Highly efficient and sustainable photocatalytic H2 evolution on novel CuMn2O4/Bi2WO6 step-scheme heterostructure under visible light

Photocatalytic hydrogen generation procedures have recently garnered major interest as an achievable approach to harnessing solar power. Nevertheless, the low separation rates of photo-caused carriers and inadequate visible light uptake are the primary drawbacks of this methodology. This study provides a novel construction of a series of mesoporous CuMn2O4/Bi2WO6 step-scheme (CMO/BWO S-scheme) heterojunction photocatalysts through an easy sol-gel approach employing a non-ionic surfactant and varying quantities of CMO. The fabricated materials were characterized and evaluated through the evolution of H-2 under visible illumination. Structural, surface, and morphological examinations demonstrated that CMO was in close contact with BWO, creating an n-n heterojunction while preserving the mesoporous feature. Optical measurements indicated the expansion of absorbance edge in the fabricated CMO/BWO S-scheme photocatalysts compared to bare BWO and CMO. PL and photoelectrochemical (photocurrent response) measurements revealed significant enhancements in the mobility and separation of photo-caused charges. Therefore, the CMO/BWO S-scheme heterojunction photocatalysts exhibited notably higher efficacy towards H-2 generation than pristine BWO and CMO. The 15.0 % CMO/BWO S-scheme photocatalyst (optimal specimen) generated 31.98 mmol g(-1) H-2 at an optimized rate of 3.83 mmol g(-1) h(-1), >7.0 and 11.0 times faster than generated employing bare BWO and CMO, separately. Moreover, this novel S-scheme photocatalyst displayed high photostability with 99.7 % sustainability within 45 h of visible irradiation. This contribution not only offers a novel mesoporous heterostructure S-scheme photocatalytic system that was synthesized by a facile surfactant-encouraged sol-gel approach to achieve improved H-2 generation, but also presents novel prospects for the construction of novel heterostructure photocatalytic materials.