Length Spinel MgAl2O4 nanospheres coupled with modified graphitic carbon nitride nanosheets as an efficient Z-scheme photocatalyst for photodegradation of organic contaminants

In this contribution, spinel MgAl2O4 nanospheres prepared by the combustion method were coupled with thermally-exfoliated g-C3N4 nanosheets (TE-GCN) through an efficient isoelectric point-assisted calcination technique. Physical characteristics of the synthesized nanocomposite were understudied utilizing the XRD, FT-IR, FE-SEM, TEM, BET-BJH, UV-Vis DRS, PL, and EIS analyses. This material was used as a novel nano-photocatalyst for degradation of reactive red 195 (RR195) industrial dye contaminant. Results revealed that, a successful synthesis of a heterojunction between the components of the nanocomposite was achieved. This exhibited an enormously improved electron-hole separation leading to an enhanced decontamination of the RR195 compared with those of the individual components of the prepared photocatalyst. Next the investigation of the influential reaction parameters suggested that, a complete degradation of the aforementioned contaminant could have been achieved in a solution of pH of 3.0 containing a photocatalyst dosage of 0.9 g/L after 70 min of duration under simulated sunlight illumination. Ultimately, a Z-scheme charge transfer mechanism for photodegradation of the RR195 over the TE-GCN@MgAl2O4 photocatalyst was proposed. Notably, this photocatalyst was highly stable and only a negligible reduction of about 6% in the photodegradation efficiency of it occurred after 5 consecutive catalytic reaction cycles.

Automated summary

Spinel MgAl2O4 nanospheres prepared by the combustion method were coupled with thermally-exfoliated g-C3N4 nanosheets (TE-GCN) through an efficient isoelectric point-assisted calcination technique. The synthesized nanocomposite exhibited improved electron-hole separation, leading to enhanced degradation of the RR195 dye contaminant. The optimal conditions for complete degradation were achieved at pH 3.0 with a photocatalyst dosage of 0.9 g/L and a duration of 70 minutes under simulated sunlight illumination. The TE-GCN@MgAl2O4 photocatalyst demonstrated high stability with only a negligible reduction in photodegradation efficiency after 5 consecutive catalytic reaction cycles.