under visible-light irradiation by Bi 2 MoO 6 nanopiece@g-C 3 N 4 nanoflake composite shown in Fig. 10 was proposed.…”