Factors influencing the photocatalytic activity of alkali NbTa perovskites for hydrogen production from aqueous methanol solutions. (26th November 2016)

• Record Type: Journal Article
• Authors: Jana, P.; de la Peña O'Shea, V.A.; Mata Montero, C.; Pizarro, P.; Coronado, J.M.; Fresno, F.; Serrano, D.P.
• Is Part Of: International journal of hydrogen energy. Volume 41:Number 44(2016)
• Page Start: 19921
• Page End: 19928
• Publication Date: 2016-11-26
• Subjects: Photocatalytic H2 production -- Perovskite -- Tantalate -- Niobate; Hydrogen as fuel -- Periodicals; Hydrogène (Combustible) -- Périodiques; Hydrogen as fuel; Periodicals; 665.81
• DOI: 10.1016/j.ijhydene.2016.09.015
• Languages: English
• ISSNs: 0360-3199

Abstract

Abstract: The activity of ATa0.5 Nb0.5 O3 (A: Li, Na or K) photocatalysts for H2 production has been studied using methanol aqueous solutions. Previous studies showed that photocatalysts with 1:1 combination of Ta and Nb showed greatly improved activity compared to the single-metal oxides. In this work, compositional variations have shown that sodium suits best as alkali counterion for H2 evolution. Variation of reaction parameters like pH and methanol concentration shows that neutral pH and 10 vol.% methanol lead to the best activity of NaNb0.5 Ta0.5 O3 perovskite. In addition, a notable increase in the H2 evolution is observed by the use of Pt as co-catalyst, and the variation of its loading amount has also a great influence on the photocatalytic performance. The highest H2 production rate is obtained with the NaNb0.5 Ta0.5 O3 catalyst with 0.125 wt.% of Pt loading under UV irradiation. Graphical abstract: Highlights: A perovskite with 1:1 Ta:Nb molar ratio shows better photocatalytic H2 evolution activity than those with Nb or Ta only. Na as counterion gives the highest hydrogen production compared to Li and K. Neutral pH and 10 vol.% methanol lead to optimal hydrogen evolution. An optimal co-catalyst loading leads to the highest activity in 0.125 wt.%Pt/NaNb0.5 Ta0.5 O3 .