Visible light-activated S-scheme CuAl2O4/Bi2WO6 heterostructure for sustainable and highly efficient H2 generation

Solar light-motivated hydrogen production on particulate semiconducting photocatalysts has become a sacred grail of sustainability, facing current energy and environmental challenges. Creating an S-scheme heterojunction photocatalyst, on the other hand, is a workable way to get around the problems that come up with conventional photocatalysis, which makes photocatalysis more effective. In this work, the S-scheme heterostructure CuAl2O4/ Bi2WO6 (CAO/BWO) materials were constructed through a facile sol-gel-impregnating route. The constructed CAO/BWO photocatalysts were employed for photocatalytic H2 generation in the presence of glycerol as a hole scavenger, and in situ photo-deposited Pt as an electron trapper and co-catalyst, under visible light illumination. The thorough investigations of the yielded materials revealed that diverse amounts of CAO nanoparticles (NPs) were distributed on the surface of the nanosheet-structured BWO, forming S-scheme CAO/BWO photocatalysts. The introduction of CAO NPs on BWO crystals exhibited synergistic influences on semiconductor characteristics and light-sucking extent without considerable alterations in the fundamental crystallographic or surface configuration. The inclusion of 12.0 wt% CAO resulted in a significant enhancement for visible light response as well as photo-induced carriers' separation and kinetics in the constructed heterostructure photocatalyst. The 12.0 wt%% CAO/BWO (2.5 g L-1) has generated H2 of 35.18 mmol g-1 and with an enhanced rate of 4.21 mmol g-1 h-1 that is about 7.0-fold higher than pristine BWO. Also, this novel catalyst exhibited strong stability with 99.7 % sustainability within five independent runs. The S-scheme heterostructure construction provides a promising technology for improving heterogeneous photocatalysis efficacy and performance in sustainable and green energy production.