Pillaring and NiOx co-catalyst loading as alternatives for the photoactivity enhancement of K2Ti4O9 towards water splitting

Autor(es)

Melo, Jr., Mauricio A. ^[1] ; Carminati, Saulo A. ^[1] ; Bettini, Jefferson ^[2] ; Nogueira, Ana F. ^[1]

Afiliação do(s) autor(es)

^[1] Univ Estadual Campinas, Inst Chem, UNICAMP, POB 6154, BR-13084971 Campinas, SP - Brazil

^[2] CNPEM, Natl Ctr Energy & Mat Res, Natl Nanotechnol Lab, BR-13083970 Campinas - Brazil

• Tipo de documento: Artigo Científico
• Fonte: SUSTAINABLE ENERGY & FUELS; v. 2, n. 5, p. 958-967, MAY 2018.
• Citações Web of Science: 2

Resumo

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 H-2 production from photocatalytic water splitting over K2Ti4O9 after pillaring with TiO2 pillars and loading of NiOx as a co-catalyst. The pillaring favored the charge carrier separation within the photocatalyst framework under illumination, whereas the NiOx co-catalyst, composed of nickel metal nanoparticles and nanostructured NiO, intensified the electronhole 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 H-2 evolution from 14.9 mmol, for the pristine K2Ti4O9, to 982.0 mmol, 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, NiOx as the co-catalyst proved to be as effective as platinum and more effective than Ag and Au in this particular system. (AU)

• Processo FAPESP: 13/05654-9 - Sólidos lamelares pilarizados com tio2 e dopados com nanopartículas para a fotorredução de dióxido de carbono e water splitting
• Beneficiário: Mauricio Alves de Melo Junior
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/22388-3 - Otimização da separação fotoquímica de cargas em interfaces nanométricas de fotocatalisadores para a melhora da eficiência de conversão de energia solar em combustível por water splitting
• Beneficiário: Mauricio Alves de Melo Junior
• Modalidade de apoio: Bolsas no Exterior - Estágio de Pesquisa - Pós-Doutorado