Developing controllable mesoporous CoTiO3/C3N4 heterostructures for enhanced photocatalytic performances

Excellent charge carrier kinetics and high light absorption capability are key factors in increasing photocatalytic efficiency. Here, novel mesoporous CoTiO3/g-C3N4 heterostructures at varying CoTiO3 percentages were synthesized utilizing an easy soft and hard template approach for the degradation of acridine orange (AO) under visible light exposure. The TEM images exhibited irregular nanocrystals containing stacked g-C3N4 layers with crimped nanosheets, and spherical CoTiO3 NPs (10 nm) were uniformly distributed throughout the g-C3N4 layers. The results indicated that the mesoporous 3%CoTiO3/g-C3N4 heterostructure exhibited the highest degradation of AO dye (100%) within 60 min compared to g-C3N4 (10%) and CoTiO3 (18%). Furthermore, the 3% CoTiO3/g-C3N4 heterostructure had a better degradation rate, approximately 10.75- and 6.93-fold larger than those of g-C3N4 and CoTiO3 NPs, respectively. The enhanced mesoporous CoTiO3/g-C3N4 exhibited effective photoinduced carrier separation, a widened light harvesting range, and synergistic effects. Additionally, the 3% CoTiO3/g-C3N4 heterostructure revealed superior photocatalytic stability in AO dye recycling degradation for long-life regeneration. A direct Z-scheme mechanism was suggested for the degradation of AO dye over mesoporous CoTiO3/g-C3N4, and it was further supported by photoluminescence (PL) spectroscopy and photoelectrochemical responses. The present work demonstrates new insight and an approach to synthesizing mesoporous CoTiO3/g-C3N4 heterostructures for various potential applications.