Engineering approach to enhance photocatalytic water splitting for dynamic H₂ production using La₂O₃/TiO₂ nanocatalyst in a monolith photoreactor

In this study, photocatalytic activity of La loaded TiO₂ NPs was enhanced by engineering approach using monolithic honeycomb assisted photo-reactor system for dynamic hydrogen production. La/TiO₂ NPs loaded over monolithic honeycomb support were characterized by XRD, XPS, FESEM, RAMAN, HRTEM, BET, UV–Vis and PL-spectroscopy. The photocatalytic activity of La/TiO₂ NPs was enhanced by 1.8 folds higher than using pristine TiO₂ in a slurry photoreactor system. This enactment was due to larger surface area, faster charge carrier separation and decreased surface recombination centers due to the presence of oxygen vacancies. Moreover, using monolithic honeycomb support loaded with La/TiO₂, H₂ generation rate of 165.5 ppm/h was obtained, 9.19 folds higher than using La/TiO₂ in a slurry phase. Moreover, apparent quantum yield and space yield of monolith photoreactor was 1.4 and 4.5 folds higher than the slurry phase photoreactor, respectively. The superior efficiency of monolith photoreactor was due to adaptable arrangement of reactor which permits most utilization of illuminated surface area and processing volume with effective mass transport which is restricted in a slurry phase photoreactor. Also, stability comparison of slurry and monolith photoreactor for hydrogen production reveals, reusability of La/TiO₂ loaded over monolithic support was 4.18% higher than the catalyst suspended in slurry phase photo-reactor. Therefore, enhanced efficiency of catalyst can be obtained using monolith photoreactor for photocatalytic H₂ production compared to suspended slurry system and can be employed for other energy applications.