Pillaring and NiOx co-catalyst loading as alternatives for the photoactivity enhancement of K2Ti4O9 towards water splitting. Issue 5 (29th January 2018)

• Record Type: Journal Article
• Authors: Melo, Mauricio A.; Carminati, Saulo A.; Bettini, Jefferson; Nogueira, Ana F.
• Is Part Of: Sustainable energy & fuels. Volume 2:Issue 5(2018)
• Page Start: 958
• Page End: 967
• Publication Date: 2018-01-29
• Subjects: Renewable energy sources -- Periodicals; Fuel cells -- Periodicals; Electric batteries -- Periodicals; Electrochemistry -- Periodicals; 660.297
• DOI: 10.1039/c7se00589j
• Languages: English
• ISSNs: 2398-4902

Abstract

Abstract : Combining TiO2 pillaring with the loading of the NiO x co-catalyst can boost the water splitting hydrogen production over K2 Ti4 O9 66 times. Abstract : Structural improvements of efficient and abundant photocatalysts and the employment of less expensive co-catalysts are appealing routes to promote the development of economically viable solar fuel production. We herein report a significant enhancement of the H2 production from photocatalytic water splitting over K2 Ti4 O9 after pillaring with TiO2 pillars and loading of NiO x as a co-catalyst. The pillaring favored the charge carrier separation within the photocatalyst framework under illumination, whereas the NiO x co-catalyst, composed of nickel metal nanoparticles and nanostructured NiO, intensified the electron–hole separation at the surface. These are unprecedented results indicated by surface photovoltage spectroscopy, which was applied for the first time in this kind of photocatalyst composite. All modifications enhanced the H2 evolution from 14.9 μmol, for the pristine K2 Ti4 O9, to 982.0 μmol, for the final product, after 7 h of irradiation tests using methanol as a hole scavenger. This boost was also favored by the mesoporosity and high surface area created by the pillaring process. Moreover, NiO x as the co-catalyst proved to be as effective as platinum and more effective than Ag and Au in this particular system.